Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy.
INSTM, National Interuniversity Consortium of Materials Science and Technology, Local Unit Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy.
J Mater Sci Mater Med. 2020 Feb 14;31(3):26. doi: 10.1007/s10856-020-6363-2.
The regeneration of injured or damaged tissues by cell delivery approaches requires the fabrication of cell carriers (e.g., microspheres, MS) that allow for cell delivery to limit cells spreading from the injection site. Ideal MS for cell delivery should allow for cells adhesion and proliferation on the MS before the injection, while they should allow for viable cells release after the injection to promote the damaged tissue regeneration. We optimized a water-in-oil emulsion method to obtain gelatin MS crosslinked by methylenebisacrylamide (MBA). The method we propose allowed obtaining spherical, chemically crosslinked MS characterized by a percentage crosslinking degree of 74.5 ± 2.1%. The chemically crosslinked gelatin MS are characterized by a diameter of 70.9 ± 17.2 μm in the dry state and, at swelling plateau in culture medium at 37 °C, by a diameter of 169.3 ± 41.3 μm. The MS show dimensional stability up to 28 days, after which they undergo complete degradation. Moreover, during their degradation, MS release gelatin that can improve the engraftment of cells in the injured site. The produced MS did not induce any cytotoxic effect in vitro and they supported viable L929 fibroblasts adhesion and proliferation. The MS released viable cells able to colonize and proliferate on the tissue culture plastic, used as release substrate, potentially proving their ability in supporting a simplified in vitro wound healing process, thus representing an optimal tool for cell delivery applications.
细胞递送方法通过细胞载体（例如微球，MS）的制造来实现受损或损坏组织的再生，这些细胞载体允许细胞递送到限制细胞从注射部位扩散的程度。用于细胞递送的理想 MS 应允许细胞在注射前在 MS 上黏附和增殖，同时应允许在注射后释放活细胞以促进受损组织再生。我们优化了水包油乳液法，以获得通过亚甲基双丙烯酰胺（MBA）交联的明胶 MS。我们提出的方法允许获得球形的化学交联 MS，其交联度为 74.5±2.1%。化学交联的明胶 MS 在干燥状态下的直径为 70.9±17.2μm，在 37°C 下在培养基中达到溶胀平台时，直径为 169.3±41.3μm。MS 可保持尺寸稳定性长达 28 天，之后会完全降解。此外，在降解过程中，MS 释放明胶，可改善细胞在受损部位的植入。体外实验表明，所制备的 MS 不会引起任何细胞毒性作用，并且可以支持 L929 成纤维细胞的黏附和增殖。MS 释放的活细胞能够在用作释放基底的组织培养塑料上定植和增殖，这可能证明它们在支持简化的体外伤口愈合过程方面的能力，因此代表细胞递送应用的理想工具。
