Polypeptide graft copolymers such as poly(γ-benzyl-L-glutamate)(PBLG)-poly(ethylene glycol)(PEG) and poly(γ-ethyl-L-glutamate)(PELG)-poly(ethylene glycol)(PEG) were introduced into self-setting calcium phosphate cement(CPC) system to improve its mechanical properties. The compression strength was improved considerably by the induction of polypeptide copolymers. It is about 22.3 higher for PBLG-g-PEG and 65.0 higher for PELG-g-PEG, respectively. The results also show that for the same polypeptide copolymer, higher compression strength of composites can be obtained by introducing copolymer micelles into the CPC. According to the results of scanning electron microscope(SEM), the crystallite shapes of CPC depend on the weight fraction of polypeptide copolymer in the composites.
