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Characterization of Bio-composite Apatite/Chitosan Cement and its Antibacterial Activity

In this work, we report the physico-chemical properties and antibacterial activity of apatite/chitosan composite cements. The biocomposite was prepared by reaction between dihydrated dicalcium phosphate and calcium hydroxide in the presence of chitosan. The characterization of cement was carried out by Infrared Spectroscopy, X-ray diffraction, Transmission Electron Microscopy and X-ray Scanner with computational image processing. The results show that the setting of the paste is due to the formation of a hydrated tri-calcium phosphate that evolves into a hard calcium-apatite. In the presence of chitosan, the fastness of setting time is attributed to the precipitation of chitosan that strengthens the cohesion between grains. The formed complex evolves into hard Apatite-chitosan composite. In an induced bone defect, the hard composite shows radiopaque homogenous microstructure and intimate contact bone/implant. The antibacterial tests of hard cements show a significant reduction in Staphylococci bacterial growth on the surface of composite grains. This reduction is highly dependent on the type of bacteria, and the percentage of the added antibacterial agent. Bio-composite cement shows total inhibition of Staphylococci aureus and low resistance to Staphylococci epidermidis. The apatite/chitosan composite prepared by the way of cements can have interesting applications as bone substitute material.