In-situ generation of chitosan/hydroxyapatite composite microspheres for biomedical application

Chitosan/hydroxyapatite (HA) composite microspheres were firstly fabricated in a water-in-oil (W/O) emulsion by in situ generation of the HA nanoparticles in the chitosan matrix. The inorganic component in the composite microspheres was identified as poorly crystalline nano-HA containing carbonate ions, similar to biological apatite. The SEM and TEM studies indicated that the nano-HA particles were uniformly distributed in the chitosan matrix, and the resulting composite microspheres displayed a good dispersity and an average particle size of about 10 pm. The as-obtained chitosan/HA composite microspheres with uniform microstructures may have more potential for both bone tissue regeneration and drug delivery applications, when compared to those prepared by the traditional mixing method. (C) 2012 Elsevier B.V. All rights reserved.