Ravarian R, Wei H, Dehghani F
University of Sydney, School of Chemical and Biomolecularengineering, Sydney, Australia.
Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:3593-6. doi: 10.1109/IEMBS.2011.6090601.
Binary system of CaO-SiO(2) glasses enables the apatite formation in simulated body fluid (SBF). However, the presence of phosphate content in SiO(2)-CaO-P(2)O(5) glasses leads to the formation of orthophosphate nanocrystalline nuclei, which facilitates the generation of carbonate hydroxyapatite; this compound is more compatible with natural bone. The brittle and less flexible properties of bioactive glasses are the major obstacle for their application as bone implant. The hybridization of essential constituents of bioactive glasses and glass-ceramics with polymers such as PMMA can improve their poor mechanical properties. The aim of this study was to improve the bioactivity of nanocomposites fabricated from poly(methyl metacrylate) (PMMA) and bioglass for bone implant applications. Bioglass compounds with various phosphate contents were used for the preparation of PMMA/bioglass hybrid matrices. Since the lack of adhesion between the two phases impedes the homogenous composite formation, a silane coupling agent such as 3-(trimethoxysilyl)propyl methacrylates (MPMA) was incorporated into the polymer structure. The effect of addition of MPMA on the molecular structure of composite was investigated. Furthermore, the presence of MPMA in the system improved the homogeneity of sample. Increasing phosphate content in the inorganic segment of hybrid up to 10 mol% resulted in the formation of apatite layer on the surface; hence the hybrid was bioactive and suitable candidate for bone tissue engineering.
CaO-SiO₂玻璃二元体系能够在模拟体液(SBF)中形成磷灰石。然而,SiO₂-CaO-P₂O₅玻璃中磷酸盐成分的存在会导致正磷酸盐纳米晶核的形成,这有利于生成碳酸羟基磷灰石;这种化合物与天然骨更具相容性。生物活性玻璃的脆性和柔韧性较差是其作为骨植入物应用的主要障碍。将生物活性玻璃和玻璃陶瓷的基本成分与聚合物(如聚甲基丙烯酸甲酯,PMMA)进行杂化,可以改善其较差的机械性能。本研究的目的是提高由聚甲基丙烯酸甲酯(PMMA)和生物玻璃制备的用于骨植入应用的纳米复合材料的生物活性。使用具有不同磷酸盐含量的生物玻璃化合物制备PMMA/生物玻璃混合基质。由于两相之间缺乏附着力会阻碍均匀复合材料的形成,因此将硅烷偶联剂(如3-(三甲氧基甲硅烷基)丙基甲基丙烯酸酯,MPMA)引入聚合物结构中。研究了添加MPMA对复合材料分子结构的影响。此外,体系中MPMA的存在改善了样品的均匀性。将混合材料无机部分中的磷酸盐含量增加至10 mol%会导致在表面形成磷灰石层;因此,该混合材料具有生物活性,是骨组织工程的合适候选材料。