Fabrication of novel collagen-silica hybrid membranes with tailored biodegradation and strong cell contact guidance ability

The fabrication of novel collagen-silica hybrid membranes with tailored biodegradation and strong cell contact guidance ability is reported in the present study. Collagen-silica hybrids were first synthesized by reacting 3-glycidoxypropyltrimethoxysilane (GPTMS), which functioned as both the cross-linker and the silica source, with acid-soluble type I porcine collagen monomers. Subsequently, they were coated and dried on the surface of polydimethylsiloxane (PDMS) chips with either flat or microgroove surfaces to produce the corresponding collagen-silica hybrid membrane with a flat or microgroove surface. Scanning electron microscopy images showed that membranes formed on flat PDMS chips exhibited smooth and dense surfaces, while those formed on microgrooved PDMS chips exhibited typical microgroove surfaces with a 10 mu m groove width, 8 mu m ridge width, and 0.5 mu m depth. Despite the difference in surface topography, both flat and microgrooved collagen-silica membranes exhibited stronger resistance against collagenase enzyme than the original collagen membrane due to the presence of silica, and the biodegradation rate of the samples was controllable through adjustment of the GPTMS content. Upon incubation with C2C12 skeletal myoblasts, both samples supported cell attachment, proliferation, and differentiation, suggesting good biocompatibility. However, a significant difference in cell morphology was observed. Cells on the flat membranes were randomly distributed, while those on the microgrooved samples were highly aligned and elongated, indicating that the microgrooved membranes exhibit much stronger cell contact guidance ability. The immunochemical assay showed that both flat and microgrooved samples supported the differentiation of C2C12 myoblasts to form multinucleated myotubes; however, the presence of the microgrooved surface topography significantly enhanced cell differentiation.