Preparation of a porous chitosan/fibroin-hydroxyapatite composite matrix for tissue engineering

Chitosan, fibroin, and hydroxyapatite are natural biopolymers and bioceramics that are biocompatible, biodegradable, and resorbable for biomedical applications. The highly porous, chitosan-based, bioceramic hybrid composite, chitosan/fibroin-hydroxyapatite composite, was prepared by a novel method using thermally induced phase separation. The composite had a porosity of more than 94% and exhibited two continuous and different morphologies: an irregularly isotropic pore structure on the surface and a regularly anisotropic multilayered structure in the interior. In addition, the composite was composed of an interconnected open pore structure with a pore size below a few hundred microns. The chemical composition, pore morphology, microstructure, fluid absorptivity, protein permeability, and mechanical strength were investigated according to the composition rate of bioceramics to biopolymers for use in tissue engineering. The incorporation of hydroxyapatite improved the fluid absorptivity, protein permeability, and tenacity of the composite while maintaining high porosity and a suitable microstructure.