Fabrication of porous chitosan/hydroxyapatite nanocomposites: their mechanical and biological properties.

We fabricated novel chitosan/hydroxyapatite (HAp) nanocomposites with porous structure by the co-precipitation and porogen leaching method. SEM observation confirmed that the porous chitosan/HAp nanocomposites with 60.6% and 87.1% porosity showed the interconnective pores with pore diameters in the range of 100-200 mum. The composites were found to be mechanically flexible and could be easily formed into any desired shape. The mechanical strength was enhanced by the heat treatment with saturated steam, which was ascribed to the formation of hydrogen bonds between chitosan molecules. The composites subcutaneously implanted in the backs of SD rats for 3 weeks caused little inflammation, and new blood vessel growth and giant cells were found around the composite accompanied with roughening of the surface due to degradation, showing good biocompatibility and biodegradation.