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Gradient substrate assembly for quantifying cellular response to biomaterials
Author(s) -
Mei Ying,
Elliott John T.,
Smith Jack R.,
Langenbach Kurt J.,
Wu Tao,
Xu Chang,
Beers Kathryn L.,
Amis Eric J.,
Henderson Lori
Publication year - 2006
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.30883
Subject(s) - materials science , fibronectin , polymer , substrate (aquarium) , methacrylate , biophysics , protein adsorption , adhesion , cell adhesion , adsorption , ellipsometry , density gradient , chemical engineering , analytical chemistry (journal) , nanotechnology , polymerization , cell , composite material , thin film , chromatography , chemistry , biochemistry , oceanography , organic chemistry , biology , engineering , geology , physics , quantum mechanics
Using quantitative fluorescence microscopy in conjunction with a method of gradient substrate assembly established in their group, the authors were able to introduce and measure reproducible changes in cellular morphology and cell density by manipulating polymer grafting density. The mechanism behind this change in cellular behavior was explained by a semiempirical, geometric model that describes the effect of the spatial distribution of the polymer on protein attachment. A 10‐fold increase in graft density of poly(2‐hydroxyethyl methacrylate) [PHEMA] along the surface of a gradient sample, preexposed to bovine fibronectin, caused a change in the size of fibroblasts on the surface (i.e., cell spreading) from (1238 ± 704) to (377 ± 216) μm 2 . The results were in quantitative agreement with those obtained on three separate gradient samples. Both cellular response and fibronectin adsorption (as measured via ellipsometry) were found to vary sigmoidally with graft density of PHEMA, demonstrating the high degree of correlation between the two phenomena. A simple, rigid‐disk model accounting for the surface coverage of PHEMA was able to predict the amount of adsorbed fibronectin with a correlation coefficient of 0.97. Maximal cell adhesion and cell spreading were found to occur at fibronectin surface densities of 50 and 100 ng/cm 2 , respectively. The results demonstrate the role of gradient substrate assembly as a method for quantifying the relationship between protein and cellular response to technologically relevant polymeric materials. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006