Abstract: To imporve the biodegradability of self-setting calcium phosphate bone cement (CPC) adding chitosan fibers (CF) is proposed. The degradability of CF/CPC composite artificial bone is reasearched on the basis of single biomaterial equal-degradation- rate hypothesis and the canine condyle defect repairing experiment. Theoretical analysis finds that the existence of fiber makes the degradation function of CF/CPC artificial bone quadratic rather than linear, and the degradation ratio can be controlled by changing CF content in composite artificial bone. In vivo experiment shows that the remainder law of artificial bone is one of high-order functions, similar to the ideal remainder curve for bone tissue engineering scaffold. Higher degradation rate of CF than CPC leads to the formation of macroporous structure inside the CF/CPC artificial bone, which further promotes new bone growth and bone reconstruction, and by regulating the CF content, the degradation rate of CF/CPC artificial bone can well match the bone regeneration.

Key words: Artificial bone, Calcium phosphate bone cement, Chitosan fiber, Composite, Degradation, Constitutive relation, Polymer, Thermal effects, Yield stress