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

Abstract

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.

Keywords: Biomimetic; Bone tissue engineering; Chitosan; Core-shell nanofibers; Gelatin; Hydroxyapatite.