Calcium Sulfate-Chitosan Cement Interface Study

This study is led by Dr. Liuyun Jiang (National & Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources, Key Laboratory of Light Energy Conversion Materials of Hunan Province College, Hunan Normal University) and Xiang Hu (State Key Laboratory Developmental Biology of Freshwater Fish, School Life Science, Hunan Normal University). Two calcium sulfate hemihydrate powders with different aspect ratios were prepared, and three chitosan addition methods were adopted to investigate the effect on the surface and interface properties of calcium sulfate/chitosan composite bone cement. The results showed that it lacked chemical bond between chitosan and calcium sulfate, and the short rod calcium sulfate displayed better interface adhesion with chitosan owing to its smaller size, so it possessed shorter setting time, better compressive strength and slower degradation than the long rod calcium sulfate, while the biocompatibility had no remarkable difference. Moreover, chitosan solution as liquid phase was a better solidification mode than citric acid, and calcium sulfate/chitosan composite as solid phase was the worst mode because of poor interface compatibility.Conclusively, it was a simple, low-cost and effective preparation process to choose short rod calcium sulfate powder as solid phase and 1 wt% chitosan solution as liquid phase, which could achieve calcium sulfate/chitosan composite bone cement with the best properties, including setting time, compressive strength, degradation rate and biocompatibility, displaying a promising application in bone defect repair.