PCEC-CaO-SiO_2-P_2O_5杂化材料

采用分子量为1 500的聚乙二醇(PEG)为大分子引发剂,引发ε-己内酯开环聚合,合成了分子量为2 900、3 400、4 700的端羟基的聚己内酯-聚乙二醇-聚己内酯(PCEC)嵌段共聚物,并用异氰酸基丙基三乙氧基硅烷(IPTS)将该共聚物端羟基修饰。红外结果表明,该聚合物在3 440、1 732、1 242、1 106cm-1等处有羟基、酯键、醚键的特征峰,与IPTS反应后在3 350cm-1、1 531cm-1处出现了N—H的伸缩振动峰和(N—H)+(C—N)的弯曲振动峰,证实了PCEC以及端基为三乙氧基硅基的PCEC结构。采用溶胶-凝胶法将该产物与生物玻璃前躯体进行反应,获得PCEC-CaO-SiO2-P2O5有机-无机杂化材料。PCEC-CaO-SiO2-P2O5杂化材料在模拟体液(SBF)中浸泡24h后,表面就开始覆盖钙磷沉淀物。XRD测试结果表明,PCEC-CaO-SiO2-P2O5杂化材料表面覆盖的沉淀物主要成分为羟基磷灰石,表面沉积物随着杂化材料中亲水性成分的增加而增加。力学性能测试表明,随着高分子中PEG含量的增加,PCEC-CaO-SiO2-P2O5有机-无机杂化材料的压缩模量从6.9 MPa上升到65 MPa。细胞毒性表明,PCEC-CaO-SiO2-P2O5杂化材料对细胞没有明显的毒性。

PCEC-CaO-SiO2-P2O5 hybrid materials

The polycaprolactone-polyethylene glycol-polycaprolactone triblock polymer (PCEC) and the PCEC end caped with triethoxysilane were synthesized for the organic-inorganic hybrid materials fabrication. The characteristic absorption bands at 3 440, 1 732, 1 242 and 1 106 cm^-1 assigned to PCEC, as well as absorption bands at 3 350 cm^-1 and 1 531 cm^-1 assigned to the urethane bond of the end caped PCEC were revealed by the FTIR spectra. The hybrid PCEC-CaO-SiO₂-P₂O₅ material was synthesized by the end caped PCEC with tetraethyl orthosilicate, calcium nitrate tetrahydrate and triethyl phosphate via a sol-gel method. The bioactivity of the PCEC-CaO-SiO₂-P₂O₅ hybrid material was assessed using simulated body fluid. SEM pictures display that precipitate with the calcium phosphate was presented on the surface after soaking for 24 h. XRD results show that the diffraction peaks of precipitate have the characteristic of hydroxyapatite. It is also revealed that the polymer hydrophobicity would influence the precipitate formation on the hybrid material surface. The mechanics performance test shows that with the increase of PEG content in the polymer, the compression modulus increases from 6.9 MPa to 65 MPa. The cell viability experiments show that PCEC-CaO-SiO₂-P₂O₅ hybrid material has no significant cytotoxic.