Adsorption of plasma proteins and fibronectin on poly(hydroxylethyl methacrylate) brushes of different thickness and their relationship with adhesion and migration of vascular smooth muscle cells.

J. Deng,J. Zhu,T. Ren,Z. Mao,C. Gao

doi:10.1093/rb/rbu008

Abstract

The surface-grafted poly(hydroxylethyl methacrylate) (PHEMA) molecules were demonstrated to show a brush state regardless of their molecular length (molecular weight). Adsorption of proteins from 10% fetal bovine serum (FBS), fibronectin (Fn) and bovine serum albumin (BSA) was quantified by ellipsometry, revealing that the amounts of FBS and Fn decreased monotonously along with the increase of PHEMA thickness, whereas not detectable for BSA when the PHEMA thickness was larger than 6 nm. Radio immunoassay found that the adsorption of Fn from 10% FBS had no significant difference regardless of the PHEMA thickness. However, ELISA results showed that the Arg-Gly-Asp (RGD) activity of adsorbed Fn decreased with the increase of PHEMA thickness. By comparison of cellular behaviors of vascular smooth muscle cells (VSMCs) being cultured in vitro in the normal serum-containing medium and the Fn-depleted serum-containing medium, the significant role of Fn on modulating the adhesion and migration of VSMCs was verified. Taking account all the results, the Fn adsorption model and its role on linking the biomaterials surface to the VSMCs behaviors are proposed.

Highlights

The cell migration plays a critical role in a variety of pathological and physiological processes, such as embryonic development, cancer metastasis, blood vessel formation and remolding, tissue regeneration, immune surveillance and inflammation [1, 2]
The grafting density of poly(hydroxylethyl methacrylate) (PHEMA) brushes (r) was nearly 0.15/nm2, and the 3, 6, 15 and 20 nm PHEMA were all in a brush state
The amounts of adsorbed Fn and fetal bovine serum (FBS) decreased monotonously along with the increase of thickness of PHEMA brushes, whereas adsorption of bovine serum albumin (BSA) was not detectable when the thickness of PHEMA brushes was larger than 6 nm by ellipsometry

Summary

Introduction

The cell migration plays a critical role in a variety of pathological and physiological processes, such as embryonic development, cancer metastasis, blood vessel formation and remolding, tissue regeneration, immune surveillance and inflammation [1, 2]. Many efforts have been paid to study the cell migration on the gradient biomaterials. The surfaces with chemical and physical gradients have been prepared and their influences on the cell migration have been investigated. Immobilization of various biomolecules such as extracellular matrix proteins (fibronectin (Fn) [3], laminin [4] and collagen [5, 6]), and growth factors (epidermal growth factor (EGF) [7], basic fibroblast growth factor (bFGF) [8] and vascular endothelial growth factor (VEGF) [9]), and RGD on gradient biomaterials can guide cell migration directionally as well. The physical signal plays an important role in modulating the cell migration.

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Discussion

Conclusion