title: The effect of elastomer chain flexibility on protein adsorption.
abstract: Cells are known to respond differently when grown on materials of varying stiffness. However, the mechanism by which a cell senses substrate stiffness is unknown. Lower crosslink density elastomers formed from acrylated star-poly(d,l lactide-co-ϵ-caprolactone) have previously been shown to support higher smooth muscle cell proliferation in in vitro culture. This difference in growth was hypothesized to be due to differences in protein adsorption that resulted from differences in polymer chain mobility at the surface. Therefore, layer mass and viscoelastic properties were measured for HSA, IgG, fibronectin, vitronectin, and serum supplemented media adsorbed to elastomers of two crosslink densities. Significantly more fibronectin adsorbed to the lower crosslink density surface while significantly more IgG adsorbed to the higher crosslink density surface. Furthermore, differences in fibronectin and IgG layer shear moduli were observed, suggesting that there was a difference in the conformation of the adsorbed protein. ATR-FTIR analysis showed that the lower crosslink density elastomer absorbed more surface water. The increased amount of water may cause greater entropic gains upon protein adsorption to the lower crosslink density surface, which increases total protein adsorption from serum and may cause differences in protein conformation and thus cell behavior.
authors.affiliation: Department of Chemical Engineering, Queen's University, Kingston, ON K7L 3N6, Canada.
authors.forename: Moira C
authors.initials: MC
authors.lastname: Vyner
authors.forename: Lina
authors.initials: L
authors.lastname: Liu
authors.forename: Heather D
authors.initials: HD
authors.lastname: Sheardown
authors.forename: Brian G
authors.initials: BG
authors.lastname: Amsden
mesh_terms: D016475:3T3 Cells; D000327:Adsorption; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002448:Cell Adhesion; D020724:Elastomers / Q000737:chemistry*; D005353:Fibronectins / Q000302:isolation & purification; D006801:Humans; D007074:Immunoglobulin G / Q000302:isolation & purification; D051379:Mice; D011091:Polyesters / Q000737:chemistry*; D011506:Proteins / Q000302:isolation & purification*; D012709:Serum Albumin / Q000302:isolation & purification; D013499:Surface Properties; D019096:Vitronectin / Q000302:isolation & purification
chemical_list: D001672:Biocompatible Materials; D020724:Elastomers; D005353:Fibronectins; D007074:Immunoglobulin G; D011091:Polyesters; D011506:Proteins; D012709:Serum Albumin; D019096:Vitronectin; C062968:lactide-caprolactone copolymer
keywords: Cell adhesion; Crosslink density; Elastomer; Polymer chain mobility; Protein adsorption