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Cheung BCH, Hodgson L, Segall JE, Wu M. Spatial and temporal dynamics of RhoA activities of single breast tumor cells in a 3D environment revealed by a machine learning-assisted FRET technique. Exp Cell Res 2022; 410:112939. [PMID: 34813733 PMCID: PMC8714707 DOI: 10.1016/j.yexcr.2021.112939] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 01/17/2023]
Abstract
One of the hallmarks of cancer cells is their exceptional ability to migrate within the extracellular matrix (ECM) for gaining access to the circulatory system, a critical step of cancer metastasis. RhoA, a small GTPase, is known to be a key molecular switch that toggles between actomyosin contractility and lamellipodial protrusion during cell migration. Current understanding of RhoA activity in cell migration has been largely derived from studies of cells plated on a two-dimensional (2D) substrate using a FRET biosensor. There has been increasing evidence that cells behave differently in a more physiologically relevant three-dimensional (3D) environment. However, studies of RhoA activities in 3D have been hindered by low signal-to-noise ratio in fluorescence imaging. In this paper, we present a a machine learning-assisted FRET technique to follow the spatiotemporal dynamics of RhoA activities of single breast tumor cells (MDA-MB-231) migrating in a 3D as well as a 2D environment. We found that RhoA activity is more polarized along the long axis of the cell for single cells migrating on 2D fibronectin-coated glass versus those embedded in 3D collagen matrices. In particular, RhoA activities of cells in 2D exhibit a distinct front-to-back and back-to-front movement during migration in contrast to those in 3D. Finally, regardless of dimensionality, RhoA polarization is found to be moderately correlated with cell shape.
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Affiliation(s)
- Brian CH Cheung
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Louis Hodgson
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA,Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Jeffrey E Segall
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Mingming Wu
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA,Corresponding author:
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2
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Kikuchi T, Matsuura K, Shimizu T. Non-coating method for non-adherent cell culture using high molecular weight dextran sulfate and bovine serum albumin. J Biosci Bioeng 2021; 132:537-542. [PMID: 34518107 DOI: 10.1016/j.jbiosc.2021.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/12/2021] [Accepted: 08/18/2021] [Indexed: 11/19/2022]
Abstract
Non-adherent cell culture surface has been widely used for producing cell spheroids and cell aggregates. The purpose of this study was to formulate a new method for non-adherent cell culture without coating or surface-modification that has been needed. We found that high-molecular-weight dextran sulfate (DS) and bovine serum albumin (BSA) synergistically prevented cell adhesion in media supplemented with no or low serum. This method worked on tissue culture-treated polystyrene surfaces as well as on commercially available low-attachment- and untreated polystyrene surfaces. Further investigation revealed that BSA may mediate the adsorption of DS to the surface. In addition, as the adsorption of fluorescently labeled fibronectin was inhibited by BSA alone, it appears that protein adsorption and cell adhesion do not always correlate. Finally, we demonstrated the successful formation of HepG2 spheroids and cardiomyocyte aggregates using this method. In conclusion, cell adhesion can be effectively suppressed by simply adding DS and BSA to the culture medium without coating or surface modification, and it may be useful for generating cell spheroids and aggregates.
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Affiliation(s)
- Tetsutaro Kikuchi
- Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University (TWIns), 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
| | - Katsuhisa Matsuura
- Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University (TWIns), 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Tatsuya Shimizu
- Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University (TWIns), 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
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3
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Protein Interactions at Material Surfaces. Biomed Mater 2021. [DOI: 10.1007/978-3-030-49206-9_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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4
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Ishihara K, Mitera K, Inoue Y, Fukazawa K. Effects of molecular interactions at various polymer brush surfaces on fibronectin adsorption induced cell adhesion. Colloids Surf B Biointerfaces 2020; 194:111205. [DOI: 10.1016/j.colsurfb.2020.111205] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/06/2020] [Accepted: 06/16/2020] [Indexed: 02/06/2023]
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5
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Begum R, Perriman AW, Su B, Scarpa F, Kafienah W. Chondroinduction of Mesenchymal Stem Cells on Cellulose-Silk Composite Nanofibrous Substrates: The Role of Substrate Elasticity. Front Bioeng Biotechnol 2020; 8:197. [PMID: 32266231 PMCID: PMC7096586 DOI: 10.3389/fbioe.2020.00197] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 02/28/2020] [Indexed: 01/09/2023] Open
Abstract
Smart biomaterials with an inherent capacity to elicit specific behaviors in lieu of biological prompts would be advantageous for regenerative medicine applications. In this work, we employ an electrospinning technique to model the in vivo nanofibrous extracellular matrix (ECM) of cartilage using a chondroinductive cellulose and silk polymer blend (75:25 ratio). This natural polymer composite is directly electrospun for the first time, into nanofibers without post-spun treatment, using a trifluoroacetic acid and acetic acid cosolvent system. Biocompatibility of the composite nanofibres with human mesenchymal stem cells (hMSCs) is demonstrated and its inherent capacity to direct chondrogenic stem cell differentiation, in the absence of stimulating growth factors, is confirmed. This chondrogenic stimulation could be countered biochemically using fibroblast growth factor-2, a growth factor used to enhance the proliferation of hMSCs. Furthermore, the potential mechanisms driving this chondroinduction at the cell-biomaterial interface is investigated. Composite substrates are fabricated as two-dimensional film surfaces and cultured with hMSCs in the presence of chemicals that interfere with their biochemical and mechanical signaling pathways. Preventing substrate surface elasticity transmission resulted in a significant downregulation of chondrogenic gene expression. Interference with the classical chondrogenic Smad2/3 phosphorylation pathway did not impact chondrogenesis. The results highlight the importance of substrate mechanical elasticity on hMSCs chondroinduction and its independence to known chondrogenic biochemical pathways. The newly fabricated scaffolds provide the foundation for designing a robust, self-inductive, and cost-effective biomimetic biomaterial for cartilage tissue engineering.
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Affiliation(s)
- Runa Begum
- Faculty of Biomedical Sciences, School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - Adam W Perriman
- Faculty of Biomedical Sciences, School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - Bo Su
- Bristol Dental School, University of Bristol, Bristol, United Kingdom
| | - Fabrizio Scarpa
- Bristol Composites Institute (ACCIS), University of Bristol, Bristol, United Kingdom
| | - Wael Kafienah
- Faculty of Biomedical Sciences, School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
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6
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Rohman G, Huot S, Vilas-Boas M, Radu-Bostan G, Castner DG, Migonney V. The grafting of a thin layer of poly(sodium styrene sulfonate) onto poly(ε-caprolactone) surface can enhance fibroblast behavior. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2015; 26:206. [PMID: 26155977 PMCID: PMC4554533 DOI: 10.1007/s10856-015-5539-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 07/03/2015] [Indexed: 05/25/2023]
Abstract
Poly(sodium styrene sulfonate) (pNaSS) was grafted onto poly(ε-caprolatone) (PCL) surfaces via ozonation and graft polymerization. The effect of ozonation and polymerization time, as well as the Mohr's salt concentration in the grafting solution, on the degree of grafting was investigated. The degree of grafting was determined through toluidine blue staining. The surface chemical change was characterized by attenuated total reflection Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The result demonstrated that the grafting did not induce any degradation of PCL, and that pNaSS was grafted onto PCL as a thin and covalently stable layer. Furthermore, the modified PCL surface reveals a significant increase in the metabolic activity of fibroblastic cells, as well as a better cell spreading with higher adhesion strength. Consequently, bioactivity of PCL is greatly enhanced by immobilizing a thin layer of pNaSS onto its surface. The grafting of pNaSS is a promising approach to increase the bioactivity of PCL-based materials used in tissue engineering applications, such as ligament reconstruction.
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Affiliation(s)
- Géraldine Rohman
- Université Paris 13, Sorbonne Paris Cité, Laboratoire de Chimie, Structures, Propriétés de Biomatériaux et d'Agents Thérapeutiques (CSPBAT), CNRS UMR 7244, 93430, Villetaneuse, France,
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7
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Gengec NA, Gulsuner HU, Erbil HY, Tekinay AB. Selective adsorption of L1210 leukemia cells/human leukocytes on micropatterned surfaces prepared from polystyrene/polypropylene-polyethylene blends. Colloids Surf B Biointerfaces 2014; 113:403-11. [PMID: 24135453 DOI: 10.1016/j.colsurfb.2013.09.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 08/21/2013] [Accepted: 09/18/2013] [Indexed: 01/23/2023]
Abstract
The objective of this study is to prepare polymeric surfaces which will adsorb L1210 leukemia cells selectively more than that of healthy human leukocytes in order to develop new treatment options for people with leukemia. Chemically heterogeneous and micropatterned surfaces were formed on round glass slides by dip coating with accompanying phase-separation process where only commercial polymers were used. Surface properties were determined by using optical microscopy, 3D profilometry, SEM and measuring contact angles. Polymer, solvent/nonsolvent types, blend composition and temperature were found to be effective in controlling the dimensions of surface microislands. MTT tests were applied for cell viability performance of these surfaces. Polystyrene/polyethylene-polypropylene blend surfaces were found to show considerable positive selectivity to L1210 leukemia cells where L1210/healthy leukocytes adsorption ratio approached to 9-fold in vitro. Effects of wettability, surface free energy, microisland size geometry on the adsorption performances of L1210/leukocytes pairs are discussed.
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Affiliation(s)
- Nevin Atalay Gengec
- Gebze Institute of Technology, Department of Chemical Engineering, 41400 Gebze, Kocaeli, Turkey
| | - Hilal Unal Gulsuner
- Institute of Materials Science and Nanotechnology, National Nanotechnology Research Center (UNAM), Bilkent University, 06800 Ankara, Turkey
| | - H Yildirim Erbil
- Gebze Institute of Technology, Department of Chemical Engineering, 41400 Gebze, Kocaeli, Turkey.
| | - Ayse Begum Tekinay
- Institute of Materials Science and Nanotechnology, National Nanotechnology Research Center (UNAM), Bilkent University, 06800 Ankara, Turkey
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An improved freeze-dried PRP-coated biodegradable material suitable for connective tissue regenerative therapy. Cryobiology 2013; 66:223-32. [PMID: 23422785 DOI: 10.1016/j.cryobiol.2013.01.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 01/30/2013] [Accepted: 01/31/2013] [Indexed: 02/05/2023]
Abstract
We previously published an investigation indicating freeze-dried platelet-rich plasma (PRP)-coated polyglactin mesh was a promising wound-dressing material. However, one of its disadvantages was the inflammatory nature due to degradation of the polyglactin. Therefore, in this study, we investigated the use of a collagen sponge as the carrier for PRP. When implanted subcutaneously in nude mice, the PRP-coated sponge alone rapidly induced angiogenesis and infiltration of surrounding connective tissue without inducing appreciable inflammation. Moreover, addition of periosteal fibroblastic cells substantially augmented the angiogenic response. With in vitro studies, the PRP-coated sponge provided various major growth factors at high levels to stimulate the proliferation of cells cultured on plastic dishes, but did not stimulate the proliferation of cells inoculated into the PRP-coated sponge. Cells were embedded in the fibrin mesh and maintained their spherical shape without stretching. The atomic force microscopic analysis demonstrated that the fibrin gel formed on the PRP-coated sponge was much softer (approx. 22 kPa) than the cross-linked collagen that formed the sponge base (appox. 1.9 MPa). Because insoluble matrices have recently and increasingly been considered important regulatory factors of cellular behavior, as are soluble growth factors, it is suggested that this soft fibrin mesh possibly suppresses cell survival. Overall, our investigation has successfully demonstrated improved wound-healing and regenerative potential of the PRP-coated mesh by combining it with the collagen sponge. In the clinical setting, this PRP-coated collagen sponge is a promising material for connective tissue regenerative therapy, such as periodontal therapy, burn victim treatment and in cosmetic or plastic surgery.
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9
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Kisiel M, Martino MM, Ventura M, Hubbell JA, Hilborn J, Ossipov DA. Improving the osteogenic potential of BMP-2 with hyaluronic acid hydrogel modified with integrin-specific fibronectin fragment. Biomaterials 2012; 34:704-12. [PMID: 23103154 DOI: 10.1016/j.biomaterials.2012.10.015] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Accepted: 10/05/2012] [Indexed: 01/08/2023]
Abstract
While human bone morphogenetic protein-2 (rhBMP-2) is a promising growth factor for bone regeneration, its clinical efficacy has recently shown to be below expectation. In order to improve the clinical translation of rhBMP-2, there exists strong motivation to engineer better delivery systems. Hyaluronic acid (HA) hydrogel is a suitable carrier for the delivery of rhBMP-2, but a major limitation of this scaffold is its low cell adhesive properties. In this study, we have determined whether covalent grafting of an integrin-specific ligands into HA hydrogel could improve cell attachment and further enhance the osteogenic potential of rhBMP-2. A structurally stabilized fibronectin (FN) fragment containing the major integrin-binding domain of full-length FN (FN III9*-10) was engineered, in order to be incorporated into HA hydrogel. Compared to non-functionalized HA hydrogel, HA-FN hydrogel remarkably improved the capacity of the material to support mesenchymal stem cell attachment and spreading. In an ectopic bone formation model in the rat, delivery of rhBMP-2 with HA-FN hydrogel resulted in the formation of twice as much bone with better organization of collagen fibers compared to delivering the growth factor in non-functionalized HA hydrogel. This engineered hydrogel carrier for rhBMP-2 can be relevant in clinical bone repair.
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Affiliation(s)
- Marta Kisiel
- Division of Polymer Chemistry, Department of Chemistry-Ångström Laboratory, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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10
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Molino PJ, Higgins MJ, Innis PC, Kapsa RMI, Wallace GG. Fibronectin and bovine serum albumin adsorption and conformational dynamics on inherently conducting polymers: a QCM-D study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:8433-8445. [PMID: 22551342 DOI: 10.1021/la300692y] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Quartz crystal microbalance with dissipation monitoring (QCM-D) was employed to characterize the adsorption of the model proteins, bovine serum albumin (BSA) and fibronectin (FN), to polypyrrole doped with dextran sulfate (PPy-DS) as a function of DS loading and surface roughness. BSA adsorption was greater on surfaces of increased roughness and was above what could be explained by the increase in surface area alone. Furthermore, the additional mass adsorbed on the rough films was concomitant with an increase in the rigidity of the protein layer. Analysis of the dynamic viscoelastic properties of the protein adlayer reveal BSA adsorption on the rough films occurs in two phases: (1) arrival and initial adsorption of protein to the polymer surface and (2) postadsorption molecular rearrangement to a more dehydrated and compact conformation that facilitates further recruitment of protein to the polymer interface, likely forming a multilayer. In contrast, FN adsorption was independent of surface roughness. However, films prepared from solutions containing the highest concentration of DS (20 mg/mL) demonstrated both an increase in adsorbed mass and adlayer viscoelasticity. This is attributed to the higher DS loading in the conducting polymer film resulting in presentation of a more hydrated molecular structure indicative of a more unfolded and bioactive conformation. Modulating the redox state of the PPy-DS polymers was shown to modify both the adsorbed mass and viscoelastic nature of FN adlayers. An oxidizing potential increased both the total adsorbed mass and the adlayer viscoelasticity. Our findings demonstrate that modification of polymer physicochemical and redox condition alters the nature of protein-polymer interaction, a process that may be exploited to tailor the bioactivity of protein through which interactions with cells and tissues may be controlled.
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Affiliation(s)
- Paul J Molino
- ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, Wollongong, New South Wales 2522, Australia
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11
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Elter P, Weihe T, Bühler S, Gimsa J, Beck U. Low fibronectin concentration overcompensates for reduced initial fibroblasts adhesion to a nanoscale topography: Single-cell force spectroscopy. Colloids Surf B Biointerfaces 2012; 95:82-9. [DOI: 10.1016/j.colsurfb.2012.02.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Revised: 01/18/2012] [Accepted: 02/14/2012] [Indexed: 11/29/2022]
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12
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Hang R, Zhang M, Ma S, Chu PK. Biological response of endothelial cells to diamond-like carbon-coated NiTi alloy. J Biomed Mater Res A 2011; 100:496-506. [PMID: 22125203 DOI: 10.1002/jbm.a.33295] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Revised: 07/11/2011] [Accepted: 09/26/2011] [Indexed: 11/08/2022]
Abstract
Diamond-like carbon (DLC) coatings were deposited on nearly equiatomic nickel-titanium (NiTi) alloy by arc-enhanced magnetron sputtering. The microstructure, surface morphology, chemical composition, surface free energy, protein adsorbance, and leach amount of Ni ions were assessed by Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), contact angle measurements, micro BCA™ protein assay kit, and inductively coupled plasma mass spectrometry (ICP-MS). The biological response of the endothelial cells (ECs) was evaluated by cell adhesion, morphology, viability, and expression levels of thrombogenicity-related genes. Our results show that the DLC coatings inhibit the release of Ni ions from the NiTi substrate effectively thus enhancing its biosafety. The easy adhesion, elongated morphology, and high viability of ECs on the DLC coatings suggest fast endothelialization after implantation and so application of DLC coatings improves the surface properties of NiTi in cardiovascular applications. The relationship between the surface characteristics, Ni leaching, and concomitant biological response are discussed in details.
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Affiliation(s)
- Ruiqiang Hang
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
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Moby V, Labrude P, Kadi A, Bordenave L, Stoltz JF, Menu P. Polyelectrolyte multilayer film and human mesenchymal stem cells: An attractive alternative in vascular engineering applications. J Biomed Mater Res A 2010; 96:313-9. [DOI: 10.1002/jbm.a.32981] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 09/01/2010] [Accepted: 09/02/2010] [Indexed: 01/16/2023]
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Bush KA, Pins GD. Carbodiimide conjugation of fibronectin on collagen basal lamina analogs enhances cellular binding domains and epithelialization. Tissue Eng Part A 2010; 16:829-38. [PMID: 19778179 DOI: 10.1089/ten.tea.2009.0514] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
To improve the regenerative potential of biomaterials used as bioengineered scaffolds, it is necessary to strategically incorporate biologically active molecules that promote in vivo cellular processes that lead to a fully functional tissue. This work evaluates the effects of strategically binding fibronectin (FN) to collagen basal lamina analogs to enhance keratinocyte functions necessary for complete skin regeneration. We found that FN that was passively adsorbed to collagen-glycosaminoglycan basal lamina analogs enhanced epithelial thickness and keratinocyte proliferation compared with nontreated basal lamina analogs at 3 days of air/liquid (A/L) interface culture. Additionally, we evaluated the availability of FN cellular binding site domains when FN was either passively adsorbed or [1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride] conjugated to basal lamina analogs fabricated from collagen-glycosaminoglycan coprecipitate or self-assembled type I collagen. It was found that 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride conjugation of FN significantly enhanced FN binding site presentation as well as epithelial thickness. Overall, the results gained from this study will be used to improve the regenerative capacity of basal lamina analogs for bioengineered skin substitutes as well as the development of bioengineered scaffolds for other tissue engineering applications.
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Affiliation(s)
- Katie A Bush
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA 01606, USA
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15
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Kowalczyńska HM, Kołos R, Nowak-Wyrzykowska M, Dobkowski J, Elbaum D, Szczepankiewicz A, Kamiński J. Atomic force microscopy evidence for conformational changes of fibronectin adsorbed on unmodified and sulfonated polystyrene surfaces. J Biomed Mater Res A 2010; 91:1239-51. [PMID: 19358257 DOI: 10.1002/jbm.a.32473] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effect of polystyrene surface polarity on the conformation of adsorbed fibronectin (FN) has been studied with atomic force microscopy. We demonstrated that bare sulfonated and nonsulfonated polystyrene surfaces featured similar topographies. After the FN adsorption, direct comparison of both types of substrata revealed drastically different topographies, roughness values, and also cell-adhesive properties. This was interpreted in terms of FN conformational changes induced by the surface polarity. At high-solute FN concentrations the multilayer FN adsorption took place resulting, for the sulfonated substratum, in an increase of surface roughness, whereas for the nonsulfonated one the roughness was approximately stable. Conversely, the FN conformation characteristic for the first saturative layer tended to be conserved in the consecutive layers, as evidenced by height histograms. The height of individual FN molecules indicated, consonantly with the derived thickness of the adsorbed protein layer (the latter value being 1.4 nm and 0.6 nm, respectively, for an unmodified and sulfonated polystyrene surface), that molecules are flattened on polar surfaces and more compact on nonsulfonated ones. It was also demonstrated that the FN adsorption and conformation on polymeric substrata, and hence the resultant cell-adhesive properties, depended on the chemistry of the original surface rather than on its topography. Our results also demonstrated the ability of surface polarity to influence the protein conformation and its associated biological activity.
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Affiliation(s)
- Hanna M Kowalczyńska
- Department of Biophysics, Medical Centre for Postgraduate Education, ul Marymoncka 99, 01-813 Warszawa, Poland
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16
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Liu ZM, Lee SY, Sarun S, Peschel D, Groth T. Immobilization of poly (ethylene imine) on poly (L-lactide) promotes MG63 cell proliferation and function. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2009; 20:2317-2326. [PMID: 19565188 DOI: 10.1007/s10856-009-3806-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Accepted: 06/16/2009] [Indexed: 05/28/2023]
Abstract
Poly (ethylene imine) (PEI) is a polycation widely used for DNA transfection to cells but also applied as primary polycation for layer-by-layer (LBL) assembly of polyelectrolytes. The aim of the present study was to investigate the effect of modification with PEI on the biocompatibility of poly (L-lactide) (PLLA) films. PEI with different molecular weight was immobilized on PLLA by either adsorption or covalent binding. Cell morphologies, immuno-fluorescence staining, cell proliferation by lactate dehydrogenase assay and cell differentiation by alkaline phosphatase assay were utilized to assess the biocompatibility of the modified PLLA using osteoblast cell line MG63. Results revealed that PEI modification remarkably improved cell adhesion, viability, proliferation and function compared with plain PLLA. Hence, PEI-modified PLLA is acceptable as transfection vehicle for engineering of bone and other tissues, or as primary layer to allow LBL assembly to generate biomimetic surface coatings.
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Affiliation(s)
- Zhen-Mei Liu
- Institute of Polymer Science, Zhejiang University, Hangzhou 310027, People's Republic of China.
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Dolatshahi-Pirouz A, Jensen T, Foss M, Chevallier J, Besenbacher F. Enhanced surface activation of fibronectin upon adsorption on hydroxyapatite. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:2971-2978. [PMID: 19437707 DOI: 10.1021/la803142u] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In this study the adsorption characteristics and the structure of fibronectin adsorped on hydroxyapatite (Ha) and a reference gold substrate (Au) is examined by quartz crystal microbalance with dissipation (QCM-D) and atomic force microscopy (AFM) at the following concentrations: 20 microg/mL, 30 microg/mL, 40 microg/mL, 100 microg/mL, 200 microg/mL, and 500 microg/mL. The conformational changes of the fibronectin molecules upon surface binding were examined as well with monoclonal antibody directed against the cell binding-domain (CB domain) of fibronectin. The QCM-D and AFM results show that the fibronectin uptake is larger on Au as compared with Ha regardless of the protein bulk concentration used in the experiment, suggesting that the individual fibronectin molecules in general attach to the surfaces in a more unfolded configuration on Ha. Moreover the dissipation values obtained with QCM-D indicate that the individual fibronectin molecules bind in a more compact and rigid configuration on Au compared to the Ha surface. In particular the monoclonal antibody data show that the CB domain on fibronectin is more available on Ha, where such cell-recognizing abilities are more pronounced at low fibronectin surface coverage. The results demonstrate that the detailed molecular structure of fibronectin and its functional activity depend significantly on both the underlying surface chemistry as well as the fibronectin surface coverage.
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Affiliation(s)
- A Dolatshahi-Pirouz
- Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
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18
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Tang C, Kligman F, Larsen CC, Kottke-Marchant K, Marchant RE. Platelet and endothelial adhesion on fluorosurfactant polymers designed for vascular graft modification. J Biomed Mater Res A 2009; 88:348-58. [PMID: 18286624 DOI: 10.1002/jbm.a.31888] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A prominent failure mechanism of small diameter expanded polytetrafluoroethylene (ePTFE) vascular grafts is platelet-mediated thrombosis. We have designed a surface modification for ePTFE consisting of a self-assembling fluorosurfactant polymer (FSP) bearing biologically active ligands, including adhesive peptides and polysaccharide moieties. The goal of this biomimetic construct is to improve graft hemocompatibility by promoting rapid surface endothelialization, whereas minimizing platelet adhesion. Here we present a direct comparison of platelet and endothelial cell (EC) adhesion to FSPs containing one of three cell-adhesion peptides: cyclic Arg-Gly-Asp-D-Phe-Glu (cRGD), cyclic *Cys-Arg-Arg-Glu-Thr-Ala-Trp-Ala-Cys* (cRRE, *denotes disulfide bond cyclization), linear Gly-Arg-Gly-Asp-Ser-Pro-Ala (RGD), or a polysaccharide moiety: oligomaltose (M-7), later designed to prevent nonspecific protein adhesion. Measurements of soluble peptide-integrin binding indicated that cRRE exhibits very low affinity for the alpha(IIb)beta(3) platelet fibrinogen receptor. Static and dynamic adhesion of washed, activated platelets on FSP-modified surfaces revealed that M-7 and cRRE promote significantly less platelet adhesion compared to RGD and cRGD FSPs, whereas EC adhesion was similar on all peptide FSPs and minimal on M-7 FSP. These results illustrate the potential for ligands presented in a FSP surface modification to selectively adhere ECs with limited platelet attachment.
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Affiliation(s)
- Chad Tang
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Kowalczyńska HM, Nowak-Wyrzykowska M, Kołos R, Dobkowski J, Kamiński J. Semiquantitative evaluation of fibronectin adsorption on unmodified and sulfonated polystyrene, as related to cell adhesion. J Biomed Mater Res A 2008; 87:944-56. [DOI: 10.1002/jbm.a.31868] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Vallières K, Petitclerc E, Laroche G. Covalent grafting of fibronectin onto plasma-treated PTFE: influence of the conjugation strategy on fibronectin biological activity. Macromol Biosci 2007; 7:738-45. [PMID: 17457945 DOI: 10.1002/mabi.200600267] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Surface coating of synthetic materials is often considered to improve biomedical devices biocompatibility. In this study, we covalently bound fibronectin (FN) onto ammonia plasma-treated PTFE via two crosslinkers, namely glutaric anhydride (GA) and sulfosuccinimidyl-4-(p-maleimidophenyl)butyrate (sulfo-SMPB). With respect to clean PTFE, cell adhesion increased markedly on both FN grafted surfaces, although it was twice higher on PTFE-GA-FN than on PTFE-SMPB-FN. ELISA experiments performed with a polyclonal antibody revealed that the amount of FN is identical on both surfaces while monoclonal antibody specific to the RGD binding site clearly demonstrated a greater availability when FN is surface grafted through GA. These results provide evidence of a variation in protein conformation correlated with the surface conjugation strategy.
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Affiliation(s)
- Karine Vallières
- Unité de Biotechnologie et de Bioingénierie, Centre de recherche du CHUQ, Hôpital Saint-François d'Assise, 10 rue de l'Espinay, Québec, Canada, G1L 3L5
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22
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Vallières K, Chevallier P, Sarra-Bournet C, Turgeon S, Laroche G. AFM imaging of immobilized fibronectin: does the surface conjugation scheme affect the protein orientation/conformation? LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:9745-51. [PMID: 17705411 DOI: 10.1021/la701323q] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Covalent grafting of biomolecules could potentially improve the biocompatibility of materials. However, these molecules have to be grafted in an active conformation to play their biological roles. The present work aims at verifying if the surface conjugation scheme of fibronectin (FN) affects the protein orientation/conformation and activity. FN was grafted onto plasma-treated fused silica using two different crosslinkers, glutaric anhydride (GA) or sulfosuccinimidyl 4-(p-maleimidophenyl)butyrate (SMPB). Fused silica was chosen as a model surface material because it presents a roughness well below the dimensions of FN, therefore allowing AFM analyses with appropriate depth resolution. Cell adhesion assays were performed to evaluate the bioactivity of grafted FN. Cell adhesion was found to be higher on GA-FN than on SMPB-FN. Since FN-radiolabeling assays allowed us to rule out a surface concentration effect (approximately 80 ng/cm2 of FN on both crosslinkers), it was hypothesized that FN adopted a more active conformation when grafted via GA. In this context, the FN conformation on both crosslinkers was investigated through AFM and contact angle analyses. Before FN grafting, GA- and SMPB-modified surfaces had a similar water contact angle, topography, and roughness. However, water contact angles of GA-FN and SMPB-FN surfaces clearly show differences in surface hydrophilicity, therefore indicating a dependence of protein organization toward the conjugation strategy. Furthermore, AFM results demonstrated that surface topography and roughness of both FN-conjugated surfaces were significantly different. Distribution analysis of FN height and diameter confirmed this observation as the protein dimensions were significantly larger on GA than SMPB. This study confirmed that the covalent immobilization scheme of biomolecules influences their conformation and, hence, their activity. Consequently, selecting the appropriate conjugation strategy is of paramount importance in retaining molecule bioactivity.
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Affiliation(s)
- Karine Vallières
- Unité de Biotechnologie et de Bioingénierie, Centre de recherche du CHUQ, Hôpital Saint-François d'Assise, 10 rue de l'Espinay, Qué., Canada G1L 3L5
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Larsen CC, Kligman F, Tang C, Kottke-Marchant K, Marchant RE. A biomimetic peptide fluorosurfactant polymer for endothelialization of ePTFE with limited platelet adhesion. Biomaterials 2007; 28:3537-48. [PMID: 17507089 PMCID: PMC2034336 DOI: 10.1016/j.biomaterials.2007.04.026] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Accepted: 04/03/2007] [Indexed: 01/21/2023]
Abstract
Endothelialization of expanded polytetrafluoroethylene (ePTFE) has the potential to improve long-term patency for small-diameter vascular grafts. Successful endothelialization requires ePTFE surface modification to permit cell attachment to this otherwise non-adhesive substrate. We report here on a peptide fluorosurfactant polymer (FSP) biomimetic construct that promotes endothelial cell (EC)-selective attachment, growth, shear stability, and function on ePTFE. The peptide FSP consists of a flexible poly(vinyl amine) backbone with EC-selective peptide ligands for specific cell adhesion and pendant fluorocarbon branches for stable anchorage to underlying ePTFE. The EC-selective peptide (primary sequence: Cys-Arg-Arg-Glu-Thr-Ala-Trp-Ala-Cys, CRRETAWAC) has demonstrated high binding affinity for the alpha(5)beta(1) integrin found on ECs. Here, we demonstrate low affinity of CRRETAWAC for platelets and platelet integrins, thus providing it with EC-selectivity. This EC-selectivity could potentially facilitate rapid in vivo endothelialization and healing without thrombosis for small-diameter ePTFE vascular grafts.
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Affiliation(s)
- Coby C Larsen
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave., Wickenden 309, Cleveland, OH 44106, USA
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Forest PO, Karoum R, Gagnieu CH. Influence of gradual introduction of hydrophobic groups (stearic acid) in denatured atelocollagen on fibroblasts behaviorin vitro. J Biomed Mater Res A 2007; 80:758-67. [PMID: 17133448 DOI: 10.1002/jbm.a.31042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
To prepare new biocompatible hydrophobic collagen films for medical devices, innovative collagen derivatives were synthesized by reaction of the lysyl amino groups of the alpha-chains with activated stearic acid. Different collagens having different substitution degrees were obtained and used to prepare films crosslinked with oxidized glycogen. Their physicochemical surface properties were evaluated, and in vitro assays were performed to analyze the behavior of fibroblasts in contact with the materials. The assays were performed with cells in adhesion and growth phases. The hydrophobic properties increased with the number of stearic acid introduced in the collagen but only in the range of 1-12 stearic acids per molecule. For higher modifications a decrease of hydrophoby was observed. All the films induced a decrease of cells growth and adhesion but without cytotoxicity. These effects were more pronounced for the collagen containing about eight stearic acid residues. Cells behavior on modified collagens films seems to be related to the chemical groups exposed on the surface of the films. Indeed, the surface chemistry directly influences the adsorption of adhesion proteins and modulates their conformation therefore modifying the cell adhesion.
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Affiliation(s)
- P O Forest
- Faculté de Pharmacie de Lyon, Laboratoire des Biomatériaux, Dispositifs Médicaux et Remodelages Matriciels,UMR MA, 8 avenue Rockefeller, 69390 Cedex 08 Lyon, France
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FUSE Y, HIRATA I, KURIHARA H, OKAZAKI M. Cell Adhesion and Proliferation Patterns on Mixed Self-assembled Monolayers Carrying Various Patios of Hydroxyl and Methyl Groups. Dent Mater J 2007; 26:814-9. [DOI: 10.4012/dmj.26.814] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Mitsi M, Hong Z, Costello CE, Nugent MA. Heparin-mediated conformational changes in fibronectin expose vascular endothelial growth factor binding sites. Biochemistry 2006; 45:10319-28. [PMID: 16922507 DOI: 10.1021/bi060974p] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Regulation of angiogenesis involves interactions between vascular endothelial growth factor (VEGF) and components of the extracellular matrix, including fibronectin and heparan sulfate. In the present study, we identified two classes of VEGF binding sites on fibronectin. One was constitutively available whereas the availability of the other was modulated by the conformational state of fibronectin. Atomic force microscopy studies revealed that heparin and hydrophilic substrates promoted the extended conformation of fibronectin, leading to increased VEGF binding. The ability of heparin to enhance VEGF binding to fibronectin was dependent on the chemical composition and chain length of heparin, since long (>22 saccharides) heparin chains with sulfation on the 6-O and N positions of glucosamine units were required for full activity. Treatment of the complex endothelial extracellular matrix with heparin also increased VEGF binding, suggesting that heparin/heparan sulfate might regulate VEGF interactions within the extracellular matrix by controlling the structure and organization of fibronectin matrices.
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Affiliation(s)
- Maria Mitsi
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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Bae YH, Johnson PA, Florek CA, Kohn J, Moghe PV. Minute changes in composition of polymer substrates produce amplified differences in cell adhesion and motility via optimal ligand conditioning. Acta Biomater 2006; 2:473-82. [PMID: 16793356 DOI: 10.1016/j.actbio.2006.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 03/15/2006] [Accepted: 04/17/2006] [Indexed: 01/12/2023]
Abstract
We explored the interplay between substratum chemistry of polymeric materials and surface-adsorbed ligand concentration (human plasma fibronectin) in the control of cell adhesion and cell motility. We found that small changes in the chemical composition of a polymeric substratum had different effects on cellular motility--depending on the concentration of preadsorbed fibronectin. We used two tyrosine-derived polyarylates, poly(DTD diglycolate) and poly(DTD glutarate), as substrata for the seeding of NIH-3T3 fibroblasts. The only compositional difference between the two test polymers was that one single oxygen atom in the polymer backbone of poly(DTD diglycolate) had been substituted by a methylene group in the backbone of poly(DTD glutarate), The two polymers had closely matched hydrophobicity and physical properties. Flat, spin-coated surfaces of these polymers were pretreated with different concentrations of human plasma fibronectin (0-20 microg/ml). After seeding with NIH-3T3 fibroblasts, we examined the adhesion and motility behavior of these cells. We found that NIH-3T3 fibroblasts migrated significantly faster on poly(DTD diglycolate), but only when the polymer surfaces were pretreated with intermediate concentrations of fibronectin. Only at these intermediate levels of ligand conditioning, did the presence of an extra oxygen atom in the backbone of poly(DTD diglycolate) relative to poly(DTD glutarate) (i) alter the overall organization/concentration of the fibronectin; (ii) weaken cell attachment strength and inhibited excessive cell spreading; and (iii) promote cell motility kinetics. These findings indicate that the biological effect of minute changes in substratum chemistry is critically dependent on the level of surface-adsorbed cell-binding ligands.
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Affiliation(s)
- Yong Ho Bae
- Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, NJ 08854, USA
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Iucci G, Rossi L, Rosato N, Savini I, Duranti G, Polzonetti G. The interaction of the polyphenylacetylene surface with biological environments studied by XPS, RAIRS and biological tests. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2006; 17:779-87. [PMID: 16932858 DOI: 10.1007/s10856-006-9835-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2005] [Accepted: 10/21/2005] [Indexed: 05/11/2023]
Abstract
A pi-conjugated polymer, polyphenylacetylene or PPA, has been tested for its possible applications as biosensor or biomaterial. Protein adsorption was investigated by incubating PPA films in solutions of bovine serum albumin (BSA) dissolved in phosphate buffer (PBS) having increasing protein concentration. Investigations on the PPA films were carried out by means of two surface analysis techniques, X-ray photoelectron spectroscopy (XPS) and reflection-absorption infrared spectroscopy (RAIRS). Desorption of BSA from the PPA surface was also investigated. Finally, the cytototoxicity of the PPA surface was checked by measuring viability and proliferation of lymphoma macrophages and SAOS osteoblasts grown in the presence of the polymer.
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Affiliation(s)
- G Iucci
- Dipartimento di Fisica E. Amaldi, Universit à Roma Tre, Unità INFM, INSTM, and CISDiC, Via della Vasca Navale 84, 00146, Roma.
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Larsen CC, Kligman F, Kottke-Marchant K, Marchant RE. The effect of RGD fluorosurfactant polymer modification of ePTFE on endothelial cell adhesion, growth, and function. Biomaterials 2006; 27:4846-55. [PMID: 16762410 PMCID: PMC2048534 DOI: 10.1016/j.biomaterials.2006.05.009] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Accepted: 05/10/2006] [Indexed: 11/28/2022]
Abstract
We have synthesized and characterized a novel peptide fluorosurfactant polymer (PFSP) modification that facilitates the adhesion and growth of endothelial cells on expanded polytetrafluoroetheylene (ePTFE) vascular graft material. This PFSP consists of a poly(vinyl amine) (PVAm) backbone with integrin binding Arg-Gly-Asp (RGD) peptides and perfluorocarbon pendant branches for adsorption and stable adhesion to underlying ePTFE. Aqueous PFSP solution was used to modify the surface of fluorocarbon substrates. Following subconfluent seeding, endothelial cell (EC) adhesion and growth on PFSP was assessed by determining cell population at different time points. Spectroscopic results indicated successful synthesis of PFSP. PFSP modification of ePTFE reduced the receding water contact angle measurement from 120 degrees to 6 degrees , indicating successful surface modification. Quantification of cell population demonstrated reduced EC attachment efficiency but increased growth rate on RGD PFSP compared with fibronectin (FN). Actin staining revealed a well-developed cytoskeleton for ECs on RGD PFSP indicative of stable adhesion. Uptake of acetylated low-density lipoprotein and positive staining for VE-Cadherin confirm EC phenotype for adherent cells. Production of prostacyclin, a potent antiplatelet agent, was equivalent between ECs on FN and RGD PFSP surfaces. Our results indicate successful synthesis and surface modification with PFSP; this is a simple, quantitative, and effective approach to modifying ePTFE to encourage endothelial cell attachment, growth, and function.
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Affiliation(s)
- Coby C. Larsen
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave., Wickenden 319, Cleveland, OH 44106, USA
| | - Faina Kligman
- Department of Clinical Pathology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Kandice Kottke-Marchant
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave., Wickenden 319, Cleveland, OH 44106, USA
- Department of Clinical Pathology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Roger E. Marchant
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave., Wickenden 319, Cleveland, OH 44106, USA
- *Corresponding author. Tel.: +1-216-368-3005; fax: +1-216-368-4969 E-mail address: (R.E. Marchant)
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Influence of Molecular Weight and Crystallinity of Poly(L-Lactic Acid) on the Adhesion and Proliferation of Human Osteoblast Like Cells. ACTA ACUST UNITED AC 2006. [DOI: 10.4028/www.scientific.net/msf.514-516.1020] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The molecular weight and crystallinity of systems based on poly(L-lactic acid) PLLA is an important issue as it can influence, besides the general physical properties of the polymer, the patterns of cell adhesion, proliferation and cell morphology. The objective of the present study was to evaluate how crystallinity and molecular weight of PLLA influence the referred parameters. Four conditions were tested: low molecular weight amorphous and semi-crystalline PLLA disks, and
high molecular weight amorphous and semi-crystalline PLLA disks, obtained from hot press. The thermal properties of the studied materials were accessed by differential scanning calorimetry. For the cell culture studies a human osteosarcoma cell line (SaOS-2) was chosen. Disks were immersed in a cell suspension containing 5x104 cells/ml and kept in culture for periods up to two weeks. Cell
viability and proliferation of SaOS-2 cells was assessed by MTS test and a total protein assay, respectively. The adhesion and morphology of SaOS-2 cells on PLLA disks was assessed by scanning electronic microscopy. Results showed that cell viability was not affected by the different tested conditions. However, cell proliferation was increased in the high molecular weight amorphous samples and cells seemed to have higher adhesion patterns on semi-crystalline samples.
This is probably happening due to different rates of integrin interaction with the substrate leading to different patterns of focal adhesion points formation.
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31
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Allen LT, Tosetto M, Miller IS, O'Connor DP, Penney SC, Lynch I, Keenan AK, Pennington SR, Dawson KA, Gallagher WM. Surface-induced changes in protein adsorption and implications for cellular phenotypic responses to surface interaction. Biomaterials 2006; 27:3096-108. [PMID: 16460797 DOI: 10.1016/j.biomaterials.2006.01.019] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2005] [Accepted: 01/13/2006] [Indexed: 12/25/2022]
Abstract
Understanding external factors that determine cellular phenotypic responses is of key interest in the field of biomaterials. Currently, material surface characteristics, protein adsorption and cellular phenotypic responses are all considered to be interrelated and ultimately determine the biocompatibility of materials. The exact nature of the relationship between these distinct, yet related, phenomena still remains to be elucidated. Through the use of a series of thermoresponsive N-isopropylacrylamide-based co-polymer films, we aimed to shed light on the relationship between surface hydrophobicity, protein adsorption and subsequent cellular response. Despite changes in co-polymer hydrophobicity mediated by altered ratios of constituent monomers, differential cellular response was only apparent in the presence of serum. Co-polymer films displayed alterations with respect to the amount of protein adsorbed on the surface, with individual serum proteins (albumin and fibronectin) displaying contrasting adsorption characteristics. Changes in protein adsorption corresponded to changes in cell adhesion, cytoskeletal organisation and cell morphology, as well as to changes in cell movement and intracellular signalling events. Examination of focal adhesion kinase (FAK), and extracellular signal-regulated kinase (ERK 1/2), important mediators of adhesion and growth factor-related signalling events, revealed a comparative reduction in phosphorylation of these signalling proteins in cells grown on co-polymers in comparison to those cultured on tissue culture polystyrene (TCP; used as a control surface). We also associated surface-mediated phenotypic alterations of cells grown on TCP and co-polymer films with particular changes in gene expression. These results indicate that cellular response to interaction with our series of co-polymer films is determined by the surface-adsorbed protein layer, which in turn is determined by the changing surface chemistry as the ratio of the co-monomers is altered.
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Affiliation(s)
- Lorcan T Allen
- UCD School of Biomolecular and Biomedical Science, Centre for Molecular Medicine, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
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Curran JM, Chen R, Hunt JA. Controlling the phenotype and function of mesenchymal stem cells in vitro by adhesion to silane-modified clean glass surfaces. Biomaterials 2005; 26:7057-67. [PMID: 16023712 DOI: 10.1016/j.biomaterials.2005.05.008] [Citation(s) in RCA: 168] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Accepted: 05/06/2005] [Indexed: 11/21/2022]
Abstract
The behaviour of human mesenchymal stem cells (hMSC) when cultured in contact with a range of silane-modified surfaces was examined to determine if changing the surface chemistry affected the early differentiation potential of mesenchymal stem cells in vitro over a 7-day period. Cells were cultured for 1 and 7 days in direct contact with glass which had been functionalized by surface treatment to provide a range of different surfaces: -CH(3), -NH(2), -SH, -OH, and -COOH modified surfaces and a clean glass reference (TAAB). Viable cell adhesion was quantified by Lactate Dehydrogenase assay, and morphology and viability was qualitatively evaluated using calcein AM, ethidium homodimer, cytoskeletal (F Actin), extra-cellular matrix (fibronectin and vitronectin) and Hoechst staining (nucleus). The expression of selected differentiation markers, Collagen II (chondrocytes), CBFA1 (bone transcription factor), Collagen I (MSC marker) and TGF-beta3 (extra-cellular matrix production) was determined using real time polymerase chain reaction. The expression of ornithine decarboxylase was evaluated as a marker of proliferation. Surfaces of the -NH(2) group demonstrated the greatest level of cell adhesion by the 7-day period, and mRNA expression profiles indicated osteogenic differentiation, increased CBFA1 and decreased Collagen II expression. Cells cultured in contact with the -COOH surfaces displayed different cell morphologies, fibronectin and vitronectin spatial distributions compared with the cells in contact with the -NH(2) surfaces, in addition to an increase in Collagen II expression, indicative of chondrogenic differentiation. The modifications to the surface chemistry of glass did affect cell behaviour, both in terms of viable cell adhesion, morphology and profiles of mRNA expression, providing the means to alter the differentiation potential of the MSCs.
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Affiliation(s)
- J M Curran
- UK Centre for Tissue Engineering, Clinical Engineering, University of Liverpool.
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Gauvreau V, Laroche G. Micropattern Printing of Adhesion, Spreading, and Migration Peptides on Poly(tetrafluoroethylene) Films To Promote Endothelialization. Bioconjug Chem 2005; 16:1088-97. [PMID: 16173784 DOI: 10.1021/bc049717s] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report here the development of an original multistep micropatterning technique for printing peptides on surfaces, based on the ink-jet printer technology. Contrary to most micropatterning methods used nowadays, this technique is advantageous because it allows displaying 2D-arrays of multiple biomolecules. Moreover, this low cost procedure allies the advantages of computer-aided design with high flexibility and reproducibility. A Hewlett-Packard printer was modified to print peptide solutions, and Adobe Illustrator was used as the graphic-editing software to design high-resolution checkerboard-like micropatterns. In a first step, PTFE films were treated with ammonia plasma to introduce amino groups on the surface. These chemical functionalities were reacted with heterobifunctional cross-linker sulfo-succinimidyl 4-(N-maleimidomethyl)cycloexane-1-carboxylate (S-SMCC) to allow the subsequent surface covalent conjugation of various cysteine-modified peptides to the polymer substrate. These peptidic molecules containing RGD and WQPPRARI sequences were selected for their adhesive, spreading, and migrational properties toward endothelial cells. On one hand, our data demonstrated that the initial cell adhesion does not depend on the chemical structure and combination of the peptides covalently bonded either through conventional conjugation or micropatterning. On the other hand, spreading and migration of endothelial cells is clearly enhanced while coconjugating the GRGDS peptide in conjunction with WQPPRARI. This behavior is further improved by micropatterning these peptides on specific areas of the polymer surface.
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Affiliation(s)
- Virginie Gauvreau
- Unité de Biotechnologie et de Bioingénierie, Centre de Recherche de l'Hôpital Saint-François d'Assise, CHUQ, 10 rue de l'Espinay, Québec, Québec, Canada, G1L 3L5
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Tunc S, Maitz MF, Steiner G, Vázquez L, Pham MT, Salzer R. In situ conformational analysis of fibrinogen adsorbed on Si surfaces. Colloids Surf B Biointerfaces 2005; 42:219-25. [PMID: 15893222 DOI: 10.1016/j.colsurfb.2005.03.004] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2004] [Revised: 03/23/2005] [Accepted: 03/24/2005] [Indexed: 10/25/2022]
Abstract
Fibrinogen is a major plasma protein. Previous investigations of structural changes of fibrinogen due to adsorption are mostly based on indirect evidence after its desorption, whereas our measurements were performed on fibrinogen in its adsorbed state. Specific enzyme-linked immunosorption experiments showed that the amount of adsorbed fibrinogen increased as the surface became more hydrophobic. Atomic force microscopy (AFM) investigations revealed the trinodular shape of fibrinogen molecules adsorbed on hydrophilic surfaces, whereas all of the molecules appeared globular on hydrophobic surfaces. The distribution of secondary structures in adsorbed fibrinogen was quantified by in situ Fourier-transform infrared (FTIR) analysis. Substrates of identical chemical bulk composition but different surface hydrophobicity permit direct comparison among them. Adsorption properties of fibrinogen are different for each degree of hydrophobicity. Although there is some increase of turn structure and decrease of beta-sheet structure, the secondary structure of adsorbed fibrinogen on hydrophilic surface turned out to be rather similar to that of the protein in solution phase with a major alpha-helix content. Hydrophilic surfaces exhibit superior blood compatibility as required for medical applications.
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Affiliation(s)
- Sibel Tunc
- Institute of Analytical Chemistry, Dresden University of Technology, 01062 Dresden, Germany
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Toworfe GK, Composto RJ, Adams CS, Shapiro IM, Ducheyne P. Fibronectin adsorption on surface-activated poly(dimethylsiloxane) and its effect on cellular function. ACTA ACUST UNITED AC 2004; 71:449-61. [PMID: 15481053 DOI: 10.1002/jbm.a.30164] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This article reports that surface modification of poly(dimethylsiloxane) (PDMS) influences fibronectin (Fn) adsorption and enhances cell attachment. Controlled adsorption of Fn on chemically activated polymer substrates is known to influence cellular function. Thin films of PDMS were spun cast on silicon wafers to obtain homogeneous and molecularly smooth surfaces. The films were made hydrophilic by exposure to ultraviolet ozone activation (PDMS*). The films then were characterized by contact angle goniometry, ellipsometry, atomic force microscopy (AFM), Rutherford backscattering spectrometry and X-ray photoelectron spectroscopy. Contact angle measurements indicated higher hydrophobicity of the nonactivated PDMS substrates than PDMS*. AFM scans of the substrates indicated higher surface roughness of PDMS* (Ra = 0.55 nm) than PDMS (Ra = 0.25 nm). Although Fn surface density (Gamma) was slightly higher on PDMS than on PDMS*, due to hydrophobic interactions between substrate and Fn, cell function was greatly enhanced on the Fn-coated PDMS* (PDMS*-Fn) than on PDMS (PDMS-Fn). Higher attachment of MC3T3-E1 osteoblast-like cells was observed on PDMS*-Fn than on PDMS-Fn. Moreover, cell spreading and cytoskeleton organization after 72 h was clearly favored on the Fn-coated PDMS* surfaces.
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Affiliation(s)
- George K Toworfe
- Center for Bioactive Materials and Tissue Engineering, Department of Bioengineering, University of Pennsylvania School of Engineering and Applied Science, 120 Hayden Hall, 3320 Smith Walk, Philadelphia, Pennsylvania 19104-6392, USA.
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Pompe T, Kobe F, Salchert K, Jørgensen B, Oswald J, Werner C. Fibronectin anchorage to polymer substrates controls the initial phase of endothelial cell adhesion. J Biomed Mater Res A 2004; 67:647-57. [PMID: 14566809 DOI: 10.1002/jbm.a.10130] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Early stages of the adhesion of human endothelial cells onto a set of smooth polymer films were analyzed to reveal the modulation of cell-matrix interactions by the physicochemical constraints of predeposited fibronectin (FN). Hydrophobic and hydrophilic polymer substrates, consisting of poly(octadecene-alt-maleic anhydride) and poly(propene-alt-maleic anhydride) films, were coated with similar amounts of FN at conditions of either covalent or noncovalent immobilization. The well-defined substrates permit variation of the anchorage of FN at invariant topography, pliability, and molecular composition. Although all of the compared FN coatings were effective in stimulating attachment of endothelial cells, the initial formation of cell-matrix adhesions was found to be controlled by the type of interaction between predeposited FN and the underlying substrate. Covalent linkage and hydrophobic interactions of the predeposited FN with the polymer films interfered with the rapid generation of focal and fibrillar adhesions. It was demonstrated that this was caused by the fact that only weakly bound FN could become readily reorganized by the adherent cells. Upon prolonged culture periods at standard cell culture conditions, secretion and deposition of organized extracellular matrix by the attached cells was found to balance out the differences of the substrates.
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Affiliation(s)
- Tilo Pompe
- Institute of Polymer Research Dresden & The Max Bergmann Center of Biomaterials Dresden, Hohe Str. 6, 01069 Dresden, Germany
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Cheuk BLY, Cheng SWK. Differential expression of integrin alpha5beta1 in human abdominal aortic aneurysm and healthy aortic tissues and its significance in pathogenesis. J Surg Res 2004; 118:176-82. [PMID: 15100006 DOI: 10.1016/s0022-4804(03)00351-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2003] [Indexed: 12/31/2022]
Abstract
BACKGROUND Abdominal aortic aneurysm (AAA) is a common aged disease of human aorta with increasing incidence. It is characterized by dramatic vascular remodeling via proteolysis and degradation of matrix proteins. Integrins are important cellular receptors for matrix proteins, which may have an association with pathological remodeling. The present study was undertaken to analyze the expression of integrin subunits in human aneurysmal aortas and with healthy aortic tissues as controls. MATERIALS AND METHODS The expression of integrin genes in AAA specimens and healthy human aortic tissues was detected by RT-PCR technique. The correlation of variation and distribution of smooth muscle cells (SMCs) and integrin protein expression in the corresponding tissues were studied immunohistochemically. RESULTS The gene transcripts coding for integrin alpha4, alpha5, alphaV, beta1, beta3, beta5, and beta6 subunits were constitutively expressed in the normal aortas. Only gene expressions of integrin alpha5 and beta1 were significantly decreased by 81% and 85%, respectively, in AAA specimens (P < 0.005) when compared with healthy aortic specimens. No age dependence of the expression of integrin alpha5beta1 genes was found. Significant reduction of medial SMC density was confirmed in corresponding AAA compared with control aortas. Immunoreactivity of integrin alpha5beta1 receptor was found to be exclusively localized within the medial layer of the parallel normal aortic sections, whereas this protein was absent in the destructive media of aneurysmal aortic sections. CONCLUSIONS The marked decrease in integrin alpha5beta1 expressions was unique to aneurysmal aortic tissues and correlated to a decrease in density of SMCs, which are the major cells in maintaining the structure stability of normal aortas. As integrin alpha5beta1 specifically binds fibronectin and collagen, those results may suggest that the absence of integrin alpha5beta1 activity impair matrix protein attachment and alter the architecture in aortic media thereby lead to the deformity of aorta and aneurysm formation.
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Affiliation(s)
- Bernice L Y Cheuk
- Department of Surgery, University of Hong Kong Medical Centre, Queen Mary Hospital, Hong Kong, China
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Kowalczyńska HM, Nowak-Wyrzykowska M, Kołos R, Dobkowski J, Kamiński J. Fibronectin adsorption and arrangement on copolymer surfaces and their significance in cell adhesion. J Biomed Mater Res A 2004; 72:228-36. [PMID: 15625681 DOI: 10.1002/jbm.a.30238] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The adsorption of fibronectin (FN) to (styrene/methyl methacrylate) copolymer surfaces, both sulfonated (hydrophilic) and nonsulfonated (hydrophobic), was studied by means of the radioisotope (125I-FN) and ELISA assays; the latter employed monoclonal antibodies. It was found that the radioiodination-derived isotherms did not follow the Langmuir-type adsorption law within the FN concentration range studied; rather, a quasi-linear FN surface density versus bulk concentration dependence was observed. These isotherms, and our recent ELISA measurements with polyclonal antibodies, allowed us to estimate saturative FN surface densities, which were, within the experimental error, similar on both types of surfaces. This suggested the amount of adsorbed FN to be not responsible for observed differences in leukaemia L1210 cell adhesion (FN-coated sulfonated surfaces are far more pro-adhesive than their nonsulfonated analogues). The presumption that these differences are induced by changes in the FN arrangement was confirmed by the use of monoclonal antibodies directed against distinct FN domains, and by the blocking of alpha5beta1 integrin receptor with the synthetic Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP) peptide. The RGD sequence located within the FN cell-binding domain seems to be masked in the structure adopted on nonsulfonated surfaces, which hinders the integrin-ligand interaction.
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Affiliation(s)
- Hanna M Kowalczyńska
- Department of Biophysics and Biomathematics, Medical Centre for Postgraduate Education, ul. Marymoncka 99, 01-813 Warszawa, Poland.
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Salchert K, Pompe T, Sperling C, Werner C. Quantitative analysis of immobilized proteins and protein mixtures by amino acid analysis. J Chromatogr A 2003; 1005:113-22. [PMID: 12924786 DOI: 10.1016/s0021-9673(03)00932-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Biomolecular surface engineering of materials often requires precise, versatile and efficient quantification of immobilized proteins at solid surfaces. Acidic hydrolysis of surface-bound proteins and subsequent HPLC analysis of fluorescence-derivatized amino acids were adapted and critically evaluated for that purpose. Contaminations and concentration-dependent amino acid retrieval during HPLC were found to influence the accuracy of the method. In addition to the choice of adequate conditions for hydrolysis, derivatization and chromatographic separation extensions of the data evaluation were suggested to improve the accuracy of the approach when applied to single protein systems: comparing the experimentally obtained amino acid ratio to the protein constitution enabled to identify the properly separated and detected amino acids. Those amino acids were selected for a more precise calculation of the amount of immobilized protein. To further increase the accuracy of the method, the retrieval of amino acids corresponding to protein amounts in the range between 0.5 and 4.0 microg was analyzed for a variety of proteins of interest to derive protein-specific correction factors. The evaluation of amino acid data was furthermore applied to quantify binary protein mixtures at similar settings. This method was proven useful to detect the composition of protein mixtures throughout a wide range of absolute and relative concentrations.
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Affiliation(s)
- Katrin Salchert
- Institut für Polymerforschung Dresden e.V. Abteilung Biokompatible Materialien, Hohe Str. 6, 01069 Dresden, Germany
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Kowalczyńska HM, Inkielman M, Nowak-Wyrzykowska M, Stołowska L, Doroszewski J. Interaction of L1210 cells with sulfonated polystyrene in the absence of serum: adhesion and three-dimensional cell shape. Colloids Surf B Biointerfaces 2003. [DOI: 10.1016/s0927-7765(03)00086-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Wang DA, Feng LX, Ji J, Sun YH, Zheng XX, Elisseeff JH. Novel human endothelial cell-engineered polyurethane biomaterials for cardiovascular biomedical applications. J Biomed Mater Res A 2003; 65:498-510. [PMID: 12761841 DOI: 10.1002/jbm.a.10533] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A tri-block coupling-polymer composed of 4,4'-methylenediphenyl diisocyanate and poly (ethylene oxide) (PEO), abbreviated MPEO, was used as the template surface-modifying additive (SMA), based on which selected amino acids (lysine, arginine, glycin, and aspartic acid) and RGD peptide were respectively conjugated as functional endgroups of the PEO spacer-arms through sulfonyl chloride-activation routes. After the immobilization of biofunctional factors, the SMA-MPEO derivatives were noncovalently introduced onto the biomedical poly(ether urethane) (PEU) surfaces by physical blending methods. The SMA synthesis and PEU surface modification were monitored and analyzed by nuclear magnetic resonance spectroscopy, attenuated total reflection-infrared spectroscopy, and X-ray photoelectron spectroscopy. The human umbilical vein endothelial cells (HUVECs) were collected and harvested manually by collagenase digestion. The cell culture was performed respectively on the MPEO derivative-modified PEU surfaces and also on the surfaces of the commercially available polystyrene cell-culture plates (TCPS) for control. The cell adhesion rates and cell proliferation rates of the in vitro cultivated HUVEC were measured using flow cytometry. The individual cell viability rates were determined with MTT assay. The cell morphologies of the living HUVECs were investigated by optical inverted microscopy, and more detailed information was acquired from scanning electrical microscopy. The results indicated that the efficacy of SMA functional endgroups was the dominant factor for HUVEC compatibility; the proper-sized PEO spacers (M(w) 2 k) could support and mobilize the functional endgroups, optimizing the surface (interface) environment for the cell growth. As the endgroups of the SMA-MPEO derivatives and the bio-functional factors, the basic amino acids (lysine and arginine) demonstrated similar performances to that of the widely acknowledged cell growth-promoter, RGD peptide, which were superior to TCPS. Therefore, these MPEO derivative-modified PEU materials are promising to serve as novel polymeric permanent implants or interventional devices for cardiovascular biomedical applications.
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Affiliation(s)
- Dong-An Wang
- Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China.
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