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Kamranikia K, Dominici S, Keller M, Kube N, Mougin K, Spangenberg A. Very High-Aspect-Ratio Polymeric Micropillars Made by Two-Photon Polymerization. MICROMACHINES 2023; 14:1602. [PMID: 37630138 PMCID: PMC10456646 DOI: 10.3390/mi14081602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/02/2023] [Accepted: 08/13/2023] [Indexed: 08/27/2023]
Abstract
Polymeric micropillars with a high-aspect-ratio (HAR) are of interest for a wide range of applications, including drug delivery and the micro-electro-mechanical field. While molding is the most common method for fabricating HAR microstructures, it is affected by challenges related to demolding the final structure. In this study, we present very HAR micropillars using two-photon polymerization (TPP), an established technique for creating complex 3D microstructures. Polymeric micropillars with HARs fabricated by TPP often shrink and collapse during the development process. This is due to the lack of mechanical stability of micropillars against capillary forces primarily acting during the fabrication process when the solvent evaporates. Here, we report different parameters that have been optimized to overcome the capillary force. These include surface modification of the substrate, fabrication parameters such as laser power, exposure time, the pitch distance between the pillars, and the length of the pillars. On account of adopting these techniques, we were able to fabricate micropillars with a very HAR up to 80.
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Affiliation(s)
- Keynaz Kamranikia
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France; (K.K.); (S.D.); (M.K.); (N.K.); (K.M.)
- Université de Strasbourg, 67000 Strasbourg, France
| | - Sébastien Dominici
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France; (K.K.); (S.D.); (M.K.); (N.K.); (K.M.)
- Université de Strasbourg, 67000 Strasbourg, France
| | - Marc Keller
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France; (K.K.); (S.D.); (M.K.); (N.K.); (K.M.)
- Université de Strasbourg, 67000 Strasbourg, France
| | - Niklas Kube
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France; (K.K.); (S.D.); (M.K.); (N.K.); (K.M.)
- Université de Strasbourg, 67000 Strasbourg, France
| | - Karine Mougin
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France; (K.K.); (S.D.); (M.K.); (N.K.); (K.M.)
- Université de Strasbourg, 67000 Strasbourg, France
| | - Arnaud Spangenberg
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France; (K.K.); (S.D.); (M.K.); (N.K.); (K.M.)
- Université de Strasbourg, 67000 Strasbourg, France
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Khurram R, Wang Z, Ehsan MF, Peng S, Shafiq M, Khan B. Synthesis and characterization of an α-Fe 2O 3/ZnTe heterostructure for photocatalytic degradation of Congo red, methyl orange and methylene blue. RSC Adv 2020; 10:44997-45007. [PMID: 35516253 PMCID: PMC9058815 DOI: 10.1039/d0ra06866g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 11/16/2020] [Indexed: 12/12/2022] Open
Abstract
The leading challenge towards environmental protection is untreated textile dyes. Tailoring photocatalytic materials is one of the sustainable remediation strategies for dye treatment. Hematite (α-Fe2O3), due to its favorable visible light active band gap (i.e. 2.1 eV), has turned out to be a robust material of interest. However, impoverished photocatalytic efficiency of α-Fe2O3 is ascribable to the short life span of the charge carriers. Consequently, the former synthesized heterostructures possess low degradation efficiency. The aim of the proposed endeavor is the synthesis of a novel zinc telluride-modified hematite (α-Fe2O3/ZnTe) heterostructure, its characterization and demonstration of its enhanced photocatalytic response. The promising heterostructure as well as bare photocatalysts were synthesized via a hydrothermal approach. All photocatalysts were characterized by the X-ray diffraction technique (XRD), scanning electron microscopy (SEM), and electron diffraction spectroscopy (EDX). Moreover, the selectivity and activity of the photocatalyst are closely related to the alignment of its band energy levels, which were estimated by UV-Vis diffuse reflectance spectroscopy (DRS) and X-ray photoelectron spectroscopy (XPS). Nanomaterials, specifically α-Fe2O3 and α-Fe2O3/ZnTe, were used for the degradation of Congo red (97.9%), methyl orange (84%) and methylene blue (73%) under light irradiation (>200 nm) for 60 min. The results suggested that with the aforementioned optimized fabricated heterostructure, the degradation efficiency was improved in comparison to bare hematite (α-Fe2O3). The key rationale towards such improved photocatalytic response is the establishment of a type-II configuration in the α-Fe2O3/ZnTe heterostructure.
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Affiliation(s)
- Rooha Khurram
- Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology Beijing China +86-10-6739-1983 +86-10-6739-6186
- Department of Chemistry, School of Natural Sciences (SNS), NUST H-12 Islamabad Pakistan
| | - Zhan Wang
- Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology Beijing China +86-10-6739-1983 +86-10-6739-6186
| | - Muhammad Fahad Ehsan
- Department of Chemistry, School of Natural Sciences (SNS), NUST H-12 Islamabad Pakistan
- Department of Chemistry, Cape Breton University 1250 Grand Lake Road Sydney NS B1P 6L2 Canada
| | - Song Peng
- Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology Beijing China +86-10-6739-1983 +86-10-6739-6186
| | - Maryam Shafiq
- Department of Chemistry, School of Natural Sciences (SNS), NUST H-12 Islamabad Pakistan
| | - Bushra Khan
- Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology Beijing China +86-10-6739-1983 +86-10-6739-6186
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Higgins SG, Becce M, Belessiotis-Richards A, Seong H, Sero JE, Stevens MM. High-Aspect-Ratio Nanostructured Surfaces as Biological Metamaterials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1903862. [PMID: 31944430 PMCID: PMC7610849 DOI: 10.1002/adma.201903862] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 10/02/2019] [Indexed: 04/14/2023]
Abstract
Materials patterned with high-aspect-ratio nanostructures have features on similar length scales to cellular components. These surfaces are an extreme topography on the cellular level and have become useful tools for perturbing and sensing the cellular environment. Motivation comes from the ability of high-aspect-ratio nanostructures to deliver cargoes into cells and tissues, access the intracellular environment, and control cell behavior. These structures directly perturb cells' ability to sense and respond to external forces, influencing cell fate, and enabling new mechanistic studies. Through careful design of their nanoscale structure, these systems act as biological metamaterials, eliciting unusual biological responses. While predominantly used to interface eukaryotic cells, there is growing interest in nonanimal and prokaryotic cell interfacing. Both experimental and theoretical studies have attempted to develop a mechanistic understanding for the observed behaviors, predominantly focusing on the cell-nanostructure interface. This review considers how high-aspect-ratio nanostructured surfaces are used to both stimulate and sense biological systems.
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Affiliation(s)
- Stuart G. Higgins
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | | | | | - Hyejeong Seong
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | - Julia E. Sero
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | - Molly M. Stevens
- Department of Materials, Imperial College London, London, SW7 2AZ, UK
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
- Institute of Biomedical Engineering, Imperial College London, London, SW7 2AZ, UK
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Abstract
Despite emerging breakthroughs in the achievement of numerous elegant biomimetic structures that impart fascinating functionalities, bioinspired materials still suffer from poor structural durability, chemical reliability, flexibility, and optical transparency, as well as unaffordable cost and low throughput, thus preventing their broad real-life applications. In striking contrast to conventional wisdom, we demonstrate that the usually avoided and detrimental elastic crack phenomenon can be translated into powerful configurable-crack engineering to achieve structures and functions that are impossible to realize even using state-of-the-art techniques. Our approach dramatically enriches the freedom and flexibility in the design of materials to mimic various natural living organisms and paves the road for translating nature’s inspirations into real-world applications. Three-dimensional hierarchical morphologies widely exist in natural and biomimetic materials, which impart preferential functions including liquid and mass transport, energy conversion, and signal transmission for various applications. While notable progress has been made in the design and manufacturing of various hierarchical materials, the state-of-the-art approaches suffer from limited materials selection, high costs, as well as low processing throughput. Herein, by harnessing the configurable elastic crack engineering—controlled formation and configuration of cracks in elastic materials—an effect normally avoided in various industrial processes, we report the development of a facile and powerful technique that enables the faithful transfer of arbitrary hierarchical structures with broad material compatibility and structural and functional integrity. Our work paves the way for the cost-effective, large-scale production of a variety of flexible, inexpensive, and transparent 3D hierarchical and biomimetic materials.
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Dulay MT, Zaman N, Jaramillo D, Mody AC, Zare RN. Pathogen-Imprinted Organosiloxane Polymers as Selective Biosensors for the Detection of Targeted E. coli. C 2018; 4:29. [PMID: 33381537 PMCID: PMC7743956 DOI: 10.3390/c4020029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 04/04/2018] [Indexed: 12/12/2022]
Abstract
Early detection of pathogens requires methods that are fast, selective, sensitive and affordable. We report the development of a biosensor with high sensitivity and selectivity based on the low-cost preparation of organosiloxane (OSX) polymers imprinted with E. coli-GFP (green fluorescent protein). OSX polymers with high optical transparency, no cracking, and no shrinkage were prepared by varying several parameters of the sol-gel reaction. The unique shape and chemical fingerprint of the targeted inactivated E. coli-GFP were imprinted into bulk polymers by replication imprinting where the polymer solution was dropcast onto a bacteria template that produced a replica of the bacterial shape and chemistry on the polymer surface upon removal of the template. Capture performances were studied under non-laminar flow conditions with samples containing inactivated E. coli-GFP and compared to inactivated S. typhimurium-GFP. Capture selectivity ratios are dependent on the type of alkoxysilanes used, the H2O:silane molar ratio, and the polymerization temperature. The bacteria concentration in suspension ranged from ~6 × 105 to 1.6 × 109 cells/mL. E. coli-imprinted OSX polymers with polyethylene glycol (PEG) differentiated between the targeted bacterium E. coli, and non-targeted bacteria S. typhimurium and native E. coli-GFP, achieving selectivity ratios up to 4.5 times higher than polydimethylsiloxane (PDMS) and OSX polymers without PEG.
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Affiliation(s)
- Maria T Dulay
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA; (M.T.D.); (N.Z.); (D.J.); (A.C.M.)
| | - Naina Zaman
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA; (M.T.D.); (N.Z.); (D.J.); (A.C.M.)
| | - David Jaramillo
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA; (M.T.D.); (N.Z.); (D.J.); (A.C.M.)
| | - Alison C Mody
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA; (M.T.D.); (N.Z.); (D.J.); (A.C.M.)
| | - Richard N Zare
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA; (M.T.D.); (N.Z.); (D.J.); (A.C.M.)
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Liao C, Anderson W, Antaw F, Trau M. Maskless 3D Ablation of Precise Microhole Structures in Plastics Using Femtosecond Laser Pulses. ACS APPLIED MATERIALS & INTERFACES 2018; 10:4315-4323. [PMID: 29313352 DOI: 10.1021/acsami.7b18029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Femtosecond laser ablation is a robust tool for the fabrication of microhole structures. This technique has several advantages compared to other microfabrication strategies for reliably preparing microhole structures of high quality and low cost. However, few studies have explored the use of femtosecond laser ablation in plastic materials because of the lack of controllability over the fabrication process in plastics. In particular, the depth profile of microhole structures prepared by conventional laser ablation techniques in plastics cannot be precisely and reproducibly controlled. In this paper, a novel three-dimensional femtosecond laser ablation technique was developed for the rapid fabrication of precise microhole structures in multiple plastics in air. Using a three-step fabrication scheme, microholes demonstrated extremely clean and sharp geometric features. This new technique also enables the precise creation of arbitrary-shaped microwell structures in plastic substrates through a rapid single-step ablation process, without the need for any masks. As a proof of concept for practical applications, precise microhole structures prepared by this novel femtosecond laser ablation technique were exploited for robust resistive-pulse sensing of microparticles.
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Affiliation(s)
- Caizhi Liao
- Centre for Personalized Nanomedicine, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland , Corner College and Cooper Roads (Bldg 75), Brisbane, Queensland 4072, Australia
| | - Will Anderson
- Centre for Personalized Nanomedicine, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland , Corner College and Cooper Roads (Bldg 75), Brisbane, Queensland 4072, Australia
| | - Fiach Antaw
- Centre for Personalized Nanomedicine, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland , Corner College and Cooper Roads (Bldg 75), Brisbane, Queensland 4072, Australia
| | - Matt Trau
- Centre for Personalized Nanomedicine, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland , Corner College and Cooper Roads (Bldg 75), Brisbane, Queensland 4072, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland , Brisbane, Queensland 4072, Australia
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Pensabene V, Costa L, Terekhov A, Gnecco JS, Wikswo J, Hofmeister W. Ultrathin Polymer Membranes with Patterned, Micrometric Pores for Organs-on-Chips. ACS APPLIED MATERIALS & INTERFACES 2016; 8:22629-36. [PMID: 27513606 PMCID: PMC5131702 DOI: 10.1021/acsami.6b05754] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The basal lamina or basement membrane (BM) is a key physiological system that participates in physicochemical signaling between tissue types. Its formation and function are essential in tissue maintenance, growth, angiogenesis, disease progression, and immunology. In vitro models of the BM (e.g., Boyden and transwell chambers) are common in cell biology and lab-on-a-chip devices where cells require apical and basolateral polarization. Extravasation, intravasation, membrane transport of chemokines, cytokines, chemotaxis of cells, and other key functions are routinely studied in these models. The goal of the present study was to integrate a semipermeable ultrathin polymer membrane with precisely positioned pores of 2 μm diameter in a microfluidic device with apical and basolateral chambers. We selected poly(l-lactic acid) (PLLA), a transparent biocompatible polymer, to prepare the semipermeable ultrathin membranes. The pores were generated by pattern transfer using a three-step method coupling femtosecond laser machining, polymer replication, and spin coating. Each step of the fabrication process was characterized by scanning electron microscopy to investigate reliability of the process and fidelity of pattern transfer. In order to evaluate the compatibility of the fabrication method with organs-on-a-chip technology, porous PLLA membranes were embedded in polydimethylsiloxane (PDMS) microfluidic devices and used to grow human umbilical vein endothelial cells (HUVECS) on top of the membrane with perfusion through the basolateral chamber. Viability of cells, optical transparency of membranes and strong adhesion of PLLA to PDMS were observed, thus confirming the suitability of the prepared membranes for use in organs-on-a-chip devices.
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Affiliation(s)
- Virginia Pensabene
- Department of Biomedical Engineering; Vanderbilt University, Nashville, TN 37235 USA
- School of Electronic and Electrical Engineering, University of Leeds, Leeds, LS2 9JT, UK
- School of Medicine, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, LS9 7TF, UK
| | - Lino Costa
- Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, TN 37388 USA
| | - Alexander Terekhov
- Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, TN 37388 USA
| | - Juan S. Gnecco
- Department of Cellular and Molecular Pathology, Vanderbilt University, Nashville, TN 37235 USA
| | - John Wikswo
- Department of Biomedical Engineering; Vanderbilt University, Nashville, TN 37235 USA
- Vanderbilt Institute for Integrative Biosystems Research and Education; Vanderbilt University, Nashville, TN 37235 USA
- Department of Physics and Astronomy; Vanderbilt University, Nashville, TN 37235 USA
- Department of Molecular Physiology and Biophysics; Vanderbilt University, Nashville, TN 37235 USA
| | - William Hofmeister
- Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, TN 37388 USA
- Vanderbilt Institute for Integrative Biosystems Research and Education; Vanderbilt University, Nashville, TN 37235 USA
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Zhong W, Liu Q, Wu Y, Wang Y, Qing X, Li M, Liu K, Wang W, Wang D. A nanofiber based artificial electronic skin with high pressure sensitivity and 3D conformability. NANOSCALE 2016; 8:12105-12. [PMID: 27250529 DOI: 10.1039/c6nr02678h] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Pressure sensors with 3D conformability are highly desirable components for artificial electronic skin or e-textiles that can mimic natural skin, especially for application in real-time monitoring of human physiological signals. Here, a nanofiber based electronic skin with ultra-high pressure sensitivity and 3D conformability is designed and built by interlocking two elastic patterned nanofibrous membranes. The patterned membrane is facilely prepared by casting conductive nanofiber ink into a silicon mould to form an array of semi-spheroid-like protuberances. The protuberances composed of intertwined elastic POE nanofibers and PPy@PVA-co-PE nanofibers afford a tunable effective elastic modulus that is capable of capturing varied strains and stresses, thereby contributing to a high sensitivity for pressure sensing. This electronic skin-like sensor demonstrates an ultra-high sensitivity (1.24 kPa(-1)) below 150 Pa with a detection limit as low as about 1.3 Pa. The pixelated sensor array and a RGB-LED light are then assembled into a circuit and show a feasibility for visual detection of spatial pressure. Furthermore, a nanofiber based proof-of-concept wireless pressure sensor with a bluetooth module as a signal transmitter is proposed and has demonstrated great promise for wireless monitoring of human physiological signals, indicating a potential for large scale wearable electronic devices or e-skin.
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Affiliation(s)
- Weibin Zhong
- College of Materials Science and Engineering, Wuhan Textile University, Wuhan, 430200, China.
| | - Qiongzhen Liu
- College of Materials Science and Engineering, Wuhan Textile University, Wuhan, 430200, China.
| | - Yongzhi Wu
- College of Materials Science and Engineering, Wuhan Textile University, Wuhan, 430200, China.
| | - Yuedan Wang
- College of Materials Science and Engineering, Wuhan Textile University, Wuhan, 430200, China.
| | - Xing Qing
- College of Materials Science and Engineering, Wuhan Textile University, Wuhan, 430200, China.
| | - Mufang Li
- College of Materials Science and Engineering, Wuhan Textile University, Wuhan, 430200, China.
| | - Ke Liu
- College of Materials Science and Engineering, Wuhan Textile University, Wuhan, 430200, China.
| | - Wenwen Wang
- College of Materials Science and Engineering, Wuhan Textile University, Wuhan, 430200, China.
| | - Dong Wang
- College of Materials Science and Engineering, Wuhan Textile University, Wuhan, 430200, China.
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Hofmeister LH, Costa L, Balikov DA, Crowder SW, Terekhov A, Sung HJ, Hofmeister WH. Patterned polymer matrix promotes stemness and cell-cell interaction of adult stem cells. J Biol Eng 2015; 9:18. [PMID: 26464581 PMCID: PMC4603908 DOI: 10.1186/s13036-015-0016-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 09/21/2015] [Indexed: 12/27/2022] Open
Abstract
Background The interaction of stem cells with their culture substrates is critical in controlling their fate and function. Declining stemness of adult-derived human mesenchymal stem cells (hMSCs) during in vitro expansion on tissue culture polystyrene (TCPS) severely limits their therapeutic efficacy prior to cell transplantation into damaged tissues. Thus, various formats of natural and synthetic materials have been manipulated in attempts to reproduce in vivo matrix environments in which hMSCs reside. Results We developed a series of patterned polymer matrices for cell culture by hot-pressing poly(ε-caprolactone) (PCL) films in femtosecond laser-ablated nanopore molds, forming nanofibers on flat PCL substrates. hMSCs cultured on these PCL fiber matrices significantly increased expression of critical self-renewal factors, Nanog and OCT4A, as well as markers of cell-cell interaction PECAM and ITGA2. The results suggest the patterned polymer fiber matrix is a promising model to maintain the stemness of adult hMSCs. Conclusion This approach meets the need for scalable, highly repeatable, and tuneable models that mimic extracellular matrix features that signal for maintenance of hMSC stemness.
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Affiliation(s)
- Lucas H Hofmeister
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN USA
| | - Lino Costa
- Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, TN USA
| | - Daniel A Balikov
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN USA
| | - Spencer W Crowder
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN USA
| | - Alexander Terekhov
- Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, TN USA
| | - Hak-Joon Sung
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN USA
| | - William H Hofmeister
- Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, TN USA
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Feldman D. Polyblend Nanocomposites. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 2015. [DOI: 10.1080/10601325.2015.1050638] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kolodziejczyk B, Winther-Jensen O, Pereira BA, Nair SS, Winther-Jensen B. Patterning of conducting layers on breathable substrates using laser engraving for gas sensors. J Appl Polym Sci 2015. [DOI: 10.1002/app.42359] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Orawan Winther-Jensen
- Department of Materials Engineering; Monash University; Clayton Victoria 3800 Australia
| | - Brooke A. Pereira
- Department of Materials Engineering; Monash University; Clayton Victoria 3800 Australia
| | - Santhosh S. Nair
- Department of Materials Engineering; Monash University; Clayton Victoria 3800 Australia
| | - Bjorn Winther-Jensen
- Department of Materials Engineering; Monash University; Clayton Victoria 3800 Australia
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12
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Fuse S, Takahashi R, Takahashi T. Facile, One-Step Synthesis of 5-Substituted Thieno[3,4-c]pyrrole-4,6-dione by Palladium-Catalyzed Carbonylative Amidation. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500273] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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13
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Hernandez-Rueda J, Götte N, Siegel J, Soccio M, Zielinski B, Sarpe C, Wollenhaupt M, Ezquerra TA, Baumert T, Solis J. Nanofabrication of tailored surface structures in dielectrics using temporally shaped femtosecond-laser pulses. ACS APPLIED MATERIALS & INTERFACES 2015; 7:6613-9. [PMID: 25762003 DOI: 10.1021/am508925m] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We have investigated the use of tightly focused, temporally shaped femtosecond (fs)-laser pulses for producing nanostructures in two dielectric materials (sapphire and phosphate glass) with different characteristics in their response to pulsed laser radiation. For this purpose, laser pulses shaped by third-order dispersion (TOD) were used to generate temporally asymmetric excitation pulses, leading to the single-step production of subwavelength ablative and subablative surface structures. When compared to previous works on the interaction of tightly focused TOD-shaped pulses with fused silica, we show here that this approach leads to very different nanostructure morphologies, namely, clean nanopits without debris surrounding the crater in sapphire and well-outlined nanobumps and nanovolcanoes in phosphate glass. Although in sapphire the debris-free processing is associated with the much lower viscosity of the melt compared to fused silica, nanobump formation in phosphate glass is caused by material network expansion (swelling) upon resolidification below the ablation threshold. The formation of nanovolcanoes is a consequence of the combined effect of material network expansion and ablation occurring in the periphery and central part of the irradiated region, respectively. It is shown that the induced morphologies can be efficiently controlled by modulating the TOD coefficient of the temporally shaped pulses.
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Affiliation(s)
| | - Nadine Götte
- §Institut für Physik, Universität Kassel, Heinrich-Plett-Strasse 40, 34132 Kassel, Germany
| | | | | | - Bastian Zielinski
- §Institut für Physik, Universität Kassel, Heinrich-Plett-Strasse 40, 34132 Kassel, Germany
| | - Cristian Sarpe
- §Institut für Physik, Universität Kassel, Heinrich-Plett-Strasse 40, 34132 Kassel, Germany
| | - Matthias Wollenhaupt
- §Institut für Physik, Universität Kassel, Heinrich-Plett-Strasse 40, 34132 Kassel, Germany
- ∥Carl von Ossietzky Universität Oldenburg, Institut für Physik, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | | | - Thomas Baumert
- §Institut für Physik, Universität Kassel, Heinrich-Plett-Strasse 40, 34132 Kassel, Germany
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Tian H, Wang C, Shao J, Ding Y, Li X. Electrohydrodynamic pressure enhanced by free space charge for electrically induced structure formation with high aspect ratio. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:12654-12663. [PMID: 25268463 DOI: 10.1021/la5027043] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Electrically induced structure formation (EISF) is an interesting and unique approach for generating a microstructured duplicate from a rheological polymer by a spatially modulated electric field induced by a patterned template. Most of the research on EISF have so far used various dielectric polymers (with an electrical conductivity smaller than 10(-10) S/m that can be considered a perfect dielectric), on which the electric field induces a Maxwell stress only due to the dipoles (or bounded charges) in the polymer molecules, leading to a structure with a small aspect ratio. This paper presents a different approach for improving the aspect ratio allowed in EISF by doping organic salt into the perfect dielectric polymer, i.e., turning the perfect dielectric into a leaky dielectric, considering the fact that the free space charges enriched in the leaky dielectric polymer can make an additional contribution to the Maxwell stress, i.e., electrohydrodynamic pressure, which is desirable for high aspect ratio structuring. Our numerical simulations and experimental tests have shown that a leaky dielectric polymer, with a small conductivity comparable to that of deionized water, can be much more effective at being electrohydrodynamically deformed into a high aspect ratio in comparison with a perfect dielectric polymer when both of them have roughly the same dielectric constant.
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Affiliation(s)
- Hongmiao Tian
- Micro- and Nano-technology Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an, Shaanxi 710049, China
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15
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Paraecattil AA, Banerji N. Charge Separation Pathways in a Highly Efficient Polymer: Fullerene Solar Cell Material. J Am Chem Soc 2014; 136:1472-82. [DOI: 10.1021/ja410340g] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Arun Aby Paraecattil
- Institute
of Chemical Sciences
and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), SB
ISIC GR-MO, Station 6, CH-1015 Lausanne, Switzerland
| | - Natalie Banerji
- Institute
of Chemical Sciences
and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), SB
ISIC GR-MO, Station 6, CH-1015 Lausanne, Switzerland
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16
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Hu J, Luo Q, Zhang Z, Huang Y, Yang D, Pu X, Lu Z. Self-assembled nanopillar arrays by simple spin coating from blending systems comprising PC61BM and conjugated polymers with special structure. RSC Adv 2014. [DOI: 10.1039/c4ra03145h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Three conjugated D–A copolymers were found to form well-defined nanopillar arrays through a facile spin-casting process when blended with fullerene derivatives.
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Affiliation(s)
- Jian Hu
- Key Laboratory of Green Chemistry and Technology (Ministry of Education)
- College of Chemistry
- Sichuan University
- Chengdu 610064, PR China
| | - Qian Luo
- Key Laboratory of Green Chemistry and Technology (Ministry of Education)
- College of Chemistry
- Sichuan University
- Chengdu 610064, PR China
| | - Zhanyuan Zhang
- Key Laboratory of Green Chemistry and Technology (Ministry of Education)
- College of Chemistry
- Sichuan University
- Chengdu 610064, PR China
| | - Yan Huang
- Key Laboratory of Green Chemistry and Technology (Ministry of Education)
- College of Chemistry
- Sichuan University
- Chengdu 610064, PR China
| | - Daobin Yang
- Key Laboratory of Green Chemistry and Technology (Ministry of Education)
- College of Chemistry
- Sichuan University
- Chengdu 610064, PR China
| | - Xuemei Pu
- Key Laboratory of Green Chemistry and Technology (Ministry of Education)
- College of Chemistry
- Sichuan University
- Chengdu 610064, PR China
| | - Zhiyun Lu
- Key Laboratory of Green Chemistry and Technology (Ministry of Education)
- College of Chemistry
- Sichuan University
- Chengdu 610064, PR China
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17
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High-aspect-ratio conducting polymer microtube synthesis by light-activated electropolymerization on microstructured silicon. Electrochem commun 2013. [DOI: 10.1016/j.elecom.2013.07.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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