Cell-collagen-silica composites and methods of making and using the same

Abstract

Soluble, self-assembling collagens derived from tissues are extensively characterized such that one can predict and customize the final collagen-fibril matrix with respect to fibril microstructure (i.e., fibril density, interfibril branching), viscoelasticity and proteolytic degradability. As shown herein these matrices template and direct the deposition of mesoporous silica at the level of individual collagen fibrils. The fibril density, silicic acid concentration, and time of exposure to silicifying solution were varied and the resulting hybrid materials were analyzed by scanning electron microscopy, energy-dispersive x-ray spectroscopy, and rheology. Microstructural properties of the collagen-fibril template are preserved in the silica surface of hybrid materials. Results for three different collagen fibril densities, corresponding to shear storage moduli of 200 Pa, 1000 Pa, and 1600 Pa, indicate that increased fibril density increases the absolute amount of templated silica when all other silica synthesis conditions are kept constant. The mechanical properties of the hybrid material are dominated by the presence of the silica coating rather than the starting collagen matrix stiffness.