Chen Qizhi Z, Thompson Ian D, Boccaccini Aldo R
Department of Materials and Centre for Tissue Engineering and Regenerative Medicine, Imperial College London, Prince Consort Road, London SW7 2BP, UK.
Biomaterials. 2006 Apr;27(11):2414-25. doi: 10.1016/j.biomaterials.2005.11.025. Epub 2005 Dec 5.
Three-dimensional (3D), highly porous, mechanically competent, bioactive and biodegradable scaffolds have been fabricated for the first time by the replication technique using 45S5 Bioglass powder. Under an optimum sintering condition (1000 degrees C/1h), nearly full densification of the foam struts occurred and fine crystals of Na2Ca2Si3O9 formed, which conferred the scaffolds the highest possible compressive and flexural strength for this foam structure. Important findings are that the mechanically strong crystalline phase Na2Ca2Si3O9 can transform into an amorphous calcium phosphate phase after immersion in simulated body fluid for 28 days, and that the transformation kinetics can be tailored through controlling the crystallinity of the sintered 45S5 Bioglass. Therefore, the goal of an ideal scaffold that provides good mechanical support temporarily while maintaining bioactivity, and that can biodegrade at later stages at a tailorable rate is achievable with the developed Bioglass-based scaffolds.
首次使用45S5生物玻璃粉末通过复制技术制备了三维（3D）、高度多孔、具有机械性能、生物活性和可生物降解的支架。在最佳烧结条件（1000℃/1小时）下，泡沫支柱几乎完全致密化，并形成了Na2Ca2Si3O9细晶，这赋予了该支架对于这种泡沫结构而言尽可能高的抗压强度和抗弯强度。重要的发现是，机械强度高的晶相Na2Ca2Si3O9在模拟体液中浸泡28天后可转变为无定形磷酸钙相，并且可以通过控制烧结的45S5生物玻璃的结晶度来调整转变动力学。因此，利用所开发的基于生物玻璃的支架，实现提供临时良好机械支撑同时保持生物活性，并能在后期以可调整速率生物降解的理想支架的目标是可以实现的。
