1
|
Synthesis of poly(silyl ether)s via copper-catalyzed dehydrocoupling polymerization. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2021.09.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
2
|
Rosen ME, Dallon JC. A mathematical analysis of focal adhesion lifetimes and their effect on cell motility. Biophys J 2022; 121:1070-1080. [PMID: 35143774 PMCID: PMC8943753 DOI: 10.1016/j.bpj.2022.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 12/07/2021] [Accepted: 02/03/2022] [Indexed: 11/02/2022] Open
Abstract
By analyzing the distributions of focal adhesion (FA) lifetimes from different cell types, we found that a gamma distribution best matched the experimental distributions. In all but one case, it was a unimodal, non-symmetric gamma distribution. We used a mathematical model of cell motion to help understand the mechanics and data behind the FA lifetime distributions. The model uses a detach-rate function to determine how long an FA will persist before it detaches. The detach-rate function that produced distributions with a best-fit gamma curve that closely matched that of the data was both force and time dependent. Using the data gathered from the matching simulations, we calculated both the cell speed and mean FA lifetime and compared them. Where available, we also compared this relationship to that of the experimental data and found that the simulation reasonably matches it in most cases. In both the simulations and experimental data, the cell speed and mean FA lifetime are related, with longer mean lifetimes being indicative of slower speeds. We suspect that one of the main predictors of cell speed for migrating cells is the distribution of the FA lifetimes.
Collapse
Affiliation(s)
- Mary Ellen Rosen
- Department of Mathematics, Brigham Young University, Provo, Utah
| | - J C Dallon
- Department of Mathematics, Brigham Young University, Provo, Utah.
| |
Collapse
|
3
|
Deriabin KV, Dobrynin MV, Islamova RM. A metal-free radical technique for cross-linking of polymethylhydrosiloxane or polymethylvinylsiloxane using AIBN. Dalton Trans 2020; 49:8855-8858. [PMID: 32589173 DOI: 10.1039/d0dt01061h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new method was developed for the metal-free cross-linking of silicone rubbers. This process uses azobisisobutyronitrile (AIBN) to selectively react with Si-H and vinyl groups as a free-radical initiator for the thermal curing of polymethylhydrosiloxane (PMHS) and polymethylvinylsiloxane (PMVS). The AIBN-initiated curing reaction between the Si-H groups of PMHS generated Si-O-Si and Si-Si cross-links. In contrast, PMVS was cured via the formation of C-C bonds through "methyl-vinyl" and "vinyl-vinyl" mechanisms. Curing reactions were performed at 80-120 °C in air and confirmed by 13C and 29Si solid state NMR analyses and swelling trials.
Collapse
Affiliation(s)
- Konstantin V Deriabin
- Saint Petersburg State University, 7/9, Universitetskaya nab., Saint Petersburg, 199034, Russia.
| | | | | |
Collapse
|
4
|
Lemonier S, Marty J, Fitremann J. Polysiloxanes Modified by Thiol‐Ene Reaction and Their Interaction with Gold Nanoparticles. Helv Chim Acta 2019. [DOI: 10.1002/hlca.201900180] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Stéphane Lemonier
- IMRCPUniversité de ToulouseCNRSBat 2R1 118 Route de Narbonne FR-31062 Toulouse Cedex 9 France
| | - Jean‐Daniel Marty
- IMRCPUniversité de ToulouseCNRSBat 2R1 118 Route de Narbonne FR-31062 Toulouse Cedex 9 France
| | - Juliette Fitremann
- IMRCPUniversité de ToulouseCNRSBat 2R1 118 Route de Narbonne FR-31062 Toulouse Cedex 9 France
| |
Collapse
|
5
|
Sample CS, Lee SH, Li S, Bates MW, Lensch V, Versaw BA, Bates CM, Hawker CJ. Metal-Free Room-Temperature Vulcanization of Silicones via Borane Hydrosilylation. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01585] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Caitlin S. Sample
- Department of Chemistry and Biochemistry, Materials Department, and Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Sang-Ho Lee
- Department of Chemistry and Biochemistry, Materials Department, and Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
- Research Center for Green Fine Chemicals, Korea Research Institute of Chemical Technology, Ulsan 44412, Republic of Korea
| | - Shaoguang Li
- Department of Chemistry and Biochemistry, Materials Department, and Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Morgan W. Bates
- Department of Chemistry and Biochemistry, Materials Department, and Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Valerie Lensch
- Department of Chemistry and Biochemistry, Materials Department, and Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Brooke A. Versaw
- Department of Chemistry and Biochemistry, Materials Department, and Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Christopher M. Bates
- Department of Chemistry and Biochemistry, Materials Department, and Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Craig J. Hawker
- Department of Chemistry and Biochemistry, Materials Department, and Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| |
Collapse
|
6
|
Shivapooja P, Yu Q, Orihuela B, Mays R, Rittschof D, Genzer J, López GP. Modification of Silicone Elastomer Surfaces with Zwitterionic Polymers: Short-Term Fouling Resistance and Triggered Biofouling Release. ACS APPLIED MATERIALS & INTERFACES 2015; 7:25586-25591. [PMID: 26554418 DOI: 10.1021/acsami.5b09199] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present a method for dual-mode-management of biofouling by modifying surface of silicone elastomers with zwitterionic polymeric grafts. Poly(sulfobetaine methacrylate) was grafted from poly(vinylmethylsiloxane) elastomer substrates using thiol-ene click chemistry and surface-initiated, controlled radical polymerization. These surfaces exhibited both fouling resistance and triggered fouling-release functionality. The zwitterionic polymers exhibited fouling resistance over short-term (∼hours) exposure to bacteria and barnacle cyprids. The biofilms that eventually accumulated over prolonged-exposure (∼days) were easily detached by applying mechanical strain to the elastomer substrate. Such dual-functional surfaces may be useful in developing environmentally and biologically friendly coatings for biofouling management on marine, industrial, and biomedical equipment because they can obviate the use of toxic compounds.
Collapse
Affiliation(s)
| | - Qian Yu
- College of Chemistry, Chemical Engineering and Material Science, Soochow University , Suzhou 215123, China
| | - Beatriz Orihuela
- Marine Science and Conservation, Duke University Marine Laboratory , Beaufort, North Carolina 28516, United States
| | - Robin Mays
- Department of Chemical and Biomolecular Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States
| | - Daniel Rittschof
- Marine Science and Conservation, Duke University Marine Laboratory , Beaufort, North Carolina 28516, United States
| | - Jan Genzer
- Department of Chemical and Biomolecular Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States
| | | |
Collapse
|
7
|
Özçam AE, Spontak RJ, Genzer J. Toward the development of a versatile functionalized silicone coating. ACS APPLIED MATERIALS & INTERFACES 2014; 6:22544-22552. [PMID: 25426681 DOI: 10.1021/am506661m] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The development of a versatile silicone copolymer coating prepared by the chemical coupling of trichlorosilane (TCS) to the vinyl groups of poly(vinylmethylsiloxane) (PVMS) is reported. The resultant PVMS-TCS copolymer can be deposited as a functional organic layer on a hydrophobic poly(dimethylsiloxane) substrate and its mechanical modulus can be regulated by varying the TCS coupling ratio. In this paper, several case studies demonstrating the versatile properties of these PVMS-TCS functional coatings on PDMS elastomer substrates are presented. Numerous experimental probes, including optical microscopy, Fourier-transform infrared spectroscopy, surface contact angle, ellipsometry, and nanoindentation, are utilized to interrogate the physical and chemical characteristics of these PVMS-TCS coatings.
Collapse
Affiliation(s)
- A Evren Özçam
- Department of Chemical & Biomolecular Engineering North Carolina State University Raleigh, North Carolina 27695-7905, United States
| | | | | |
Collapse
|
8
|
Effect of ultraviolet/ozone treatment on the surface and bulk properties of poly(dimethyl siloxane) and poly(vinylmethyl siloxane) networks. POLYMER 2014. [DOI: 10.1016/j.polymer.2014.05.027] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
9
|
Mas-Moruno C, Fraioli R, Albericio F, Manero JM, Gil FJ. Novel peptide-based platform for the dual presentation of biologically active peptide motifs on biomaterials. ACS APPLIED MATERIALS & INTERFACES 2014; 6:6525-6536. [PMID: 24673628 DOI: 10.1021/am5001213] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Biofunctionalization of metallic materials with cell adhesive molecules derived from the extracellular matrix is a feasible approach to improve cell-material interactions and enhance the biointegration of implant materials (e.g., osseointegration of bone implants). However, classical biomimetic strategies may prove insufficient to elicit complex and multiple biological signals required in the processes of tissue regeneration. Thus, newer strategies are focusing on installing multifunctionality on biomaterials. In this work, we introduce a novel peptide-based divalent platform with the capacity to simultaneously present distinct bioactive peptide motifs in a chemically controlled fashion. As a proof of concept, the integrin-binding sequences RGD and PHSRN were selected and introduced in the platform. The biofunctionalization of titanium with this platform showed a positive trend towards increased numbers of cell attachment, and statistically higher values of spreading and proliferation of osteoblast-like cells compared to control noncoated samples. Moreover, it displayed statistically comparable or improved cell responses compared to samples coated with the single peptides or with an equimolar mixture of the two motifs. Osteoblast-like cells produced higher levels of alkaline phosphatase on surfaces functionalized with the platform than on control titanium; however, these values were not statistically significant. This study demonstrates that these peptidic structures are versatile tools to convey multiple biofunctionality to biomaterials in a chemically defined manner.
Collapse
Affiliation(s)
- Carlos Mas-Moruno
- Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC) , ETSEIB, Avenida Diagonal 647, 08028 Barcelona, Spain
| | | | | | | | | |
Collapse
|
10
|
Mays RL, Dickey MD, Genzer J. Microfluidic channels fabricated from poly(vinylmethylsiloxane) networks that resist swelling by organic solvents. LAB ON A CHIP 2013; 13:4317-4320. [PMID: 24089248 DOI: 10.1039/c3lc50848j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This paper describes the use of poly(vinylmethylsiloxane) (PVMS) networks for fabricating microfluidic channels that resist swelling in the presence of organic solvents, thus providing a versatile alternative to poly(dimethylsiloxane) (PDMS). In particular, we demonstrate that in contrast to PDMS microchannels, the UV-treated PVMS structures exhibit high resistance to swelling by toluene.
Collapse
Affiliation(s)
- Robin L Mays
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA.
| | | | | |
Collapse
|
11
|
Shevchenko EK, Makarevich PI, Tsokolaeva ZI, Boldyreva MA, Sysoeva VY, Tkachuk VA, Parfyonova YV. Transplantation of modified human adipose derived stromal cells expressing VEGF165 results in more efficient angiogenic response in ischemic skeletal muscle. J Transl Med 2013; 11:138. [PMID: 23742074 PMCID: PMC3680170 DOI: 10.1186/1479-5876-11-138] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 05/29/2013] [Indexed: 01/21/2023] Open
Abstract
Background Modified cell-based angiogenic therapy has become a promising novel strategy for ischemic heart and limb diseases. Most studies focused on myoblast, endothelial cell progenitors or bone marrow mesenchymal stromal cells transplantation. Yet adipose-derived stromal cells (in contrast to bone marrow) are abundantly available and can be easily harvested during surgery or liposuction. Due to high paracrine activity and availability ADSCs appear to be a preferable cell type for cardiovascular therapy. Still neither genetic modification of human ADSC nor in vivo therapeutic potential of modified ADSC have been thoroughly studied. Presented work is sought to evaluate angiogenic efficacy of modified ADSCs transplantation to ischemic tissue. Materials and methods Human ADSCs were transduced using recombinant adeno-associated virus (rAAV) serotype 2 encoding human VEGF165. The influence of genetic modification on functional properties of ADSCs and their angiogenic potential in animal models were studied. Results We obtained AAV-modified ADSC with substantially increased secretion of VEGF (VEGF-ADSCs). Transduced ADSCs retained their adipogenic and osteogenic differentiation capacities and adhesion properties. The level of angiopoetin-1 mRNA was significantly increased in VEGF-ADSC compared to unmodified cells yet expression of FGF-2, HGF and urokinase did not change. Using matrigel implant model in mice it was shown that VEGF-ADSC substantially stimulated implant vascularization with paralleling increase of capillaries and arterioles. In murine hind limb ischemia test we found significant reperfusion and revascularization after intramuscular transplantation of VEGF-ADSC compared to controls with no evidence of angioma formation. Conclusions Transplantation of AAV-VEGF- gene modified hADSC resulted in stronger therapeutic effects in the ischemic skeletal muscle and may be a promising clinical treatment for therapeutic angiogenesis.
Collapse
Affiliation(s)
- Evgeny K Shevchenko
- Laboratory of angiogenesis, Russian Cardiology Research and Production Complex, 3rd Cherepkovskaya 15A, Moscow, 121552, Russia.
| | | | | | | | | | | | | |
Collapse
|
12
|
Cho H, Balaji S, Sheikh AQ, Hurley JR, Tian YF, Collier JH, Crombleholme TM, Narmoneva DA. Regulation of endothelial cell activation and angiogenesis by injectable peptide nanofibers. Acta Biomater 2012; 8:154-64. [PMID: 21925628 DOI: 10.1016/j.actbio.2011.08.029] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 08/12/2011] [Accepted: 08/31/2011] [Indexed: 11/17/2022]
Abstract
RAD16-II peptide nanofibers are promising for vascular tissue engineering and were shown to enhance angiogenesis in vitro and in vivo, although the mechanism remains unknown. We hypothesized that the pro-angiogenic effect of RAD16-II results from low-affinity integrin-dependent interactions of microvascular endothelial cells (MVECs) with RAD motifs. Mouse MVECs were cultured on RAD16-II with or without integrin and MAPK/ERK pathway inhibitors, and angiogenic responses were quantified. The results were validated in vivo using a mouse diabetic wound healing model with impaired neovascularization. RAD16-II stimulated spontaneous capillary morphogenesis, and increased β(3) integrin phosphorylation and VEGF expression in MVECs. These responses were abrogated in the presence of β(3) and MAPK/ERK pathway inhibitors or on the control peptide without RAD motifs. Wide-spectrum integrin inhibitor echistatin completely abolished RAD16-II-mediated capillary morphogenesis in vitro and neovascularization and VEGF expression in the wound in vivo. The addition of the RGD motif to RAD16-II did not change nanofiber architecture or mechanical properties, but resulted in significant decrease in capillary morphogenesis. Overall, these results suggest that low-affinity non-specific interactions between cells and RAD motifs can trigger angiogenic responses via phosphorylation of β(3) integrin and MAPK/ERK pathway, indicating that low-affinity sequences can be used to functionalize biocompatible materials for the regulation of cell migration and angiogenesis, thus expanding the current pool of available motifs that can be used for such functionalization. Incorporation of RAD or similar motifs into protein engineered or hybrid peptide scaffolds may represent a novel strategy for vascular tissue engineering and will further enhance design opportunities for new scaffold materials.
Collapse
Affiliation(s)
- Hongkwan Cho
- School of Energy, Environmental, Biological, and Medical Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | | | | | | | | | | | | | | |
Collapse
|