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Kodate N, Kohli P, McGinn C, Scott R, Ross E, Treusch P, Maeda Y, Donnelly S, Leonard C, Cogan L, Mannan H, O’Shea D, Obayashi K, Masuyama S. 43 EXPLORING STAFF PERCEPTIONS AND ATTITUDES TO CARE AND CAREBOTS: THE CASE OF AN ORIGINAL AIR-DISINFECTION ROBOT IN IRELAND. Age Ageing 2022. [DOI: 10.1093/ageing/afac218.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
The pandemic heightened the sense of security and safety in care settings, with cleanliness and infection control becoming an even more important aspect of care delivery. Although the impact of new welfare technology on health and social care has been discussed in recent years, few studies have reported the implementation processes or human-robot interactions in care facilities in different cultural settings. The aims of this interdisciplinary research therefore were to understand needs and aspects that have to be considered for implementing an assistive robot, and to explore user perceptions, and the process by which the robots are adopted in Ireland and Japan.
Methods
An original air-disinfection robot (V-Air) was developed by Akara Robotics, as part of research project “Harmonisation towards the establishment of Person-centred, Robotics-aided Care System” (Toyota Foundation, D18-ST-0005). Prior to its instalment in a rehabilitation centre in Dublin, semi-structured interviews were conducted, and observations carried out with seven care professionals, as they interacted with V-Air. The robot was then trialled for eight weeks (March-May 2022) in selected areas of the facility. After four weeks, the users filled out the System Usability Score and were asked questions at the end of the trial. Their scores and answers to the questions revealed staff perceptions and attitudes to care robots.
Results
Overall, the users had positive perceptions of V-Air and its usability. Initial differences existed in staff’s confidence levels, depending on prior experiences with technologies. Collective sensemaking was observed, particularly, around care delivery processes and robot functionalities. The adoption process was facilitated by several factors such as the timing of introduction, user-centred design, concept of care and organisational support.
Conclusion
The findings suggest that the introduction of care robots in care settings can offer an additional layer of organisational safety, while highlighting the significance of the iterative process in adopting assistive technologies.
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Affiliation(s)
- N Kodate
- University College Dublin School of Social Policy, Social Work and Social Justice, , Dublin, Ireland
- Universal Accessibility & Ageing Research Centre , Nishitokyo, Japan
- Hokkaido University Public Policy Research Center, , Sapporo, Japan
- L’École des Hautes Etudes En Sciences Sociales, Fondation France Japon , Paris, France
- University of Tokyo Institute for Future Initiatives, , Tokyo, Japan
| | - P Kohli
- Maynooth University Department of Sociology, , Maynooth, Ireland
| | - C McGinn
- Trinity College Dublin Department of Mechanical, Manufacturing & Biomedical Engineering, , Dublin, Ireland
- Akara Robotics , Dublin, Ireland
| | - R Scott
- Akara Robotics , Dublin, Ireland
| | - E Ross
- Royal Hospital Donnybrook , Dublin, Ireland
| | - P Treusch
- Trinity College Dublin Trinity Long Room Hub, , Dublin, Ireland
| | - Y Maeda
- Technological University Dublin , Dublin, Ireland
| | - S Donnelly
- University College Dublin School of Social Policy, Social Work and Social Justice, , Dublin, Ireland
| | - C Leonard
- Royal Hospital Donnybrook , Dublin, Ireland
| | - L Cogan
- Royal Hospital Donnybrook , Dublin, Ireland
| | - H Mannan
- University College Dublin School of Nursing, Midwifery and Health System, , Dublin, Ireland
| | - D O’Shea
- St. Vincent’s University Hospital , Dublin, Ireland
| | - K Obayashi
- Nihon Fukushi University Faculty of Healthcare Management, , Mihama, Japan
- Social Welfare Corporation Tokyo Seishin-kai , Nishitokyo, Japan
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Jiao K, Becerra-Mora N, Russell B, Migone A, Gemeinhardt ME, Goodson BM, Kohli P. Simultaneous Writing and Erasing Using Probe Lithography Synchronized Erasing and Deposition (PLiSED). Langmuir 2022; 38:12630-12643. [PMID: 36201686 DOI: 10.1021/acs.langmuir.2c02096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Simultaneous writing and erasing of two and three molecules in one single step at the microscale using Polymeric Lithography Editor (PLE) probes is demonstrated. Simultaneous writing and erasing of three molecules was accomplished by rastering a nanoporous probe that was loaded with rhodamine B and fluorescein over a quinine-coated glass substrate. The solvated quinine molecules were erased and transported into the probe matrix, whereas both rhodamine and fluorescein molecules were simultaneously deposited and aligned with the path of the erased quinine on the substrate. The simultaneous writing and erasing of molecules is referred to as PLiSED. The writing and erasing speed can be easily tuned by adjusting the probe speed to as large as 10,000 μm2/s. The microscale patterns on the orders of square millimeter area were fabricated by erasing fluorescein with an efficiency (ηe) > 95% while simultaneously depositing rhodamine molecules at the erased spots. The roles of the probe porosity, transport medium, and kinetics of solvation for editing were also investigated─the presence of a transport medium at the probe-substrate interface is required for the transport of the molecules into and out of the probe. The physical and mechanical properties of the polymeric probes influenced molecular editing. Young's modulus values of the hydrated hydrogels composed of varying monomer/cross-linker ratios were estimated using atomic force microscopy. Probes with the highest observed erasing capacity were used for further experiments to investigate the effects of relative humidity and erasing time on editing. Careful control over experimental conditions provided high-quality editing of microscale patterns at high editing speed. Combining erasing and deposition of multiple molecules in one single step offers a unique opportunity to significantly improve the efficiency and the accuracy of lithographic editing at the microscale. PLiSED enables rapid on-site lithographic rectification and has considerable application values in high-quality lithography and solid surface modification.
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Affiliation(s)
- Kexin Jiao
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Nathalie Becerra-Mora
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Brice Russell
- School of Physics and Applied Physics, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Aldo Migone
- School of Physics and Applied Physics, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Max E Gemeinhardt
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Boyd M Goodson
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
- Materials Technology Center, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Punit Kohli
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
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3
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Zampieri S, Sandri M, Cheatwood JL, Balaraman RP, Anderson LB, Cobb BA, Latour CD, Hockerman GH, Kern H, Sartori R, Ravara B, Merigliano S, Da Dalt G, Davie JK, Kohli P, Pond AL. The ERG1A K + Channel Is More Abundant in Rectus abdominis Muscle from Cancer Patients Than that from Healthy Humans. Diagnostics (Basel) 2021; 11:diagnostics11101879. [PMID: 34679577 PMCID: PMC8534910 DOI: 10.3390/diagnostics11101879] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND The potassium channel encoded by the ether-a-gogo-related gene 1A (erg1a) has been detected in the atrophying skeletal muscle of mice experiencing either muscle disuse or cancer cachexia and further evidenced to contribute to muscle deterioration by enhancing ubiquitin proteolysis; however, to our knowledge, ERG1A has not been reported in human skeletal muscle. METHODS AND RESULTS Here, using immunohistochemistry, we detect ERG1A immunofluorescence in human Rectus abdominis skeletal muscle sarcolemma. Further, using single point brightness data, we report the detection of ERG1A immunofluorescence at low levels in the Rectus abdominis muscle sarcolemma of young adult humans and show that it trends toward greater levels (10.6%) in healthy aged adults. Interestingly, we detect ERG1A immunofluorescence at a statistically greater level (53.6%; p < 0.05) in the skeletal muscle of older cancer patients than in age-matched healthy adults. Importantly, using immunoblot, we reveal that lower mass ERG1A protein is 61.5% (p < 0.05) more abundant in the skeletal muscle of cachectic older adults than in healthy age-matched controls. Additionally, we report that the ERG1A protein is detected in a cultured human rhabdomyosarcoma line that may be a good in vitro model for the study of ERG1A in muscle. CONCLUSIONS The data demonstrate that ERG1A is detected more abundantly in the atrophied skeletal muscle of cancer patients, suggesting it may be related to muscle loss in humans as it has been shown to be in mice experiencing muscle atrophy as a result of malignant tumors.
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Affiliation(s)
- Sandra Zampieri
- Department of Surgery, Oncology and Gastroenterology, University of Padova, 35122 Padova, Italy; (S.Z.); (B.R.); (S.M.); (G.D.D.)
- Department of Biomedical Sciences, University of Padova, 35122 Padova, Italy; (M.S.); (R.S.)
| | - Marco Sandri
- Department of Biomedical Sciences, University of Padova, 35122 Padova, Italy; (M.S.); (R.S.)
| | - Joseph L. Cheatwood
- Anatomy Department, Southern Illinois University School of Medicine, Carbondale, IL 62902, USA; (J.L.C.); (L.B.A.); (B.A.C.)
| | - Rajesh P. Balaraman
- Department of Chemistry and Biochemistry, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA; (R.P.B.); (P.K.)
| | - Luke B. Anderson
- Anatomy Department, Southern Illinois University School of Medicine, Carbondale, IL 62902, USA; (J.L.C.); (L.B.A.); (B.A.C.)
| | - Brittan A. Cobb
- Anatomy Department, Southern Illinois University School of Medicine, Carbondale, IL 62902, USA; (J.L.C.); (L.B.A.); (B.A.C.)
| | - Chase D. Latour
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA;
| | - Gregory H. Hockerman
- Medicinal Chemistry and Molecular Pharmacology Department, Purdue University School of Pharmacy, West Lafayette, IN 47906, USA;
| | - Helmut Kern
- Physiko-und Rheumatherapie GmbH, 3100 St. Poelten, Austria;
| | - Roberta Sartori
- Department of Biomedical Sciences, University of Padova, 35122 Padova, Italy; (M.S.); (R.S.)
| | - Barbara Ravara
- Department of Surgery, Oncology and Gastroenterology, University of Padova, 35122 Padova, Italy; (S.Z.); (B.R.); (S.M.); (G.D.D.)
| | - Stefano Merigliano
- Department of Surgery, Oncology and Gastroenterology, University of Padova, 35122 Padova, Italy; (S.Z.); (B.R.); (S.M.); (G.D.D.)
| | - Gianfranco Da Dalt
- Department of Surgery, Oncology and Gastroenterology, University of Padova, 35122 Padova, Italy; (S.Z.); (B.R.); (S.M.); (G.D.D.)
| | - Judith K. Davie
- Biochemistry Department, Southern Illinois University School of Medicine, Carbondale, IL 62902, USA;
| | - Punit Kohli
- Department of Chemistry and Biochemistry, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA; (R.P.B.); (P.K.)
| | - Amber L. Pond
- Anatomy Department, Southern Illinois University School of Medicine, Carbondale, IL 62902, USA; (J.L.C.); (L.B.A.); (B.A.C.)
- Correspondence:
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4
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Honigberg M, Lahm T, Wood M, Ho J, Kohli P, Natarajan P. Association of premature menopause with incident pulmonary hypertension. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.3173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Several forms of pulmonary hypertension (PH) disproportionately affect women. Prior animal and human studies suggest that oestradiol exerts mixed effects on the pulmonary vasculature. Whether premature menopause represents a risk factor for PH is currently unknown.
Purpose
To test the independent association of premature menopause with incident PH.
Methods
We included women in the UK Biobank who were 40–69 years old and postmenopausal at enrolment and underwent pulmonary function testing at the baseline study visit. Women with missing menopause data, prevalent PH, extreme pulmonary function test outliers (Z>5 or Z<−5), and those with congenital heart disease were excluded. Premature menopause was defined as occurring before age 40 years. Reproductive history, including age at menopause and use of menopausal hormone therapy (MHT), was ascertained by participant self-report at enrolment. PH risk factors and relevant co-morbidities were captured by participant self-report and by ICD code. Incident PH was ascertained by the appearance of a qualifying ICD code (ICD-9 4160; ICD-10 I27.0, I27.2). Follow-up began at study enrolment, with time to censoring determined by date of PH diagnosis or last encounter in the medical record. Multivariable Cox proportional hazard models tested the association between premature menopause and incident PH, with adjustment for age, race, ever-smoking, body-mass index, systolic blood pressure, antihypertensive medication use, non-high-density lipoprotein cholesterol, cholesterol-lowering medication use, C-reactive protein, prevalent type 2 diabetes, obstructive sleep apnoea, heart failure, venous thromboembolism, mitral regurgitation, aortic stenosis, forced vital capacity (FVC), the forced expiratory volume in 1 second (FEV1)/FVC ratio, and ever-use of MHT.
Results
Among 138,518 postmenopausal women (mean [SD] age at enrolment 60.0 [5.4] years), 5,440 women (3.9%) had a history of premature menopause. Incident PH was diagnosed in 253 women over a median 8.1 (interquartile range 7.4–8.8) years of follow-up. Mean age at menopause was 48.3 (6.4) years among women with incident PH vs. 49.7 (5.1) years among those without PH (P<0.001). Crude cumulative incidence of PH was 0.40% among women premature menopause vs. 0.17% among those without (Figure 1). After multivariable adjustment, premature menopause remained independently associated with PH (hazard ratio [HR] 1.91, 95% CI 1.15–3.16, P=0.01). Ever-use of MHT was not significantly associated with incident PH (HR 0.93, 95% CI 0.68–1.26, P=0.62). In sensitivity analysis excluding 4,461 women with prevalent heart failure, venous thromboembolism, mitral regurgitation, or aortic stenosis, the HR for PH associated with premature menopause was 2.19 (95% CI 1.28–3.74, P=0.004).
Conclusions
Premature menopause is an independent risk factor for PH in women.
Figure 1
Funding Acknowledgement
Type of funding source: Other. Main funding source(s): U.S. National Heart, Lung, and Blood Institute
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Affiliation(s)
- M Honigberg
- Massachusetts General Hospital, Boston, United States of America
| | - T Lahm
- Indiana University School of Medicine, Indianapolis, United States of America
| | - M Wood
- Massachusetts General Hospital, Boston, United States of America
| | - J Ho
- Massachusetts General Hospital, Boston, United States of America
| | - P Kohli
- Massachusetts General Hospital, Boston, United States of America
| | - P Natarajan
- Massachusetts General Hospital, Boston, United States of America
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5
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Adhikari A, Cobb B, Eddington S, Becerra N, Kohli P, Pond A, Davie J. IFN-γ and CIITA modulate IL-6 expression in skeletal muscle. Cytokine X 2020; 2:100023. [PMID: 33604554 PMCID: PMC7885875 DOI: 10.1016/j.cytox.2020.100023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/04/2020] [Accepted: 03/08/2020] [Indexed: 12/20/2022] Open
Abstract
Interleukin 6 (IL-6) is a secreted cytokine that is an important mediator of the immune response in numerous tissues, including skeletal muscle. IL-6 is considered a myokine as it can be secreted by muscle. IL-6 is secreted following exercise, where it exerts both pro-myogenic effects as well as anti-myogenic effects such as promoting atrophy and muscle wasting. The regulation of IL-6 in skeletal muscle is not well understood. The purpose of this study was to determine if IFN-γ and TNF-ɑ stimulate IL-6 in skeletal muscle. We found that both IFN-γ and TNF-α stimulate IL-6 in skeletal muscle, but the stimulation is not cooperative as seen in monocytes. We have previously shown that the IFN-γ stimulated class II major histocompatibility complex transactivator (CIITA) mediates many of the effects of IFN-γ in skeletal muscle and we show here that CIITA directly stimulates IL-6. The regulation of IL-6 by CIITA is clearly complex, as we found that CIITA both stimulates and restrains IL-6 expression. To show that these effects could be observed in a physiological setting, mice were treated with IFN-γ and we found that both CIITA and IL-6 were upregulated in skeletal muscle.
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Affiliation(s)
- Abhinav Adhikari
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL, USA
| | - Brittan Cobb
- Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, IL, USA
| | - Seth Eddington
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL, USA
| | - Nathalie Becerra
- Department of Chemistry, Southern Illinois Carbondale, Carbondale, IL, USA
| | - Punit Kohli
- Department of Chemistry, Southern Illinois Carbondale, Carbondale, IL, USA
| | - Amber Pond
- Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, IL, USA
| | - Judith Davie
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL, USA
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6
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Pond AL, Zampieri S, Sandri M, Cheatwood J, Kohli P, Balaraman R, Anderson LB, Latour CD, Hockerman GH, Kern H, Sartori R, Merigiano S, Da Dalt G, Davie JK, Carraro U. The ERG1 Potassium Channel is Abundant in Cachectic Human Skeletal Muscle. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.05573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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7
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Dogra N, Balaraman RP, Kohli P. Chemically Engineered Synthetic Lipid Vesicles for Sensing and Visualization of Protein-Bilayer Interactions. Bioconjug Chem 2019; 30:2136-2149. [PMID: 31314501 DOI: 10.1021/acs.bioconjchem.9b00366] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
From pathogen intrusion to immune response, the cell membrane plays an important role in signal transduction. Such signals are important for cellular proliferation and survival. However, measurement of these subtle signals through the lipid membrane scaffold is challenging. We present a chromatic model membrane vesicle system engineered to covalently bind with lysine residues of protein molecules for investigation of cellular interactions and signaling. We discovered that different protein molecules induced differential spectroscopic signals, which is based on the chemical and physical properties of protein interacting at the vesicle surface. The observed chromatic response (CR) for bound protein molecules with higher molecular weight was much larger (∼5-15×) than those for low molecular weight proteins. Through mass spectrometry (MS), we found that only 6 out of 60 (10%) lysine groups present in bovine serum albumin (BSA) were accessible to the membrane of the vesicles. Finally, a "sphere-shell" model representing the protein-vesicle complex was used for evaluating the contribution of van der Waals interactions between proteins and vesicles. Our analysis points to contributions from van der Waals, hydrophobic, and electrostatic interactions toward observed CR signals resulting from molecular interactions at the vesicle membrane surface. Overall, this study provided a convenient, chromatic, semiquantitative method of detecting biomolecules and their interactions with model membranes at sub-nanomolar concentration.
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Affiliation(s)
- Navneet Dogra
- Department of Chemistry and Biochemistry , Southern Illinois University , Carbondale , Illinois 62901 , United States.,IBM T. J. Watson Research Center , Yorktown Heights , New York 10058 , United States.,Department of Genetics and Genomic Sciences , Icahn School of Medicine at Mount Sinai , New York , New York 10029 , United States
| | - Rajesh P Balaraman
- Department of Chemistry and Biochemistry , Southern Illinois University , Carbondale , Illinois 62901 , United States
| | - Punit Kohli
- Department of Chemistry and Biochemistry , Southern Illinois University , Carbondale , Illinois 62901 , United States
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8
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Wang X, Guo X, Ye J, Zheng N, Kohli P, Choi D, Zhang Y, Xie Z, Zhang Q, Luan H, Nan K, Kim BH, Xu Y, Shan X, Bai W, Sun R, Wang Z, Jang H, Zhang F, Ma Y, Xu Z, Feng X, Xie T, Huang Y, Zhang Y, Rogers JA. Freestanding 3D Mesostructures, Functional Devices, and Shape-Programmable Systems Based on Mechanically Induced Assembly with Shape Memory Polymers. Adv Mater 2019; 31:e1805615. [PMID: 30370605 DOI: 10.1002/adma.201805615] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/02/2018] [Indexed: 05/23/2023]
Abstract
Capabilities for controlled formation of sophisticated 3D micro/nanostructures in advanced materials have foundational implications across a broad range of fields. Recently developed methods use stress release in prestrained elastomeric substrates as a driving force for assembling 3D structures and functional microdevices from 2D precursors. A limitation of this approach is that releasing these structures from their substrate returns them to their original 2D layouts due to the elastic recovery of the constituent materials. Here, a concept in which shape memory polymers serve as a means to achieve freestanding 3D architectures from the same basic approach is introduced, with demonstrated ability to realize lateral dimensions, characteristic feature sizes, and thicknesses as small as ≈500, 10, and 5 µm simultaneously, and the potential to scale to much larger or smaller dimensions. Wireless electronic devices illustrate the capacity to integrate other materials and functional components into these 3D frameworks. Quantitative mechanics modeling and experimental measurements illustrate not only shape fixation but also capabilities that allow for structure recovery and shape programmability, as a form of 4D structural control. These ideas provide opportunities in fields ranging from micro-electromechanical systems and microrobotics, to smart intravascular stents, tissue scaffolds, and many others.
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Affiliation(s)
- Xueju Wang
- Simpson Querrey Institute and Feinberg Medical School, Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
- Department of Mechanical and Aerospace Engineering, University of Missouri-Columbia, Columbia, MO, 65211, USA
| | - Xiaogang Guo
- Center for Mechanics and Materials, Center for Flexible Electronics Technology, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, P. R. China
| | - Jilong Ye
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, 100084, P. R. China
| | - Ning Zheng
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Punit Kohli
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Dongwhi Choi
- Department of Mechanical Engineering, Kyung Hee University, Yongin, 17104, South Korea
| | - Yi Zhang
- Simpson Querrey Institute and Feinberg Medical School, Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
- Department of Biomedical, Biological and Chemical Engineering, University of Missouri-Columbia, Columbia, MO, 65211, USA
| | - Zhaoqian Xie
- Departments of Civil and Environmental Engineering Mechanical Engineering, and Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Qihui Zhang
- Simpson Querrey Institute and Feinberg Medical School, Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
| | - Haiwen Luan
- Departments of Civil and Environmental Engineering Mechanical Engineering, and Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Kewang Nan
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Bong Hoon Kim
- Simpson Querrey Institute and Feinberg Medical School, Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
| | - Yameng Xu
- Simpson Querrey Institute and Feinberg Medical School, Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
| | - Xiwei Shan
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Wubin Bai
- Simpson Querrey Institute and Feinberg Medical School, Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
| | - Rujie Sun
- Bristol Composites Institute (ACCIS), University of Bristol, Bristol, BS8 1TR, UK
| | - Zizheng Wang
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Hokyung Jang
- Simpson Querrey Institute and Feinberg Medical School, Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
| | - Fan Zhang
- Center for Mechanics and Materials, Center for Flexible Electronics Technology, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, P. R. China
| | - Yinji Ma
- Center for Mechanics and Materials, Center for Flexible Electronics Technology, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, P. R. China
| | - Zheng Xu
- Center for Mechanics and Materials, Center for Flexible Electronics Technology, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, P. R. China
- The State Key Laboratory for Manufacturing and Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Xue Feng
- Center for Mechanics and Materials, Center for Flexible Electronics Technology, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, P. R. China
| | - Tao Xie
- State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Yonggang Huang
- Departments of Civil and Environmental Engineering Mechanical Engineering, and Materials Science and Engineering, Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
| | - Yihui Zhang
- Center for Mechanics and Materials, Center for Flexible Electronics Technology, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, P. R. China
| | - John A Rogers
- Simpson Querrey Institute and Feinberg Medical School, Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA
- Department of Materials Science and Engineering Biomedical Engineering, Neurological Surgery, Chemistry, Mechanical Engineering, Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, 60208, USA
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Dhital R, Mora NB, Watson DG, Kohli P, Choudhary R. Efficacy of limonene nano coatings on post-harvest shelf life of strawberries. Lebensm Wiss Technol 2018. [DOI: 10.1016/j.lwt.2018.06.038] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Sekine Y, Kim SB, Zhang Y, Bandodkar AJ, Xu S, Choi J, Irie M, Ray TR, Kohli P, Kozai N, Sugita T, Wu Y, Lee K, Lee KT, Ghaffari R, Rogers JA. A fluorometric skin-interfaced microfluidic device and smartphone imaging module for in situ quantitative analysis of sweat chemistry. Lab Chip 2018; 18:2178-2186. [PMID: 29955754 DOI: 10.1039/c8lc00530c] [Citation(s) in RCA: 121] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The rich composition of solutes and metabolites in sweat and its relative ease of collection upon excretion from skin pores make this class of biofluid an attractive candidate for point of care analysis. Wearable technologies that combine electrochemical sensors with conventional or emerging semiconductor device technologies offer valuable capabilities in sweat sensing, but they are limited to assays that support amperometric, potentiometric, and colorimetric analyses. Here, we present a complementary approach that exploits fluorometric sensing modalities integrated into a soft, skin-interfaced microfluidic system which, when paired with a simple smartphone-based imaging module, allows for in situ measurement of important biomarkers in sweat. A network array of microchannels and a collection of microreservoirs pre-filled with fluorescent probes that selectively react with target analytes in sweat (e.g. probes), enable quantitative, rapid analysis. Field studies on human subjects demonstrate the ability to measure the concentrations of chloride, sodium and zinc in sweat, with accuracy that matches that of conventional laboratory techniques. The results highlight the versatility of advanced fluorescent-based imaging modalities in body-worn sweat microfluidics platforms, and they suggest some practical potential for these ideas.
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Affiliation(s)
- Yurina Sekine
- Materials Sciences Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan.
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11
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Flynn Bolte KT, Balaraman RP, Jiao K, Tustison M, Kirkwood KS, Zhou C, Kohli P. Probing Liquid-Solid and Vapor-Liquid-Solid Interfaces of Hierarchical Surfaces Using High-Resolution Microscopy. Langmuir 2018; 34:3720-3730. [PMID: 29486565 DOI: 10.1021/acs.langmuir.8b00298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Liquid-solid (LS) and vapor-liquid-solid (VLS) interfaces are important for the fundamental understanding of how surface chemistry impacts industrial processes and applications. Superhydrophobic surfaces, from structural hierarchies, were fabricated by coating flat smooth surfaces with hollow glass microspheres. These surfaces are referred to as structural hierarchical-modified microsphere surfaces (SHiMMs). Two-phase LS and three-phase VLS interfaces of water droplets on SHiMMs, with an apparent static contact angle (aSCA) of ∼160°, were probed at microscale using environmental scanning electron microscopy (ESEM) and high-resolution optical microscopy (OM). Both ESEM and OM confirmed the presence of air pockets in 3-150 μm range at the VLS triple-phase of the droplet peripheral contact line. The wetting characteristics of the LS interface in the interior of the water droplet were probed using energy-dispersive spectroscopy, which corroborated well with the VLS triple-phase observations, confirming the presence of both the microscale air pockets and fractional complete wetting of the SHiMMs. The superhydrophobic water droplets on the SHiMMs also exhibited relatively high adhesion to the SHiMMs-a tilt angle of 10°-40° was needed for detaching the droplets off the surfaces. Semiquantitative three-phase contact-line analysis and experimental data indicated high-water aSCA, and large adhesion on the microscale-roughened SHiMMs is attributed to pinning of the probe liquid both at the triple VLS and interior LS interfaces. The control over microroughness and surface chemistry of the SHiMMs will allow tuning of both the static and dynamic liquid-surface interactions.
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Affiliation(s)
| | | | | | | | | | | | - Punit Kohli
- Department of Chemistry and Biochemistry , Southern Illinois University , Carbondale , Illinois 62901 , United States
- Department of Materials Science and Engineering , Northwestern University , Evanston , Illinois 60201 , United States
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12
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Dhital R, Joshi P, Becerra-Mora N, Umagiliyage A, Chai T, Kohli P, Choudhary R. Integrity of edible nano-coatings and its effects on quality of strawberries subjected to simulated in-transit vibrations. Lebensm Wiss Technol 2017. [DOI: 10.1016/j.lwt.2017.02.033] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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13
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Kohli P, Soler ZM, Storck KA, Shahangian A, Banglawala SM, Schlosser RJ. Responsiveness and reliability of the Sinus Control Test in chronic rhinosinusitis. Rhinology 2017; 55:39-44. [PMID: 28025986 DOI: 10.4193/rhin16.208] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND The Sinus Control Test (SCT) is a patient-reported questionnaire designed to help physicians identify sub-optimally controlled chronic rhinosinusitis (CRS). This study measures responsiveness to surgery and reliability of the SCT. METHODOLOGY Adults meeting diagnostic criteria for CRS were recruited from rhinology clinics at a tertiary academic institution. To measure responsiveness, the SCT was administered at baseline and at least 3 months after surgery to 62 CRS patients. To measure reliability, the SCT was administered at two clinical encounters a maximum of 14 days apart to 22 CRS patients. RESULTS Total SCT scores significantly improved from baseline to post-operative follow-up, and the distribution of patients with total SCT scores falling into the uncontrolled, partially controlled, and controlled categories before and after surgery were significantly different in the direction of improvement. The SCT met minimum standards for reliability and internal consistency as measured by: test-retest reliability coefficient, intra-class correlation coefficients, and item-total correlations. Cronbach alpha; values with each item deleted were lower than the overall Cronbach alpha. The SCT captures the full range of disease control as measured by floor and ceiling effects. CONCLUSION The SCT is responsive to surgical intervention and a reliable tool to monitor changes in CRS control levels.
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Affiliation(s)
- P Kohli
- Division of Rhinology and Sinus Surgery, Department of Otolaryngology, Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - Z M Soler
- Division of Rhinology and Sinus Surgery, Department of Otolaryngology, Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - K A Storck
- Division of Rhinology and Sinus Surgery, Department of Otolaryngology, Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - A Shahangian
- Division of Rhinology and Sinus Surgery, Department of Otolaryngology, Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - S M Banglawala
- Department of Otolaryngology, Head and Neck Surgery, University of Toronto, Toronto, ON, Canada
| | - R J Schlosser
- Otolaryngology, Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, USA
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14
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Rajasekaran PR, Zhou C, Dasari M, Voss KO, Trautmann C, Kohli P. Polymeric lithography editor: Editing lithographic errors with nanoporous polymeric probes. Sci Adv 2017; 3:e1602071. [PMID: 28630898 PMCID: PMC5466373 DOI: 10.1126/sciadv.1602071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 03/23/2017] [Indexed: 06/11/2023]
Abstract
A new lithographic editing system with an ability to erase and rectify errors in microscale with real-time optical feedback is demonstrated. The erasing probe is a conically shaped hydrogel (tip size, ca. 500 nm) template-synthesized from track-etched conical glass wafers. The "nanosponge" hydrogel probe "erases" patterns by hydrating and absorbing molecules into a porous hydrogel matrix via diffusion analogous to a wet sponge. The presence of an interfacial liquid water layer between the hydrogel tip and the substrate during erasing enables frictionless, uninterrupted translation of the eraser on the substrate. The erasing capacity of the hydrogel is extremely high because of the large free volume of the hydrogel matrix. The fast frictionless translocation and interfacial hydration resulted in an extremely high erasing rate (~785 μm2/s), which is two to three orders of magnitude higher in comparison with the atomic force microscopy-based erasing (~0.1 μm2/s) experiments. The high precision and accuracy of the polymeric lithography editor (PLE) system stemmed from coupling piezoelectric actuators to an inverted optical microscope. Subsequently after erasing the patterns using agarose erasers, a polydimethylsiloxane probe fabricated from the same conical track-etched template was used to precisely redeposit molecules of interest at the erased spots. PLE also provides a continuous optical feedback throughout the entire molecular editing process-writing, erasing, and rewriting. To demonstrate its potential in device fabrication, we used PLE to electrochemically erase metallic copper thin film, forming an interdigitated array of microelectrodes for the fabrication of a functional microphotodetector device. High-throughput dot and line erasing, writing with the conical "wet nanosponge," and continuous optical feedback make PLE complementary to the existing catalog of nanolithographic/microlithographic and three-dimensional printing techniques. This new PLE technique will potentially open up many new and exciting avenues in lithography, which remain unexplored due to the inherent limitations in error rectification capabilities of the existing lithographic techniques.
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Affiliation(s)
| | - Chuanhong Zhou
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
| | - Mallika Dasari
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
| | | | - Christina Trautmann
- GSI Helmholtzzentrum, 64291 Darmstadt, Germany
- Technische Universität, 64289 Darmstadt, Germany
| | - Punit Kohli
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
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15
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Abrams JS, Howe SE, Becerra N, Kohli P, Konjufca V. Immunogenicity of antigen-conjugated biodegradable polydiacetylene liposomes administered mucosally. J Biomed Mater Res A 2016; 105:557-565. [DOI: 10.1002/jbm.a.35938] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/30/2016] [Accepted: 10/13/2016] [Indexed: 12/23/2022]
Affiliation(s)
| | - Savannah E. Howe
- Department of Microbiology; Southern Illinois University; Carbondale Illinois
| | - Nathalie Becerra
- Department of Chemistry; Southern Illinois University; Carbondale Illinois
| | - Punit Kohli
- Department of Chemistry; Southern Illinois University; Carbondale Illinois
| | - Vjollca Konjufca
- Department of Microbiology; Southern Illinois University; Carbondale Illinois
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16
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Abstract
Desktop wax printer was employed to build high throughput platforms for studying stem cells fate.
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Affiliation(s)
- Ahmad Z. Qamar
- Department of Chemistry and Biochemistry
- Southern Illinois University Carbondale
- USA
| | - Kshitij Amar
- Department of Mechanical Engineering and Energy Processes
- Southern Illinois University Carbondale
- USA
| | - Punit Kohli
- Department of Chemistry and Biochemistry
- Southern Illinois University Carbondale
- USA
| | - Farhan Chowdhury
- Department of Mechanical Engineering and Energy Processes
- Southern Illinois University Carbondale
- USA
| | - Mohtashim H. Shamsi
- Department of Chemistry and Biochemistry
- Southern Illinois University Carbondale
- USA
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Makwana S, Choudhary R, Haddock J, Kohli P. In-vitro antibacterial activity of plant based phenolic compounds for food safety and preservation. Lebensm Wiss Technol 2015. [DOI: 10.1016/j.lwt.2015.02.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Dogra N, Choudhary R, Kohli P, Haddock JD, Makwana S, Horev B, Vinokur Y, Droby S, Rodov V. Polydiacetylene nanovesicles as carriers of natural phenylpropanoids for creating antimicrobial food-contact surfaces. J Agric Food Chem 2015; 63:2557-2565. [PMID: 25697369 DOI: 10.1021/jf505442w] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The ultimate goal of this study was developing antimicrobial food-contact materials based on natural phenolic compounds using nanotechnological approaches. Among the methyl-β-cyclodextrin-encapsulated phenolics tested, curcumin showed by far the highest activity toward Escherichia coli with a minimum inhibitory concentration of 0.4 mM. Curcumin was enclosed in liposome-type polydiacetylene/phosholipid nanovesicles supplemented with N-hydroxysuccinimide and glucose. The fluorescence spectrum of the nanovesicles suggested that curcumin was located in their bilayer region. Free-suspended nanovesicles tended to bind to the bacterial surface and demonstrated bactericidal activity toward Gram-negative (E. coli) and vegetative cells of Gram-positive (Bacillus cereus) bacteria reducing their counts from 5 log CFU mL(-1) to an undetectable level within 8 h. The nanovesicles were covalently bound to silanized glass. Incubation of E. coli and B. cereus with nanovesicle-coated glass resulted in a 2.5 log reduction in their counts. After optimization this approach can be used for controlling microbial growth, cross-contamination, and biofilm formation on food-contacting surfaces.
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Affiliation(s)
- Navneet Dogra
- College of Science, 1245 Lincoln Drive, Neckers 157A, Southern Illinois University , Carbondale Illinois 62901-4403, United States
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Makwana S, Choudhary R, Dogra N, Kohli P, Haddock J. Nanoencapsulation and immobilization of cinnamaldehyde for developing antimicrobial food packaging material. Lebensm Wiss Technol 2014. [DOI: 10.1016/j.lwt.2014.01.043] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Kohli P, Srivastava SD, Srivastava SK. Synthesis and Biological Activity of Mercaptobenzoxazole Based Thiazolidinones and Their Arylidenes. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200700144] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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22
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McNichols C, Wilkins J, Kubota A, Shiu YT, Aouadi SM, Kohli P. Investigating surface topology and cyclic-RGD peptide functionalization on vascular endothelialization. J Biomed Mater Res A 2013; 102:532-9. [PMID: 23505215 DOI: 10.1002/jbm.a.34700] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 01/13/2013] [Accepted: 01/14/2013] [Indexed: 11/09/2022]
Abstract
The advantages of endothelialization of a stent surface in comparison with the bare metal and drug-eluting stents used today include reduced late-stent restenosis and in-stent thrombosis. In this article, we study the effect of surface topology and functionalization of tantalum (Ta) with cyclic-(arginine-glycine-aspartic acid-d-phenylalanine-lysine) (cRGDfK) on the attachment, spreading, and growth of vascular endothelial cells. Self-assembled nanodimpling on Ta surfaces was performed using a one-step electropolishing technique. Next, cRGDfK was covalently bonded onto the surface using silane chemistry. Our results suggest that nanotexturing alone was sufficient to enhance cell spreading, but the combination of a nanodimpled surfaces along with the cRGDfK peptide may produce a better endothelialization coating on the surface in terms of higher cell density, better cell spreading, and more cell-cell interactions, when compared to using cRGDfK peptide functionalization alone or nanotexturing alone. We believe that future research should look into how to implement both modifications (topographic and chemical modifications) to optimize the stent surface for endothelialization.
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Affiliation(s)
- Colton McNichols
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois
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23
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Afzal AJ, Srour A, Goil A, Vasudaven S, Liu T, Samudrala R, Dogra N, Kohli P, Malakar A, Lightfoot DA. Homo-dimerization and ligand binding by the leucine-rich repeat domain at RHG1/RFS2 underlying resistance to two soybean pathogens. BMC Plant Biol 2013; 13:43. [PMID: 23497186 PMCID: PMC3626623 DOI: 10.1186/1471-2229-13-43] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 02/05/2013] [Indexed: 05/26/2023]
Abstract
BACKGROUND The protein encoded by GmRLK18-1 (Glyma_18_02680 on chromosome 18) was a receptor like kinase (RLK) encoded within the soybean (Glycine max L. Merr.) Rhg1/Rfs2 locus. The locus underlies resistance to the soybean cyst nematode (SCN) Heterodera glycines (I.) and causal agent of sudden death syndrome (SDS) Fusarium virguliforme (Aoki). Previously the leucine rich repeat (LRR) domain was expressed in Escherichia coli. RESULTS The aims here were to evaluate the LRRs ability to; homo-dimerize; bind larger proteins; and bind to small peptides. Western analysis suggested homo-dimers could form after protein extraction from roots. The purified LRR domain, from residue 131-485, was seen to form a mixture of monomers and homo-dimers in vitro. Cross-linking experiments in vitro showed the H274N region was close (<11.1 A) to the highly conserved cysteine residue C196 on the second homo-dimer subunit. Binding constants of 20-142 nM for peptides found in plant and nematode secretions were found. Effects on plant phenotypes including wilting, stem bending and resistance to infection by SCN were observed when roots were treated with 50 pM of the peptides. Far-Western analyses followed by MS showed methionine synthase and cyclophilin bound strongly to the LRR domain. A second LRR from GmRLK08-1 (Glyma_08_g11350) did not show these strong interactions. CONCLUSIONS The LRR domain of the GmRLK18-1 protein formed both a monomer and a homo-dimer. The LRR domain bound avidly to 4 different CLE peptides, a cyclophilin and a methionine synthase. The CLE peptides GmTGIF, GmCLE34, GmCLE3 and HgCLE were previously reported to be involved in root growth inhibition but here GmTGIF and HgCLE were shown to alter stem morphology and resistance to SCN. One of several models from homology and ab-initio modeling was partially validated by cross-linking. The effect of the 3 amino acid replacements present among RLK allotypes, A87V, Q115K and H274N were predicted to alter domain stability and function. Therefore, the LRR domain of GmRLK18-1 might underlie both root development and disease resistance in soybean and provide an avenue to develop new variants and ligands that might promote reduced losses to SCN.
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Affiliation(s)
- Ahmed J Afzal
- Department of Molecular Biology, Microbiology and Biochemistry and Center for Excellence the Illinois Soybean Center, Southern Illinois University at Carbondale, IL 62901, USA.
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Dogra N, Li X, Kohli P. Investigating ligand-receptor interactions at bilayer surface using electronic absorption spectroscopy and fluorescence resonance energy transfer. Langmuir 2012; 28:12989-12998. [PMID: 22734511 PMCID: PMC3439585 DOI: 10.1021/la300724z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We investigate interactions between receptors and ligands at bilayer surface of polydiacetylene (PDA) liposomal nanoparticles using changes in electronic absorption spectroscopy and fluorescence resonance energy transfer (FRET). We study the effect of mode of linkage (covalent versus noncovalent) between the receptor and liposome bilayer. We also examine the effect of size-dependent interactions between liposome and analyte through electronic absorption and FRET responses. Glucose (receptor) molecules were either covalently or noncovalently attached at the bilayer of nanoparticles, and they provided selectivity for molecular interactions between glucose and glycoprotein ligands of E. coli. These interactions induced stress on conjugated PDA chain which resulted in changes (blue to red) in the absorption spectrum of PDA. The changes in electronic absorbance also led to changes in FRET efficiency between conjugated PDA chains (acceptor) and fluorophores (Sulphorhodamine-101) (donor) attached to the bilayer surface. Interestingly, we did not find significant differences in UV-vis and FRET responses for covalently and noncovalently bound glucose to liposomes following their interactions with E. coli. We attributed these results to close proximity of glucose receptor molecules to the liposome bilayer surface such that induced stress were similar in both the cases. We also found that PDA emission from direct excitation mechanism was ~2-10 times larger than that of the FRET-based response. These differences in emission signals were attributed to three major reasons: nonspecific interactions between E. coli and liposomes, size differences between analyte and liposomes, and a much higher PDA concentration with respect to sulforhodamine (SR-101). We have proposed a model to explain our experimental observations. Our fundamental studies reported here will help in enhancing our knowledge regarding interactions involved between soft particles at molecular levels.
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25
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Dogra N, Reyes JC, Garg N, Kohli P. Real-time monitoring of ligand-receptor interactions with fluorescence resonance energy transfer. J Vis Exp 2012:e3805. [PMID: 22929922 DOI: 10.3791/3805] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
FRET is a process whereby energy is non-radiatively transferred from an excited donor molecule to a ground-state acceptor molecule through long-range dipole-dipole interactions. In the present sensing assay, we utilize an interesting property of PDA: blue-shift in the UV-Vis electronic absorption spectrum of PDA (Figure 1) after an analyte interacts with receptors attached to PDA. This shift in the PDA absorption spectrum provides changes in the spectral overlap (J) between PDA (acceptor) and rhodamine (donor) that leads to changes in the FRET efficiency. Thus, the interactions between analyte (ligand) and receptors are detected through FRET between donor fluorophores and PDA. In particular, we show the sensing of a model protein molecule streptavidin. We also demonstrate the covalent-binding of bovine serum albumin (BSA) to the liposome surface with FRET mechanism. These interactions between the bilayer liposomes and protein molecules can be sensed in real-time. The proposed method is a general method for sensing small chemical and large biochemical molecules. Since fluorescence is intrinsically more sensitive than colorimetry, the detection limit of the assay can be in sub-nanomolar range or lower. Further, PDA can act as a universal acceptor in FRET, which means that multiple sensors can be developed with PDA (acceptor) functionalized with donors and different receptors attached on the surface of PDA liposomes.
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Affiliation(s)
- Navneet Dogra
- Department of Chemistry and Biochemistry, Southern Illinois University, USA
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26
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Abstract
The ability to fabricate flexible filtration membranes that can selectively separate particles of different sizes is of considerable interest. In this article, we describe a facile, reproducible and simple one-step method to produce pores in polydimethylsiloxane (PDMS) membranes. We embedded micron-sized NaHCO(3) particles in 50 micron thick PDMS films. After curing, the membranes were immersed in concentrated HCl acid. Pores were generated in the membrane by the evolution of CO(2) gas from the reaction of NaHCO(3) and HCl. High resolution Scanning Electron Microscope images clearly reveal the presence of openings on the surface and the cross-section of the membranes. Fluorescence and back-scattered electron imaging of porous PDMS membrane with embedded gold nanoparticles and comparison with non-porous PDMS membranes provided unambiguous evidence of pores in the membrane. Transport studies of molecular fluoresceinate ions, ions (sodium and chloride) and 240 nm polystyrene nanoparticles through these membranes demonstrate passable pores and existence of channels within the body of the membrane. Mechanically stretching the porous PDMS membrane and comparing the flow rates of fluoresceinate ions and the polystyrene beads through the stretched and unstretched membranes allowed a direct proof of the modulation of transport rate in the membranes. We show that stretching the membranes by 10% increases the flow rate of fluorescein molecules by 2.8 times and by a factor of approximately ~40% for the polystyrene nanoparticles.
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Affiliation(s)
- Kexin Jiao
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901
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27
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Zhou C, Kohli P. Ultracompact beam splitters based on plasmonic nanoslits. J Appl Phys 2011; 109:93114-931146. [PMID: 21647248 PMCID: PMC3107828 DOI: 10.1063/1.3582005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Accepted: 03/09/2011] [Indexed: 05/30/2023]
Abstract
An ultracompact plasmonic beam splitter is theoretically and numerically investigated. The splitter consists of a V-shaped nanoslit in metal films. Two groups of nanoscale metallic grooves inside the slit (A) and at the small slit opening (B) are investigated. We show that there are two energy channels guiding light out by the splitter: the optical and the plasmonic channels. Groove A is used to couple incident light into the plasmonic channel. Groove B functions as a plasmonic scatter. We demonstrate that the energy transfer through plasmonic path is dominant in the beam splitter. We find that more than four times the energy is transferred by the plasmonic channel using structures A and B. We show that the plasmonic waves scattered by B can be converted into light waves. These light waves redistribute the transmitted energy through interference with the field transmitted from the nanoslit. Therefore, different beam splitting effects are achieved by simply changing the interference conditions between the scattered waves and the transmitted waves. The impact of the width and height of groove B are also investigated. It is found that the plasmonic scattering of B is changed into light scattering with increase of the width and the height of B. These devices have potential applications in optical sampling, signal processing, and integrated optical circuits.
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28
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Weaver JE, Dasari MR, Datar A, Talapatra S, Kohli P. Investigating photoinduced charge transfer in carbon nanotube-perylene-quantum dot hybrid nanocomposites. ACS Nano 2010; 4:6883-6893. [PMID: 20945933 DOI: 10.1021/nn1020067] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this study, we investigate photophysical and photoinduced current responses of a nanocomposite which consists of multiwalled carbon nanotubes (CNTs), thiol derivative perylene compound (ETPTCDI), and cadmium selenide quantum dots (QDs). These QDs as well as the ETPTCDI harvest photons and transfer their excited electrons or holes to CNTs to complete the circuit. Both QDs and ETPTCDI contribute charges to the carbon nanotubes, which increased the overall photon harvest efficiency of the nanocomposite. Herein, we investigate through a series of photophysical photoluminescence quenching studies the charge transfer between donors (QDs and ETPTCDI) and acceptor (CNTs). The incorporation of ETPTCDI into the nanocomposite significantly increases the adhesion between QDs and CNTs through bonding between QDs and thiol groups on ETPTCDI and π-π interactions between ETPTCDI and CNTs. Thus, ETPTCDI acted as a molecular linker between QDs and CNTs. Furthermore, a significant increase (>5 times) in the Stern-Volmer constant, K(sv), for QD emission after addition of ETPTCDI-tagged CNTs clearly indicates a large enhancement in the adhesion between CNTs and QDs. The nanocomposite shows a ∼2-4-fold increase in the photoconductivity when exposed to AM1.5 solar-simulated light. The damage to the nanocomposite from the intensity of the solar-simulated light is also investigated. The proposed nanocomposite has the potential for photovoltaic applications such as being the active component in a hybrid bulk heterojunction solar cell.
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Affiliation(s)
- Joseph E Weaver
- Department of Chemistry & Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, United States
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Abstract
We demonstrate conical pores etched in tracked glass chips for fabricating patterns at the micrometer scale. Highly fluorescent patterns based on photopolymerization of diacetylene films were formed by irradiating UV light through conical pores called "photo-pens". The properties of photopens were investigated through experiments, finite-difference-time-domain (FDTD) simulations and numerical calculations based on Fresnel equations. We show that the pattern dimensions are easily controlled by adjusting the exposure time. Thus, patterns with a range of dimensions can be fabricated without any need of changes in the pore diameter. Parallel patterning was also demonstrated by simultaneously exposing the films to photons through multiple pores in the chip. Our method provides an inexpensive, versatile, and efficient way for patterning without the use of sophisticated masks.
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Affiliation(s)
- Chuanhong Zhou
- Department of Chemistry & Biochemistry, Southern Illinois University, Carbondale, IL 62901
| | | | - Justin Wolff
- Department of Chemistry & Biochemistry, Southern Illinois University, Carbondale, IL 62901
| | - Xuelian Li
- Department of Chemistry & Biochemistry, Southern Illinois University, Carbondale, IL 62901
| | - Punit Kohli
- Department of Chemistry & Biochemistry, Southern Illinois University, Carbondale, IL 62901
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30
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Zhang X, Luster B, Church A, Muratore C, Voevodin AA, Kohli P, Aouadi S, Talapatra S. Carbon nanotube-MoS2 composites as solid lubricants. ACS Appl Mater Interfaces 2009; 1:735-9. [PMID: 20355996 DOI: 10.1021/am800240e] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Solid lubricants (SLs) characterized by low coefficients of friction (mu) and wear rates (w) drastically improve the life span of instruments that undergo extreme frictional wear. However, the performance of SLs such as sputtered or nanoparticulate molybdenum disulfide (MoS(2)), tungsten disulfide (WS(2)), or graphite deteriorates heavily under extreme operational conditions such as elevated temperatures and high humidity. Here, we present our preliminary results, which demonstrate that composites of carbon nanotubes (CNTs) and MoS(2) produced by electrodeposition of MoS(2) on vertically aligned CNT films have low mu ( approximately 0.03) and w (approximately 10(-13) mm(3)/N.mm) even at 300 degrees C, which are about 2 orders of magnitude better than those of nanoparticulate MoS(2)-based coatings. The high load-bearing capacity of CNTs provides a strong enduring support to MoS(2) nanoclusters and is responsible for their ultralow w. The incorporation of these composites in liquid lubricants reduces the friction coefficient of the liquid lubricants by approximately 15%. The technique described here to produce SL coatings with extremely appealing frictional properties will provide valuable solutions for a variety of tribological applications where the coatings encounter high temperature, reduced pressure, and/or low- and high-humidity conditions.
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Affiliation(s)
- Xianfeng Zhang
- Department of Physics, Southern Illinois University-Carbondale, Carbondale, IL 62901, USA
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31
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Abstract
In this study, we demonstrate a facile and simple synthesis of quantum dot (QD)-polymer composites. Highly fluorescent semiconducting CdSe/ZnS quantum dots were embedded in different commercially available polymers using one easy step. QD-polymer composite nanoparticles were also synthesized using template-assisted synthesis. In particular, we self-assembled lamellar micelles inside nanoporous alumina membranes which were used for the synthesis of mesoporous silica hollow nanotubes and solid nanorods. We observed that the addition of excess free octadecylamine (ODA) in the QD-silica solution resulted in gelation. The gelation time was found to be dependent on free ODA concentration. Similarly, the emission of QD-polymer composites was also found to be dependent on free ODA concentration. Highly purified QDs provided polymer composites that have a much lower emission compared to unpurified nanocomposites. This was attributed to passivation of the QD surfaces by amine, which reduced the surface defects and non-radiative pathways for excited QDs. Finally, highly fluorescent QD-polymer patterns were demonstrated on glass substrates which retained their emission in both polar and non-polar solvents.
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Affiliation(s)
- Joe Weaver
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL, 62901, USA
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32
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Loh OY, Ho AM, Rim JE, Kohli P, Patankar NA, Espinosa HD. Electric field-induced direct delivery of proteins by a nanofountain probe. Proc Natl Acad Sci U S A 2008; 105:16438-43. [PMID: 18946047 PMCID: PMC2575438 DOI: 10.1073/pnas.0806651105] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2008] [Indexed: 11/18/2022] Open
Abstract
We report nanofabrication of protein dot and line patterns using a nanofountain atomic force microscopy probe (NFP). Biomolecules are continuously fed in solution through an integrated microfluidic system, and deposited directly onto a substrate. Deposition is controlled by application of an electric potential of appropriate sign and magnitude between the probe reservoir and substrate. Submicron dot and line molecular patterns were generated with resolution that depended on the magnitude of the applied voltage, dwell time, and writing speed. By using an energetic argument and a Kelvin condensation model, the quasi-equilibrium liquid-air interface at the probe tip was determined. The analysis revealed the origin of the need for electric fields in achieving protein transport to the substrate and confirmed experimental observations suggesting that pattern resolution is controlled by tip sharpness and not overall probe aperture. As such, the NFP combines the high-resolution of dip-pen nanolithography with the efficient continuous liquid feeding of micropipettes while allowing scalability to 1- and 2D probe arrays for high throughput.
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Affiliation(s)
- Owen Y. Loh
- Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208; and
| | - Andrea M. Ho
- Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208; and
| | - Jee E. Rim
- Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208; and
| | - Punit Kohli
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901
| | - Neelesh A. Patankar
- Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208; and
| | - Horacio D. Espinosa
- Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208; and
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33
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Gatebe E, Herron H, Zakeri R, Ramiah Rajasekaran P, Aouadi S, Kohli P. Synthesis and characterization of polydiacetylene films and nanotubes. Langmuir 2008; 24:11947-54. [PMID: 18823090 PMCID: PMC2683165 DOI: 10.1021/la801948z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We report here the synthesis and characterization of polydiacetylene (PDA) films and nanotubes using layer-by-layer (LBL) chemistry. 10,12-Docosadiyndioic acid (DCDA) monomer was self-assembled on flat surfaces and inside of nanoporous alumina templates. UV irradiation of DCDA provided polymerized-DCDA (PDCDA) films and nanotubes. We have used zirconium-carboxylate interlayer chemistry to synthesize PDCDA multilayers on flat surfaces and in nanoporous template. PDCDA multilayers were characterized using optical (UV-vis, fluorescence, ellipsometry, FTIR) spectroscopies, ionic current-voltage ( I- V) analysis, and scanning electron microscopy. Ellipsometry, FTIR, electronic absorption and emission spectroscopies showed a uniform DCDA deposition at each deposition cycle. Our optical spectroscopic analysis indicates that carboxylate-zirconium interlinking chemistry is robust. To explain the disorganization in the alkyl portion of PDCDA multilayer films, we propose carboxylate-zirconium interlinkages act as "locks" in between PDCDA layers which restrict the movement of alkyl portion in the films. Because of this locking, the induced-stresses in the polymer chains can not be efficiently relieved. Our ionic resistance data from I- V analysis correlate well with calculated resistance at smaller number of PDCDA layers but significantly deviated for thicker PDCDA nanotubes. These differences were attributed to ion-blocking because some of the PDCDA nanotubes were totally closed and the nonohmic and permselective ionic behaviors when the diameter of the pores approaches the double-layer thickness of the solution inside of the nanotubes.
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Affiliation(s)
- Erastus Gatebe
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, USA.
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34
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Abstract
Conjugated polydiacetylene (PDA) possessing stimuli-responsive properties has been intensively investigated for developing efficient sensors. We report here fluorescence resonance energy transfer (FRET) in liposomes synthesized using different molar ratios of dansyl-tagged diacetylene and diacetylene-carboxylic acid monomers. Photopolymerization of diacetylene resulted in cross-linked PDA liposomes. We used steady-state electronic absorption, emission, and fluorescence anisotropy (FA) analysis to characterize the thermal-induced FRET between dansyl fluorophores (donor) and PDA (acceptor). We found that the monomer ratio of acceptor to donor ( R ad) and length of linkers (functional part that connects dansyl fluorophores to the diacetylene group in the monomer) strongly affected FRET. For R ad = 10 000, the acceptor emission intensity was amplified by more than 18 times when the liposome solution was heated from 298 to 338 K. A decrease in R ad resulted in diminished acceptor emission amplification. This was primarily attributed to lower FRET efficiency between donors and acceptors and a higher background signal. We also found that the FRET amplification of PDA emissions after heating the solution was much higher when dansyl was linked to diacetylene through longer and flexible linkers than through shorter linkers. We attributed this to insertion of dansyl in the bilayer of the liposomes, which led to an increased dansyl quantum yield and a higher interaction of multiple acceptors with limited available donors. This was not the case for shorter and more rigid linkers where PDA amplification was much smaller. The present studies aim at enhancing our understanding of FRET between fluorophores and PDA-based conjugated liposomes. Furthermore, receptor tagged onto PDA liposomes can interact with ligands present on proteins, enzymes, and cells, which will produce emission sensing signal. Therefore, using the present approach, there exist opportunities for designing FRET-based highly sensitive and selective chemical and biochemical sensors.
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Affiliation(s)
- Xuelian Li
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, USA
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35
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Kertzman Z, Marchal J, Suarez M, Staia MH, Filip P, Kohli P, Aouadi SM. Mechanical, tribological, and biocompatibility properties of ZrN-Ag nanocomposite films. J Biomed Mater Res A 2008; 84:1061-7. [PMID: 17685406 DOI: 10.1002/jbm.a.31533] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Nanocomposite films of ZrN-Ag were produced by reactive unbalanced magnetron sputtering, and their structural, chemical, mechanical, tribological, haemocompatibility, and antibacterial properties were studied as a function of film composition. The films formed a dense and homogeneous microstructure whereby nanocrystals of Ag are distributed evenly throughout the ZrN matrix. For small additions of silver, the hardness was found to increase, whereas the elastic modulus was found to decrease drastically. In the process of optimizing the deposition conditions, three kinds of coatings were prepared on 316 L surgical steel and tested by accelerated electrochemical polarization tests in order to detect the influence of Ag and the value of the bias potential on the corrosion performance of the system. Films produced under the optimum deposition conditions were, subsequently, deposited on medical grade Ti-Al-V and worn against ball-bearing steel using a ball-on-disk tribotester in bovine serum and were found to have superior tribological properties compared with single-phase ZrN coatings. The haemocompatibility of the films was assessed by investigating the adsorption of human serum albumin and fibrinogen on samples with different phase compositions. Quantification of the protein adsorption was carried out using spectroscopic ellipsometry, which confirmed the haemocompatibility of the films. Antibiotic activity of the films was quantified by incubating the films in bacterial cultures, namely, Staphylococcus epidermis, Staphylococcus aureus, and Escherichia coli. Films with a silver content > 10% exhibited superior antibacterial activity compared with the uncoated samples.
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Affiliation(s)
- Z Kertzman
- Department of Physics, Southern Illinois University, Carbondale, Illinois 62901, USA
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36
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Affiliation(s)
- Fatih Buyukserin
- Department of Chemistry and Center for Research at the Bio/Nano Interface, University of Florida, Gainesville, FL 32611-7200, USA
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37
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Abstract
We report here a novel system where the rate of energy transfer is based on changes in the spectral overlap between the emission of the donor and the absorption of the acceptor (J) as well as changes in the quantum yield of the acceptor. We use the fluorophore dansyl as the donor and polydiacetylene (PDA) as the acceptor to demonstrate the modulation of FRET through conformationally induced changes in the PDA absorption spectrum following thermal treatment that converts the PDA backbone of the liposome from the blue form to the red form. Energy transfer was found to be significantly more efficient from dansyl to the red-form PDA. These findings support the basis of a new sensing platform that utilizes J-modulated FRET as an actuating mechanism.
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Affiliation(s)
- Xuelian Li
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, USA
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38
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Bliss TM, Kelly S, Shah AK, Foo WC, Kohli P, Stokes C, Sun GH, Ma M, Masel J, Kleppner SR, Schallert T, Palmer T, Steinberg GK. Transplantation of hNT neurons into the ischemic cortex: Cell survival and effect on sensorimotor behavior. J Neurosci Res 2006; 83:1004-14. [PMID: 16496370 DOI: 10.1002/jnr.20800] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cell transplantation offers a potential new treatment for stroke. Animal studies using models that produce ischemic damage in both the striatum and the frontal cortex have shown beneficial effects when hNT cells (postmitotic immature neurons) were transplanted into the ischemic striatum. In this study, we investigated the effect of hNT cells in a model of stroke in which the striatum remains intact and damage is restricted to the cortex. hNT cells were transplanted into the ischemic cortex 1 week after stroke induced by distal middle cerebral artery occlusion (dMCAo). The cells exhibited robust survival at 4 weeks posttransplant even at the lesion border. hNT cells did not migrate, but they did extend long neurites into the surrounding parenchyma mainly through the white matter. Neurite extension was predominantly toward the lesion in ischemic animals but was bidirectional in uninjured animals. Extension of neurites through the cortex toward the lesion was also seen when there was some surviving cortical tissue between the graft and the infarct. Prolonged deficits were obtained in four tests of sensory-motor function. hNT-transplanted animals showed a significant improvement in functional recovery on one motor test, but there was no effect on the other three tests relative to control animals. Thus, despite clear evidence of graft survival and neurite extension, the functional benefit of hNT cells after ischemia is not guaranteed. Functional benefit could depend on other variables, such as infarct location, whether the cells mature, the behavioral tests employed, rehabilitation training, or as yet unidentified factors.
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Affiliation(s)
- T M Bliss
- Department of Neurosurgery, Stanford University, Stanford, California, USA.
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39
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Abstract
There is increasing interest in the concept of using nanopores as the sensing elements in biosensors. The nanopore most often used is the alpha-hemolysin protein channel, and the sensor consists of a single channel embedded within a lipid bilayer membrane. An ionic current is passed through the channel, and analyte species are detected as transient blocks in this current associated with translocation of the analyte through the channel-stochastic sensing. While this is an extremely promising sensing paradigm, it would be advantageous to eliminate the very fragile lipid bilayer membrane and perhaps to replace the biological nanopore with an abiotic equivalent. We describe here a new family of protein biosensors that are based on conically shaped gold nanotubes embedded within a mechanical and chemically robust polymeric membrane. While these sensors also function by passing an ion current through the nanotube, the sensing paradigm is different from the previous devices in that a transient change in the current is not observed. Instead, the protein analyte binds to a biochemical molecular-recognition agent at the mouth of the conical nanotube, resulting in complete blockage of the ion current. Three different molecular-recognition agents, and correspondingly three different protein analytes, were investigated: (i) biotin/streptavidin, (ii) protein-G/immunoglobulin, and (iii) an antibody to the protein ricin with ricin as the analyte.
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Affiliation(s)
- Zuzanna Siwy
- Department of Chemistry and Center for Research at the Bio/Nano Interface, University of Florida, Gainesville, Florida 32611-7200, USA
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40
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Abstract
Nanotechnology concerns the science of very small particles and deals with both the fundamental aspects of understanding the properties of such nanoparticles and with developing technological applications of nanoparticles. Biomedical and biotechnological applications of nanoparticles have been of special recent research and development interest, with potential applications that include use of nanoparticles as drug (or DNA) delivery vehicles, and as components in medical diagnostic kits, biosensors and membranes for bioseparations. Spherical nanoparticles are typically used for such applications, but this only reflects the fact that spheres are easier to make than nanoparticles having other shapes. Micro and nanotubes - structures that resemble tiny drinking straws - are alternatives and may offer advantages over spherical nanoparticles for some applications. This article discusses different approaches for making micro and nanotubes and reviews the current status of efforts to develop biomedical and biotechnological applications of these tubular structures.
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Affiliation(s)
- Punit Kohli
- Department of Chemistry and Center for Research at Bio/Nano Interface, University of Florida, Gainesville, FL 32611, USA
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41
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42
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Abstract
There is considerable interest in developing chemical devices that mimic the function of biological ion channels. We recently described such a device, which consisted of a single conically shaped gold nanotube embedded within a polymeric membrane. This device mimicked one of the key functions of voltage-gated ion channels: the ability to strongly rectify the ionic current flowing through it. The data obtained were interpreted using a simple electrostatic model. While the details are still being debated, it is clear that ion-current-rectification in biological ion channels is more complicated and involves physical movement of an ionically charged portion of the channel in response to a change in the transmembrane potential. We report here artificial ion channels that rectify the ion current flowing through them via this "electromechanical" mechanism. These artificial channels are also based on conical gold nanotubes, but with the critical electromechanical response provided by single-stranded DNA molecules attached to the nanotube walls.
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Affiliation(s)
- C Chad Harrell
- Department of Chemistry and Center for Research at the Bio/Nano Interface, University of Florida, Gainesville, Florida 32611-7200, USA
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43
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Abstract
Ion channels are protein pores that span cell membranes and open and close in response to stimuli like changes in the transmembrane potential, binding of a ligand, or mechanical stress. When open, ions pass through the pore, and hence across the cell membrane, and when closed, ion-transport is precluded. Hence, these channels are nanodevices that have a current-rectification function. There is intense research effort aimed at understanding the molecular-level mechanism for this function. One approach for elucidating the mechanism is to construct a simple abiotic system that mimics this function and to use the mechanistic details of this mimic as a guide to understand the more complex biological channel. We describe here such an abiotic mimic: a synthetic membrane that contains a single conical gold nanotube. The advantage of this mimic is that the surface charge and chemistry of the nanotube wall can be varied, at will, by judicious choice of electrolyte or by thiol chemisorption. This has allowed us to make conical Au nanotubes that rectify the ion current and, just as importantly, to definitively elucidate the mechanism of this function.
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Affiliation(s)
- Zuzanna Siwy
- Department of Chemistry, Center for Research at the Bio/Nano Interface, University of Florida, Gainesville, FL 32611-7200, USA
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44
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Abstract
We describe synthetic membranes in which the molecular recognition chemistry used to accomplish selective permeation is DNA hybridization. These membranes contain template-synthesized gold nanotubes with inside diameters of 12 nanometers, and a "transporter" DNA-hairpin molecule is attached to the inside walls of these nanotubes. These DNA-functionalized nanotube membranes selectively recognize and transport the DNA strand that is complementary to the transporter strand, relative to DNA strands that are not complementary to the transporter. Under optimal conditions, single-base mismatch transport selectivity can be obtained.
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Affiliation(s)
- Punit Kohli
- Department of Chemistry and Center for Research at the Bio/Nano Interface, University of Florida, Gainesville, FL 32611-7200, USA
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45
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Abstract
Nanotube-containing membranes prepared by the template method show promise for use as highly selective filters for membrane-based chemical and biological separations. Most of the work to date has been done on gold nanotubes prepared by electroless deposition of Au within the pores of polymeric filtration membranes. These polymeric filters have very low porosities (< 1%), and, as a result, the flux through Au nanotube membranes based on these templates is very low. In contrast, the other popular template membranes-anodic aluminas-have high porosities-30% to 50%. In spite of this potential advantage of anodic alumina templates, there have been no reports of electrolessly plated Au nanotubes within the pores of these templates. This is because the electroless plating method used to deposit Au nanotubes in polymeric templates does not work in aluminas. We have developed a modified electroless plating strategy that can be used to deposit high-quality Au nanotubes within the pores of the alumina templates. We describe this new plating method here.
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Affiliation(s)
- Punit Kohli
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA
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46
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Abstract
Nanoparticles are being developed for a host of biomedical and biotechnological applications including drug delivery, enzyme immobilization and DNA transfection. Spherical nanoparticles are typically used for such applications, but this only reflects the fact that spheres are easier to make than other shapes. Micro- and nanotubes--structures that resemble tiny drinking straws--are alternatives and may offer advantages over spherical nanoparticles for some applications. This article discusses four different approaches to making micro- and nanotubes and reviews the current status of efforts to develop biomedical and biotechnological applications of these tubular structures.
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Affiliation(s)
- Punit Kohli
- Department of Chemistry and Center for Research at the Bio/Nano Interface, University of Florida, Gainesville, Florida 32611-7200, USA.
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47
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Abstract
Electroless deposition of gold on the pore walls of polycarbonate templates is currently the best known method for controlling inside diameters of template-synthesized nanotubes. It would be very useful to have alternative template-based synthetic chemistries that yield nanotubes composed of other materials, but which still allow for precise control over the nanotube wall thickness and i.d. A film-formation process that is based on layer-by-layer deposition of the film-forming material along the pore walls of the template membrane provides this desired alternative synthetic chemistry. We describe here the use of Mallouk's alpha,omega-diorganophosphonate/Zr layer-by-layer film-forming method for preparing nanotubes within the pores of alumina template membranes. We have found that this method allows accurate, quantitative, and predictable control over the wall thickness, and thus i.d., of the layered nanotubes obtained.
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Affiliation(s)
- Shifeng Hou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA
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48
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Chatterjee A, Das D, Kohli P, Das R, Kohli V. Awareness of infective endocarditis prophylaxis and dental hygiene in cardiac patients after physician contact. Indian J Pediatr 2004; 71:184. [PMID: 15053389 DOI: 10.1007/bf02723109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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49
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50
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Abstract
Nanoparticles are being developed for a host of biomedical and biotechnological applications, including drug delivery, enzyme immobilization and DNA transfection. Spherical nanoparticles are typically used for such applications, which reflects the fact that spheres are easier to make than other shapes. Micro- and nanotubes--structures that resemble tiny drinking straws--are alternatives that might offer advantages over spherical nanoparticles for some applications. This article discusses four approaches for making micro- and nanotubes, and reviews the current status of efforts to develop biomedical and biotechnological applications of these tubular structures.
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Affiliation(s)
- Charles R Martin
- Department of Chemistry and Center for Research at the Bio/Nano Interface, University of Florida, Gainesville, Florida 32611-7200, USA.
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