The Research On The Preparation Method And Degradation Behavior Of UPPE/?-TCP As An Injectable Bone Repair Material

As one of the two chief stomatology diseases, periodontal disease is of high prevalence rate all over the world. And with the aging of the population and the promotion of people's health consciousness, alveolar bone defect, which is induced by periodontal disease, has become a serious issue that influence the patients' health and even their normal life. Thus, to develop a new kind of bone-repair scaffold material with simple surgical operation, low tissue damage and controllable degradation behavior is quite essential. Polyphosphoester is a biomaterial with favorable biocompatibility and biodegradability with its backbone degradable through hydrolyzation or enzymatic decomposition in physiological environment. But its strength is relatively low as scaffold material. ?-triealeiumphosphate(?-TCP) is of good biocompatibility and osteoconduction, while it is of high osteoconduction and is hard to mold. In this thesis, a kind of unsaturated polyphosphoester(UPPE) with unsaturated double bones in the backbone is synthesized. And UPPE/?-TCP composite which is injectable and can cure in-situ is prepared to treat the defect of alveolar bone. Besides, the in-vitro degradation behavior of the composite is systematically studied.UPPE is synthesized by the polycondensation reaction between bis(1,2-propylene glycol) fumarate(BPGF) and ethyl dichlorophosphate(EDP) using solution polymerization. NMR spectra indicates that there exist three bonding models on the backbone. The results of GPC shows that the molecular weight and molecular weight distribution of the UPPE reacted for 16 h are respectively 3050 g/mol and 1.39. And the DSC curve of UPPE indicate that the glass-transition temperature of UPPE is-31.5 ?.The UPPE/?-TCP composite can be crosslinked using dibenzoyl peroxide(BPO) /N, N-dimethyl methyl aniline(DMT) as initiators and N-vinypyrrolidone(NVP) as the crosslinker. The viscosity of the composite can be justified by changing the content of ?-TCP and NVP to guarantee the injectability. The results show that the viscosity range of the composite is 0.5-15.7Pa?s. The content of ?-TCP, NVP and BPO affects the setting time and the maximum setting temperature of the composite. The setting time is between 3.2 s to 9.8 s, and the maximum setting temperature is between 38.5 to 45.8 ?.The degradation of the composite can be divided into two stages. In the first 3 days of degradation, NVP and PVP dissolve into the simulated body fluid(SBF) rapidly, and simultaneously the rapid mass loss, length and diameter increase and mechanical property decrease occur. After the first 3 days, the weight loss is mainly attributed to the degradation of the crosslinked material and the speed becomes much slower. The content of ?-TCP, NVP and Na Cl can obviously affect the mass loss, dimension change, strength change, and the p H change of the SBF during the degradation process. The XRD spectra and SEM images of the composite material after degradation shows that hydroxyapatite occurs on the surface, which indicates that this material is of good biocompatibility.