In situ biomimetic formation of nano-hydroxyapatite crystals on chitosan microspheres

Abstract

Chitosan (CS) is a biocompatible, noncytotoxic biomaterial used before as base material for composites. On the other hand, nano-hydroxyapatite (nHA) is one of the main components of human bones, highly used for biomedical applications. In this work, CS microspheres were produced under a W/O emulsion system. CS microspheres with calcium ions were then exposed to Na3PO4 solution. In situ biomimetic nHA crystals were formed on CS microspheres to generate 15.14 ± 3.15-μm composite microspheres. The microspheres were subsequently seeded with MG63 osteoblasts to observe their cell responses. All microspheres were characterized via scanning electron microscopy (SEM), phase-contrast photomicroscopy, and X-ray diffraction (XRD) analysis. The results showed flake-like shape and islet-like growth of nHA depositions presented on the surface of the CS microspheres. In vitro tests indicated that the CS/nHA microparticles were not only biocompatible but also enhanced cell adhesion and elongation due to the in situ biomimetic synthesis method.