Monfette Vincent, Choinière William, Godbout-Lavoie Catherine, Pelletier Samuel, Langelier Ève, Lauzon Marc-Antoine
Department of Chemical Engineering and Biotechnological of Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.
Department of Electrical Engineering and Informatics Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.
J Funct Biomater. 2023 Jun 20;14(6):330. doi: 10.3390/jfb14060330.
Peripheral nerve injuries (PNIs) are detrimental to the quality of life of affected individuals. Patients are often left with life-long ailments that affect them physically and psychologically. Autologous nerve transplant is still the gold standard treatment for PNIs despite limited donor site and partial recovery of nerve functions. Nerve guidance conduits are used as a nerve graft substitute and are efficient for the repair of small nerve gaps but require further improvement for repairs exceeding 30 mm. Freeze-casting is an interesting fabrication method for the conception of scaffolds meant for nerve tissue engineering since the microstructure obtained comprises highly aligned micro-channels. The present work focuses on the fabrication and characterization of large scaffolds (35 mm length, 5 mm diameter) made of collagen/chitosan blends by freeze-casting via thermoelectric effect instead of traditional freezing solvents. As a freeze-casting microstructure reference, scaffolds made from pure collagen were used for comparison. Scaffolds were covalently crosslinked for better performance under load and laminins were further added to enhance cell interactions. Microstructural features of lamellar pores display an average aspect ratio of 0.67 ± 0.2 for all compositions. Longitudinally aligned micro-channels are reported as well as enhanced mechanical properties in traction under physiological-like conditions (37 °C, pH = 7.4) resulting from crosslinking treatment. Cell viability assays using a rat Schwann cell line derived from sciatic nerve (S16) indicate that scaffold cytocompatibility is similar between scaffolds made from collagen only and scaffolds made from collagen/chitosan blend with high collagen content. These results confirm that freeze-casting via thermoelectric effect is a reliable manufacturing strategy for the fabrication of biopolymer scaffolds for future peripheral nerve repair applications.
周围神经损伤（PNIs）对受影响个体的生活质量有害。患者常常会留下影响其身体和心理的终身疾病。尽管供体部位有限且神经功能只能部分恢复，但自体神经移植仍是周围神经损伤的金标准治疗方法。神经引导导管被用作神经移植替代物，对于修复小的神经间隙很有效，但对于超过30毫米的修复则需要进一步改进。冷冻铸造是一种有趣的制造方法，用于构思用于神经组织工程的支架，因为所获得的微观结构包含高度排列的微通道。目前的工作重点是通过热电效应而非传统的冷冻溶剂进行冷冻铸造，制备由胶原蛋白/壳聚糖混合物制成的大型支架（长度35毫米，直径5毫米）并对其进行表征。作为冷冻铸造微观结构参考，使用由纯胶原蛋白制成的支架进行比较。对支架进行共价交联以在负载下具有更好的性能，并进一步添加层粘连蛋白以增强细胞相互作用。所有组合物的层状孔微观结构特征显示平均纵横比为0.67±0.2。还报道了纵向排列的微通道以及交联处理在生理条件（37°C，pH = 7.4）下牵引时增强的机械性能。使用源自坐骨神经的大鼠雪旺细胞系（S16）进行的细胞活力测定表明，仅由胶原蛋白制成的支架与由高胶原蛋白含量的胶原蛋白/壳聚糖混合物制成的支架之间的支架细胞相容性相似。这些结果证实，通过热电效应进行冷冻铸造是一种可靠的制造策略，可用于制造用于未来周围神经修复应用的生物聚合物支架。
