Department of Bioscience and Biotechnology, National Taiwan Ocean University, Taiwan.
Department of Bioscience and Biotechnology, National Taiwan Ocean University, Taiwan.
Mater Sci Eng C Mater Biol Appl. 2018 Aug 1;89:346-354. doi: 10.1016/j.msec.2018.04.027. Epub 2018 Apr 13.
Mesoporous bioactive glass (MBG) has a greater surface area and pore volume than conventional BG. Hence, MBG is useful as a drug delivery carrier. Previously, MBG has been fabricated as dense or porous blocks. Compared to blocks, microbeads have a greater flexibility to fill different-shaped cavities with close packing. Moreover, fibrous materials have proven to increase cell attachment and differentiation because they mimic the three-dimensional structure of the natural extracellular matrix (ECM). Macroporous materials possess porous structures with interconnecting channels that allow the invasive growth of cells and capillaries. Hence, the aim of this study was to fabricate macroporous microbeads containing MBG nanofibres (MMBs). We used poly(methyl methacrylate) (PMMA) microspheres as the macroporous template in the process and removed the PMMA microspheres after the calcination treatment. Scanning electron microscopy imaging showed multiple pores on the surface of the MMBs, and a micro-computed tomography image showed the presence of pores throughout the entire microbead. The cellular attachment of MG63 osteoblast-like cells was considerably higher on the MMBs than on glass beads after culturing for 4 h. However, the cell viability greatly decreased after culturing for 1 day. We speculated that the release of a high concentration of calcium ions from the MMBs decreased the cell viability. To improve the cell viability, we modified the MMBs by immersing the MMBs in a simulated body fluid to fabricate a thin apatite layer on the surface of the MMBs. The apatite-modified MMBs (Ap-MMB) decreased the release of calcium ions and improved the cell viability. In an animal study, the bone defect in the control group did not recover. In contrast to the control group, the Ap-MMBs in the defect were nearly filled with new bone. The results show that the Ap-MMBs have great potential in osteogenesis for bone tissue engineering.
介孔生物活性玻璃（MBG）的比表面积和孔体积大于传统 BG。因此，MBG 可用作药物输送载体。 此前，MBG 已被制成致密或多孔块。与块体相比，微珠具有更大的灵活性，可以用紧密堆积的方式填充不同形状的腔。 此外，纤维材料已被证明可以增加细胞附着和分化，因为它们模拟了天然细胞外基质（ECM）的三维结构。 大孔材料具有具有相互连接的通道的多孔结构，允许细胞和毛细血管侵入生长。因此，本研究的目的是制备含有 MBG 纳米纤维的大孔微珠（MMBs）。我们在该过程中使用聚甲基丙烯酸甲酯（PMMA）微球作为大孔模板，并在煅烧处理后去除 PMMA 微球。扫描电子显微镜成像显示 MMBs 表面有多个孔，微计算机断层扫描图像显示整个微珠中都存在孔。与玻璃珠相比，MG63 成骨样细胞在 MMBs 上的细胞附着率在培养 4 小时后明显更高。然而，培养 1 天后细胞活力大大降低。我们推测 MMBs 中释放出的高浓度钙离子降低了细胞活力。为了提高细胞活力，我们将 MMBs 浸入模拟体液中，在 MMBs 表面制造一层薄的磷灰石层，对 MMBs 进行改性。磷灰石改性 MMBs（Ap-MMBs）减少了钙离子的释放，提高了细胞活力。在动物研究中，对照组的骨缺损没有恢复。与对照组相比，缺陷中的 Ap-MMB 几乎被新骨填充。结果表明，Ap-MMBs 在骨组织工程中的成骨方面具有很大的潜力。
