Välimäki V V, Aro H T
Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology University of Turku, Turku, Finland.
Scand J Surg. 2006;95(2):95-102. doi: 10.1177/145749690609500204.
Bone grafting procedures are undergoing a major shift from autologous and allogeneic bone grafts to synthetic bone graft substitutes. Bioactive glasses are a group of synthetic silica-based bioactive materials with bone bonding properties first discovered by Larry Hench. They have several unique properties compared with other synthetic bioresorbable bioactive ceramics, such as calcium phosphates, hydroxyapatite (HA) and tricalcium phosphate (TCP). Bioactive glasses have different rates of bioactivity and resorption rates depending on their chemical compositions. The critical feature for the rate of bioactivity is a SiO2 content < 60% in weight. In vivo, the material is highly osteoconductive and it seems to promote the growth of new bone on its surface. In a recent study, the activity of the material was found even to overshadow the effect of BMP-2 gene therapy. In vivo, there is a dynamic balance between intramedullary bone formation and bioactive glass resorption. Recent studies of molecular biology have shown that bioactive glass induces a high local turnover of bone formation and resorption. Many osteoporotic fracture patients are candidates for concurrent treatment with bisphosphonates and bioceramic bone graft substitutes. Since osteopromotive silica-based bioactive glasses induce accelerated local bone turnover, adjunct antiresorptive agents may affect the process. However, a recent study showed that an adjunct antiresorptive therapy (zoledronic acid) is even beneficial for bone incorporation of bioactive glass. Based on these observations, bioactive glasses are a promising group of unique biomaterials to act as bone graft substitutes.
骨移植手术正在经历从自体骨和异体骨移植向合成骨移植替代物的重大转变。生物活性玻璃是一类基于二氧化硅的合成生物活性材料，具有骨结合特性，最初由拉里·亨奇发现。与其他合成可生物吸收的生物活性陶瓷，如磷酸钙、羟基磷灰石（HA）和磷酸三钙（TCP）相比，它们具有几个独特的特性。生物活性玻璃根据其化学成分具有不同的生物活性速率和吸收率。生物活性速率的关键特征是二氧化硅含量重量比<60%。在体内，该材料具有高度的骨传导性，似乎能促进其表面新骨的生长。在最近的一项研究中，发现该材料的活性甚至超过了BMP - 2基因治疗的效果。在体内，骨髓内骨形成与生物活性玻璃吸收之间存在动态平衡。分子生物学的最新研究表明，生物活性玻璃能诱导骨形成和吸收的局部高周转率。许多骨质疏松性骨折患者适合同时使用双膦酸盐和生物陶瓷骨移植替代物进行治疗。由于具有促骨生成作用的基于二氧化硅的生物活性玻璃会加速局部骨转换，辅助抗吸收剂可能会影响这一过程。然而，最近的一项研究表明，辅助抗吸收疗法（唑来膦酸）甚至有利于生物活性玻璃的骨结合。基于这些观察结果，生物活性玻璃是一类很有前景的独特生物材料，可作为骨移植替代物。
