Fabrication, microstructure, and BMP-2 delivery of novel biodegradable and biocompatible silicate-collagen hybrid fibril sheets

Silicate-collagen hybrid fibril sheets were obtained using 3-glycidoxypropyl trimethoxysilane (GPTMS) as a novel cross-linker for type I collagen fibrils. BMP-2 was introduced in the hybrid sheets to stimulate cell proliferation and differentiation. Scanning electron microscopy images indicated that the resultant sheets were nanofibrous and porous. Transmission electron microscopy images showed that each hybrid fibril maintained a typical periodic unit of 60-70 nm. Compared to fibrils cross-linked by a conventional carbodiimide agent, the present hybrid fibrils were much more resistant against type I collagenase degradation. When soaked in BMP-2 solution, the hybrid sheets easily adsorbed BMP-2 and exhibited sustained release for BMP-2. Osteoblast-like MC3T3-E1 cells were well attached to and proliferated on the hybrid sheets. The proliferation and differentiation of these cells were enhanced to form collagen fibrils due to BMP-2 release.