Myoblast proliferation and differentiation on fibronectin-coated self assembled monolayers presenting different surface chemistries

Biomaterial surface properties modulate protein adsorption and cell adhesion to elicit diverse cellular responses in biomedical and biotechnological applications. We used alkanethiol self-assembled monolayers presenting well-defined chemistries (OH, CH3, NH2, and COOH) to analyze the effects of surface chemistry on myoblast proliferation and differentiation. Surfaces were pre-coated with equivalent densities of fibronectin. C2C12 skeletal myoblasts exhibited surface-dependent differences in cell proliferation (COOH=NH2>CH3=OH). Myogenin and troponin T gene expression levels were up-regulated on CH3 and OH surfaces compared to other chemistries. Furthermore, immunostaining for sarcomeric myosin revealed surface chemistry-dependent differences in myogenic differentiation following the pattern OH>CH3>NH2=COOH. Immunostaining analyses of integrin subunits demonstrated surface chemistry-dependent differences in integrin binding to adsorbed fibronectin. OH and CH3 surfaces supported selective binding of α5β1 integrin while the COOH and NH2 functionalities displayed binding of both α5β1 and αVβ3 Myogenic differentiation correlated with differences in integrin binding; surface chemistries that supported selective binding of α5β1 displayed enhanced differentiation. Finally, blocking β1, but not β3, integrins inhibited differentiation, implicating specific integrins in the differentiation process. These results demonstrate that surface chemistry modulates myoblast proliferation and differentiation via differences in integrin binding to adsorbed fibronectin.