Preparation Of Polyphosphoester/β-TCP Based Bone Repair Materials And Biomineralization In Vitro

Injectable bone repair materials which could be injected into the injury site and could be cured in situ possess many benifits such as minimal surgical intervention and less complications as well as less pain for the patients. Therefore developing an injectable bone repair materials with biocompatibility is promising for clinical therapy.In this thesis, we developed a polymer-ceramic composite consisting of unsaturated polyphosphoester (UPPE) and calcium phosphate. The property of this composite was also specifically investigated. The paste of the composite before curing had a proper viscosity for injection. Besides, the maximum curing temperature of crosslinking polymerization reaction in situ was between 41.8℃and 68.6℃. The porosity of crosslinked composite could reach higher than 75%, and the compressive strength could be higher than 10 MPa which was nearly that of cancellous bone in human body. What's more, the wet strength of this composite was 0.96±0.07 MPa which could meet the requirement of common filling for the defect site. Particularly, the composite could control the rate of drug release, therefore it could cure the injury site when the bone defect was repaired.The perfomance of biomineralization on this composite in simulated body fluid (SBF) was studied. The UPPE/β-TCP based composite could form biomineralization in vitro and was obviously faster than that ofβ-TCP powder.Finally, we combined PLA and crosslinked UPPE to form CUPPE/PLA scaffolds. As the amount of PLA increased, the degree of phase separation became higher leading to the descent of dry strength, but the time of drug release was extended. Theβ-TCP ceramic could improve the wet strength of CUPPE/PLA scaffolds, and the compressive strength could reach 2.32 ~ 4.54 MPa.