创干细胞疗法是一种有效的治疗损伤和疾病的方法。尽管有巨大潜力，但注射后的细胞存活与扩散存在困难，植入率低，临床转化困难。生物医学水凝胶作为精细加工方向有巨大潜力，其三维结构有助于细胞存活。本文作者提出一种微流控技术搭载骨髓间充质干细胞和生长因子的光交联明胶微球用于可注射，促进骨组织成长。作者还证明了微球可以维持干细胞的活性，支持细胞的扩散和迁移，并促进细胞增殖。此外，干细胞保持高度分化能力，在体内体外有明显的增强成骨作用，矿化效果显著增加。总之，作者提出的新策略可以最小的入侵性促进骨再生，可以与其他模块一起用于扩展应用。

Direct injection is a minimally invasive method of stem cell transplantation for numerous injuries and diseases. However, despite its promising potential, its clinical translation is difficult due to the low cell retention and engraftment after injection. With high versatility, high-resolution control and injectability, microfabrication of stem-cell laden biomedical hydrogels holds great potential as minimally invasive technology. Herein, a strategy of microfluidicsassisted technology entrapping bone marrow-derived mesenchymal stem cells (BMSCs) and growth factors in photocrosslinkable gelatin (GelMA) microspheres to ultimately generate injectable osteogenic tissue constructs is presented. Additionally, it is demonstrated that the GelMA microspheres can sustain stem cell viability, support cell spreading inside the microspheres and migration from the interior to the surface as well as enhance cell proliferation. This finding shows that encapsulated cells have the potential to directly and actively participate in the regeneration process. Furthermore, it is found that BMSCs encapsulated in GelMA microspheres show enhanced osteogenesis in vitro and in vivo, associated with a significant increase in mineralization. In short, the proposed strategy can be utilized to facilitate bone regeneration with minimum invasiveness, and can potentially be applied along with other matrices for extended applications.

DOI: 10.1002/adfm.201504943

李建超