Institute of Biomaterial Science and Berlin-Brandenburg Centre for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany.
University of Potsdam, Potsdam, Germany.
Clin Hemorheol Microcirc. 2020;74(1):53-66. doi: 10.3233/CH-199235.
Microfibers with a core-shell structure can be produced by co-axial electrospinning, allowing for the functionalization of the outer layer with bioactive molecules. In this study, a thermoplastic, degradable polyesteretherurethane (PEEU), consisting of poly(p-dioxanone) (PPDO) and poly(ɛ-caprolactone) (PCL) segments with different PPDO to PCL weight ratios, were processed into fiber meshes by co-axial electrospinning with gelatin. The prepared PEEU fibers have a diameter of 1.3±0.5 μm and an elastic modulus of around 5.1±1.0 MPa as measured by tensile testing in a dry state at 37°C, while the PEEU/Gelatin core-shell fibers with a gelatin content of 12±6 wt% and a diameter of 1.5±0.5 μm possess an elastic modulus of 15.0±1.1 MPa in a dry state at 37 °C but as low as 0.7±0.7 MPa when hydrated at 37 °C. Co-axial electrospinning allowed for the homogeneous distribution of the gelatin shell along the whole microfiber. Gelatin with conjugated Fluorescein (FITC) remained stable on the PEEU fibers after 7 days incubation in Phosphate-buffered saline (PBS) at 37 °C. The gelatin coating on PEEU fibers lead to enhanced human adipose tissue derived mesenchymal stem cell (hADSC) attachment and a proliferation rate 81.7±34.1 % higher in cell number in PEEU50/Gelatin fibers after 7 days of cell culture when compared to PEEU fibers without coating. In this work, we demonstrate that water-soluble gelatin can be incorporated as the outer shell of a polymer fiber via molecular entanglement, with a sustained presence and role in enhancing stem cell attachment and proliferation.
具有核壳结构的微纤维可以通过同轴静电纺丝生产，从而可以使外层功能化，接上生物活性分子。在这项研究中，我们采用同轴静电纺丝技术，将热塑性可降解聚酯醚聚氨酯（PEEU）与明胶共混，制备出纤维网。PEEU 由不同 PPDO 与 PCL 重量比的聚对二氧环己酮（PPDO）和聚己内酯（PCL）段组成。我们所制备的 PEEU 纤维在 37°C 的干燥状态下，直径为 1.3±0.5μm，弹性模量约为 5.1±1.0MPa。而 PEEU/明胶核壳纤维在 37°C 的干燥状态下，直径为 1.5±0.5μm，壳层明胶含量为 12±6wt%，弹性模量为 15.0±1.1MPa，在 37°C 水合时弹性模量低至 0.7±0.7MPa。同轴静电纺丝能够使明胶壳均匀地分布在整个微纤维上。在 37°C 的磷酸盐缓冲盐水（PBS）中孵育 7 天后，接枝荧光素（FITC）的明胶仍稳定存在于 PEEU 纤维上。PEEU 纤维表面的明胶涂层促进了人脂肪来源间充质干细胞（hADSC）的黏附，与未涂层的 PEEU 纤维相比，在细胞培养 7 天后，细胞数量增加了 81.7±34.1%。在这项工作中，我们证明了水溶性明胶可以通过分子缠结作为聚合物纤维的外壳，在维持存在的情况下发挥作用，促进干细胞的黏附和增殖。
