Bioactive properties of chitin/chitosan-calcium phosphate composite materials

Calcium phosphate coating over phosphorylated derivatives of chitin/chitosan material was produced by a process based on phosphorylation, Ca(OH)(2) treatment and SBF (simulated body fluid solution) immersion. Chitin/chitosan phosphorylated using urea and H3PO4 and then soaked in saturated Ca(OH)(2) solution at ambient temperature, which lead to the formation of thin coatings formed by partial hydrolysis of the PO4 functionalities, were found to stimulate the growth of a calcium phosphate coating on their surfaces after soaking in 1.5 x SBF solution for as little as one day. The Ca(OH)(2) treatment facilitates the formation of a calcium phosphate precursor over the phosphorylated chitin/chitosan, which in turn encourages the growth of a calcium deficient apatite coating over the surface upon immersion in SBF solution. The bio-compatibility of calcium phosphate compound-chitin/chitosan composite materials was evaluated by cell culture test using L-929 cells. The initial anchoring ratio and the adhesive strength of L-929 cells for composites was higher than that for the polystyrene disk (LUX, control). The results of in-vitro evaluation suggested that the calcium phosphate-chitin/chitosan composite materials were suitable for cell carrier materials.