摘要
生物活性玻璃是一种生物活性材料,具有骨传导和骨诱导活性,在移植后可与宿主骨产生紧密结合并促进成骨。根据材料组成可分为硅酸盐生物活性玻璃、磷酸盐生物活性玻璃和硼酸盐生物活性玻璃等。目前硅酸盐生物活性玻璃最常见,而磷酸盐和硼酸盐生物活性玻璃具有较高的溶出降解速率。熔融法和溶胶-凝胶法是最基础的两种制造工艺,分别可制得熔融法生物活性玻璃和溶胶-凝胶生物活性玻璃,后者所需热处理温度低,具有较高的比表面积和更好的生物活性。经热处理可获得生物活性微晶玻璃,提升了力学强度但生物活性稍降低;经其他处理方式改变材料的结构尺寸可获得比表面积更高的纳米生物活性玻璃。在此基础上可制成3D支架,或与其他生物材料复合制成复合生物活性玻璃支架,获得具有分级或仿生结构的三维互通孔隙,以提升力学强度,增强其成骨活性并提供适宜宿主骨的机械支撑。但生物活性玻璃的生物活性在一定程度上依赖于降解速率,与机械强度间存在一定矛盾,可通过选择合适的孔隙率或可控的降解速率,满足早期支撑和成骨的共同需求。在基础研究方面,有研究证实生物活性玻璃溶出离子通过巨胞饮途径作用于细胞,上调相关基因表达促进成骨;生物活性玻璃的降解速率与结构和组成相关,可对生物活性玻璃降解过程中的力学强度变化进行定量预测;在结构力学及检验方法方面也有所进展。
Bioactive glasses (BGs) are a kind of biomaterials with osteoconductive and osteoinductive properties and are able to create a strong bond with host bone and promote osteogenesis after implantation. According to their compositions, bioactive glasses can be classified as silicate BGs, phosphate BGs, and borate BGs. Nowadays, silicate BGs are still the most common, while phosphate BGs and borate BGs have higher dissolution and degradation rates. Melt-quenching and sol-gel process are two basic methods to produce melt-derived BGs and sol-gel BGs, respectively. The latter requires lower heat treatment temperature with higher specific surface area and biological activity. Bioactive glass-ceramics can be obtained by heat treatment, which improves the mechanical strength but slightly reduces the bioactivity. Nano-bioactive glasses with the higher specific surface area can be obtained by changing the structure size of the materials by other treatment methods. On this basis, 3D BGs scaffolds can be made, and hybrid BGs scaffolds as well by combining with other biomaterials to obtain the 3D interconnected pores with the hierarchical or bionic structures, to enhance the mechanical strength, osteogenic activity and provide mechanical support suitable for the host bone. However, the bioactivity of BGs depends on the degradation rate, to some extent, which is contradictory to the mechanical strength. An appropriate porosity or controllable degradation rate can be selected to meet the common needs of early support and osteogenesis. In basic studies, it was found that BGs could act on cells by releasing ions or through the macropinocytosis pathway, up-regulating the expression of related genes or promoting osteogenesis. The degradation rates of BGs are related to their structures and compositions, which enables the quantitative prediction of the change of mechanical strength during degradation. Progress has also been made in structural mechanics and testing methods.
作者
许明悠
刘永恒
汪鹏生
胡永成
Xu Mingyou;Liu Yongheng;Wang Pengsheng;Hu Yongcheng(Department of Orthopedic Oncology, Tianjin Hospital, Tianjin 300211, China;The Graduate School, Tianjin Medical University, Tianjin 300070, China;Weidafeng Medical Biological Material Co., Ltd, Beijing 100176, China)
出处
《中华骨科杂志》
CAS
CSCD
北大核心
2019年第7期440-448,共9页
Chinese Journal of Orthopaedics
