Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland 4059, Australia.
J Biomed Mater Res A. 2011 Jul;98(1):122-31. doi: 10.1002/jbm.a.33092. Epub 2011 May 4.
Poly(lactide-co-glycolide) (PLGA) microspheres have been used for regenerative medicine due to their ability for drug delivery and generally good biocompatibility, but they lack adequate bioactivity for bone repair application. CaSiO₃ (CS) has been proposed as a new class of material suitable for bone tissue repair due to its excellent bioactivity. In this study, we set out to incorporate CS into PLGA microspheres to investigate how the phase structure (amorphous and crystal) of CS influences the in vitro and in vivo bioactivity of the composite microspheres, with a view to the application for bone regeneration. X-ray diffraction (XRD), N₂ adsorption-desorption analysis, and scanning electron microscopy (SEM) were used to analyze the phase structure, surface area/pore volume, and microstructure of amorphous CS (aCS) and crystal CS (cCS), as well as their composite microspheres. The in vitro bioactivity of aCS and cCS-PLGA microspheres was evaluated by investigating their apatite-mineralization ability in simulated body fluids (SBF) and the viability of human bone mesenchymal stem cells (BMSCs). The in vivo bioactivity was investigated by measuring their de novo bone-formation ability. The results showed that the incorporation of both aCS and cCS enhanced the in vitro and in vivo bioactivity of PLGA microspheres. cCS/PLGA microspheres improved better in vitro BMSC viability and de novo bone-formation ability in vivo, compared to aCS/PLGA microspheres. Our study indicates that controlling the phase structure of CS is a promising method to modulate the bioactivity of polymer microsphere system for potential bone tissue regeneration.
聚（乳酸-共-乙醇酸）（PLGA）微球由于其药物传递能力和良好的生物相容性而被用于再生医学，但它们缺乏足够的生物活性用于骨修复应用。CaSiO₃（CS）由于其优异的生物活性已被提议作为一种适用于骨组织修复的新型材料。在这项研究中，我们将 CS 掺入 PLGA 微球中，以研究 CS 的相结构（非晶态和晶态）如何影响复合微球的体外和体内生物活性，以期应用于骨再生。X 射线衍射（XRD）、N₂吸附-解吸分析和扫描电子显微镜（SEM）用于分析非晶态 CS（aCS）和晶态 CS（cCS）及其复合微球的相结构、比表面积/孔体积和微观结构。通过研究它们在模拟体液（SBF）中的磷灰石矿化能力和人骨髓间充质干细胞（BMSCs）的活力来评估 aCS 和 cCS-PLGA 微球的体外生物活性。通过测量新骨形成能力来研究其体内生物活性。结果表明，掺入 aCS 和 cCS 均增强了 PLGA 微球的体外和体内生物活性。与 aCS/PLGA 微球相比，cCS/PLGA 微球在体外提高了更好的 BMSC 活力和体内新骨形成能力。我们的研究表明，控制 CS 的相结构是调节聚合物微球系统生物活性以用于潜在骨组织再生的一种有前途的方法。
