NMI Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstrasse 55, 72770 Reutlingen, Germany.
Institute of Biomedical Engineering, Department for Medical Technologies & Regenerative Medicine, Eberhard Karls University Tübingen, 72076 Tübingen, Germany.
J Mater Chem B. 2023 Mar 8;11(10):2207-2218. doi: 10.1039/d2tb02602c.
Electrospinning has become a well-established method for creating nanofibrous meshes for tissue-engineering applications. The incorporation of natural extracellular components, such as electrospun pure collagen nanofibers, has proven to be particularly challenging, as electrospun collagen nanofibers do not constitute native collagen fibers anymore. In this study, we show that this detrimental effect is not only limited to fluorinated solvents, as previously thought. Rat tail collagen was dissolved in acetic acid and ethanol and electrospun at various temperatures. Electrospun collagen mats were analyzed using circular dichroism, enzymatic digestion, SDS-PAGE, western blotting, and Raman spectroscopy and compared to heat-denaturated and electrospun collagen in HFIP. Our data suggest that even non-fluorinated electrospinning solvents, such as acid-based solvents, do not yield structurally intact fibers. Interestingly, neither epithelial cells nor fibroblasts displayed a different cellular response to electrospun collagen compared to collagen-coated polyurethane scaffolds in F-actin staining and metabolic analysis using fluorescent lifetime imaging. The disruption of the structural integrity of collagen might therefore be underestimated based on the cell-material interactions alone. These observations expose the larger than anticipated vulnerability of collagen in the electrospinning process. Based on these findings, the influence of the electrospinning process on the distinct biochemical properties of collagen should always be considered, when ECM-mimicking fibrous constructs are manufactured.
静电纺丝已成为用于组织工程应用的创建纳米纤维网的一种成熟方法。已经证明，掺入天然细胞外成分（如纯胶原蛋白纳米纤维的静电纺丝）特别具有挑战性，因为静电纺丝胶原蛋白纳米纤维不再构成天然胶原蛋白纤维。在这项研究中，我们表明，这种有害影响不仅限于以前认为的氟化物溶剂。将鼠尾胶原蛋白溶解在乙酸和乙醇中，并在不同温度下进行静电纺丝。使用圆二色性、酶消化、SDS-PAGE、Western blot 和拉曼光谱分析静电纺丝胶原蛋白垫，并与 HFIP 中的热变性和静电纺丝胶原蛋白进行比较。我们的数据表明，即使是非氟化物静电纺丝溶剂，如基于酸的溶剂，也不能产生结构完整的纤维。有趣的是，在用 F-肌动蛋白染色和荧光寿命成像进行代谢分析时，上皮细胞和成纤维细胞对静电纺丝胶原蛋白的细胞反应与胶原蛋白涂覆的聚氨酯支架没有不同。因此，仅基于细胞-材料相互作用，胶原蛋白结构完整性的破坏可能被低估。这些观察结果暴露了胶原蛋白在静电纺丝过程中比预期更大的脆弱性。基于这些发现，在制造模仿细胞外基质的纤维结构时，应始终考虑静电纺丝过程对胶原蛋白的独特生化特性的影响。
