Structural and degradation characteristics of an innovative porous PLGA/TCP scaffold incorporated with bioactive molecular icaritin
Structural and degradation characteristics of an innovative porous PLGA/TCP scaffold incorporated with bioactive molecular icaritin
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DOI：
10.1088/1748-6041/5/5/054109
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发表时间：
2010-10-01
影响因子：
4
通讯作者：
Qin, Ling
中科院分区：
文献类型：
--
作者：
Xie, Xin-Hui;Wang, Xin-Luan;Qin, Ling
植物分子可以化学结合到医用支架材料上。本研究将外源性植物雌激素分子淫羊藿苷与骨传导材料L-丙交酯-乙交酯共聚物/磷酸三钙复合，形成具有缓释功能的聚乳酸-丙交酯/淫羊藿素复合支架材料。因此，本研究考察了三种不同剂量(每100gPLGA/TCP74 mg、7.4 mg和0.74 mg，即PLGA/Tcp/icaritin-H、-M和-L组)对淫羊藿苷的体外降解特性和释药规律。在计算机控制的印刷机上制备了PLGA/TCP/淫羊藿苷复合多孔支架。将PLGA/TCP/ICA支架在37℃的生理盐水中孵育12周，并以纯PLGA/TCP支架为对照。在12周的体外降解过程中，4组支架都发生了变化，包括复合支架的重量、体积和孔径减小，而降解介质中的酸性降低，钙和乳酸浓度增加，尤其是在7周后。降解速率与支架中淫羊藿苷含量的关系得到了解释。支架中淫羊藿苷含量越高，12周内降解越慢。12周后，扫描电子显微镜显示PLGA/Tcp和PLGa/Tcp/Ig-Caritin-L组的表面相对光滑，微孔的数量和大小逐渐减少，而PLGa/Tcp/icaritin-M和PLGa/Tcp/Ig-H组的表面部分保持了多孔形态，并伴随着表面磷和钙含量的下降。PLGA/TCP/淫羊藿苷支架降解后力学性能有所下降，但其多孔结构保持不变，对细胞在体内的迁移和新生组织的植入是必不可少的。12周后，复合支架中淫羊藿苷的控释量达到降解介质中淫羊藿苷含量的70%左右。以上结果表明，PLGA/TCP/淫羊藿苷复合多孔支架的结构和降解性能与淫羊藿苷浓度有关。本研究开发的这种新型复合多孔支架材料可以作为一种良好的支架材料来促进骨修复，特别是在高浓度淫羊藿苷的情况下。然而，需要活体证实才能证实我们的体外研究结果。
Phytomolecules may chemically bind to scaffold materials for medical applications. The present study used an osteoconductive porous poly(L-lactide-co-glycolide)/tricalcium phosphate (PLGA/TCP) to incorporate an exogenous phytoestrogenic molecule icaritin to form a PLGA/TCP/icaritin composite scaffold material with potential slow release of icaritin during scaffold degradation. Accordingly, the present study was designed to investigate its in vitro degradation characteristics and the release pattern of icaritin at three different doses (74 mg, 7.4 mg and 0.74 mg per 100 g PLGA/TCP, i.e. in the PLGA/TCP/icaritin-H, -M and -L groups, respectively). A PLGA/TCP/icaritin porous composite scaffold was fabricated using a computer-controlled printing machine. The PLGA/TCP/icaritin scaffolds were incubated in saline at 37 degrees C for 12 weeks and the pure PLGA/TCP scaffold served as a control. During the 12 weeks in vitro degradation, the scaffolds in all four groups showed changes, including a decrease in weight, volume and pore size of the composite scaffold, while there was a decrease in acidity and an increase in Ca and lactic acid concentrations in the degradation medium, especially after 7 weeks. The rate of degradation was explained by the relationship with the content of icaritin incorporated into the scaffolds. The higher the icaritin content in the scaffolds, the slower the degradation could be observed during 12 weeks. After 12 weeks, the SEM showed that the surface of the PLGA/TCP and PLGA/TCP/icaritin-L groups was relatively smooth with a gradual decrease in number and size of the micropores, while the porous morphology on the surface of the PLGA/TCP/icaritin-M and PLGA/TCP/icaritin-H groups was partly maintained, accompanied by a decrease in phosphate (P) and calcium (Ca) contents at the surface. Though the mechanical property of the PLGA/TCP/icaritin scaffold decreased after degradation, its porous structure was maintained, which was essential for cell migration and ingrowth of newly regenerated tissues in vivo. The controlled release of icaritin from the composite scaffold reached about 70% of the incorporated icaritin into the degradation medium after 12 weeks. The above findings suggested that the structural and degradation properties of the porous composite PLGA/TCP/icaritin scaffold were dependent on icaritin concentrations. This innovative composite porous scaffold material developed in the present study may be used as a good scaffold material for enhancing bone repair, especially at high concentrations of icaritin. In vivo confirmation is, however, needed to substantiate our in vitro findings.