Objective To extend the application of polymethyl methacrylate (PMMA) in the field of bone repair by adding mineralized collagen(MC) for modification.Methods The different contents and particle sizes of MC/PMMA modified bone cement were prepared by adding different concentrations of MC(5 wt%, 10 wt%, 15 wt%, 20 wt%). Working characteristics, compressive strength test, bending strength test and compression modulus test were obtained. The mechanical properties of modified bone cement were evaluated and the composite cement ratio with the best performance was determined.Results The working characteristics of MC/PMMA was as follows: The mixing time was 30 s, the waiting time was 2-5 min, the working time was 5-12 min, and the curing time was 10-20 min. MC had little effect on the compressive strength of PMMA, and the compressive strength of MC/PMMA can be kept above 70 MPa in a certain range (content: 5 wt%, 10 wt%, 15 wt%, 20 wt%; particle size: <200 μm, 200-300 μm, 300-400 μm, 400-500 μm). The compressive strength, flexural strength and compressive modulus of MC/PMMA (15wt%, 300-400 μm in diameter) were 90 MPa, 50 MPa and 1.2 GPa respectively. The elastic modulus of MC/PMMA was significantly lower than that of Osteopal V and Mendec Spine, and matched with the elastic modulus of human bone.Conclusion While maintaining the mechanical strength of PMMA, MC can reduce its elastic modulus. The working characteristics, compressive and flexural strength and elastic modulus of MC/PMMA bone cement with a content of 15 wt% and a particle size of 300-400 μm meet international standards and clinical application requirements. |