Preparation and Characterization of Porous Chitosan-Organically Modified Montmorillonite-Hydroxyapatite(CS-OM-HA) Composites for Biomedical Applications

Abstract

In this study, a porous chitosan (CS)-organically modified montmorillonite (OM)-hydroxyapatite (HA) composite was developed by combining microwave irradiation and gas foaming method. The prepared composite was characterized using X-ray diffraction (XRD), attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy, and scanning electron microscopy (SEM). The synergistic effect of OM and HA on the mechanical and in vitro biological properties (swelling, degradation and protein adsorption) of the composite were evaluated. In addition, the in vitro bioactivity of the composites was studied in simulated body fluid (SBF) for 21 days. The XRD results revealed the formation of an exfoliated structure upon incorporation of OM. ATR-FTIR studies indicated strong molecular interaction among the three different components of the composite. The CS-OM-HA composites exhibited a reduction in swelling, degradation and protein adsorption; whereas an enhancement in bioactivity was witnessed as evidenced by SEM analysis. Furthermore, the CS-OM-HA composites showed a significant enhancement in mechanical (tensile) property in comparison with pure chitosan (CS) and CS-OM composites. An in vitro cytotoxic assay was also performed to determine the biocompatibility of the prepared CS based composites. The results showed that the prepared CS based composites were non-toxic. From the study, it can be concluded that the novel CS-OM-HA composite with improved in vitro biological and mechanical properties has wide potential in non-load bearing orthopedic applications.