Biomimetic composite scaffold of hydroxyapatite/gelatin-chitosan core-shell nanofibers for bone tissue engineering.

Good biocompatibility and osteogenesis of three-dimensional porous scaffolds are critical for bone tissue engineering. In this work, biomimetic hydroxyapatite/gelatin-chitosan core-shell nanofibers composite scaffolds have been fabricated to mimic both the specific structure and the chemical composition of natural bone. The coaxial electrospinning technique was introduced to prepare gelatin-chitosan core-shell structured nanofibers mat which formed three-dimensional porous structure for promoting cells growth. The gelatin-chitosan core-shell nanofibers formed Arginine-Glycine-Aspartic acid (RGD)-like structure to mimic the organic component of natural bone extracellular matrix. Hydroxyapatite (Ca10(PO4)6(OH)2, HAP), as the major mineral constituent of native bone, was then deposited onto the surface of gelatin-chitosan core-shell structured nanofibers by a wet chemical method. Compared with chitosan nanofibers, gelatin nanofibers and chitosan-gelatin composite nanofibers, gelatin-chitosan core-shell structured nanofibers improved the mineralization efficiency of hydroxyapatite and formed a homogeneous HAP deposit. When Human osteoblast like cell line (MG-63) were cultured on the materials, the results showed that hydroxyapatite deposited on the gelatin-chitosan core-shell structured nanofibers could further enhance osteoblast cell proliferation. The biomimetic composite scaffolds could be suggested as a promising material to promote osteoblast cell growth in bone tissue engineering.