Biodegradation behavior of chitosan/calcium phosphate composites

A variety of biomimetic materials with structural and mechanical equivalence to bone have been developed to repair bone defects. Chitosan/calcium phosphate composites composed of bioactive calcium phosphate and flexible chitosan were made by a simple mixing-and-heating method. Mechanical properties, morphology, phase composition, and weight change after immersion in Hanks' solution were evaluated. Experimental results showed that the formation of pores/cracks on immersed sample surface obviously depended on the calcium phosphate content and immersion time. The immersion time imposed in this study did have a statistically significant effect on mechanical properties. When immersed for 90 days in Hanks' solution, the strength of immersed composites containing 10 wt/v% calcium phosphate with the initial strength of 27 MPa was about 2 MPa, having a reduction of 92%. Based on the above results, the organic-inorganic hybrid composites with high initial strength might be an acceptable material candidate for bone tissue repair. (C) 2007 Elsevier B.V. All rights reserved.