Methods: First the alpha-TCP particle and the CPC based on alpha-TCP was synthesized. Then the degummed silk is used to improve the strength and fracture resistance of materials. In vitro experiments, The BMSCs cells were designed and carried out to evaluate the biological reaction of the CPC.
Results: alpha-TCP was synthesized by the reaction between phosphoric acid and CaCO3 slurry. The assist agents of CPC are CaCO3 and DCPD. The mixture powders were mixed with 0.25M 0.25MNaH2PO4/Na2H PO4. The initial setting time is about 7 min, the final setting time is about 17min. The compressive strength reached 7.46MPa and the bending strength reached 5.16MPa. Trypsin was picked out as degumming reagent for the ability of preserving the mechanic integrity of silk. The examination of degummed silk suggested that the sericin can be totally removed under our degumming protocols. The simple twisting method was adopted by us for the sake of adding the degummed silk in 3mm length. The CPC added with degummed silk can reach 12.54MPa of compressive strength and 8.882MPa of bending strength. The setting time is almost the same between the CPC group and the CPC added with degummed silk. Cell attachment, spreading, cell proliferation and differentiation were evaluated and there is no statistic difference between CPC and control group.
Conclusions: With the limitation of these findings, alpha-TCP with the assist agents of CaCO3 and DCPD can almost meet the clinic demands. The compressive and bending stress were improved with the adding degummed silk fiber to CPC.