快速成型模板调制双相掺锶磷酸钙陶瓷骨支架的结构与性能

Structure and Properties of Sr-Containing BCP Scaffolds Modulated by RP Porous Negative Mould

以高强可降解掺锶磷灰石骨水泥(Sr-HAC)为原料,以快速成型(RP)宏孔可控树脂为模板,合成了由掺锶磷灰石(Sr-HA)、掺锶磷酸钙(Sr-TCP)组成的新型双相掺锶磷酸钙(Sr-BCP)骨支架。结果表明,Sr-BCP骨支架相组成可根据Sr-HAC的(Ca+Sr)/P比率予以调控。骨支架宏孔高度连通,孔径400～550μm,且宏孔壁上具有丰富的微孔(孔径2～5μm)。此外,骨支架宏孔参数可通过设计不同孔结构的负模予以反向调控。宏孔百分数与相组成对Sr-BCP支架的抗压强度与降解速率有重要影响。与BCP骨支架相比,Sr-BCP骨支架具有更高的强度及更快的降解速率,一定程度上缓解了BCP陶瓷骨支架在力学和降解性能上难以兼顾的矛盾。

A new type of St-containing biphasic calcium phosphate （Sr-BCP） porous scaffolds were in situ synthesized with Sr-containing calcium phosphate cement （Sr-HAC） hardened bodies as starting materials and structure-controllable rapid-prototyping （RP） porous resins as the negative moulds. Results show that the final product is composed of Sr-containing hydroxyapatite （St-HA） and Sr-containing tricalcium phosphate （Sr-TCP）. The phase composition of the product is easily adjusted by the （Ca＋Sr）/P molar ratio of the Sr-HAC. The Sr-BCP porous scaffold possesses high intraconnective macropores （Ф400-550μm） and abundant micropores （2-5μm） distributed in the macropore wall. Both phase composition and macropore percentage of the Sr-BCP scaffold play important roles in their in vitro compressive strengths （CS） and degradation rates. The Sr-BCP scaffold exhibits higher strength and faster degradation rate than the Sr-free one, which to some extent decreases the confliction between mechanical strength and degradation rate of the existing Sr-free BCP bone scaffold.