人類纖維母細胞與聚胺酯水膠經3D生物列印進行細胞重新編程及類神經結構製備

Abstract

Forkhead box D3 (FoxD3) 是一種轉錄因子與神經脊標記基因，被報導其能將人類纖維母細胞重新編程為神經脊細胞。在此研究中，一種具生物相容性的新 熱敏感型聚胺酯水膠被合成，並以此 PU 水膠作為 3D 列印之生物墨水。將 FoxD3 質粒與人類纖維母細胞混入 PU 水膠中再經由針頭共同擠壓以達到細胞轉染效 果。以兩種 PU 水膠做比對，探討水膠的流變特性包含模數、凝膠時間及剪切力 對於轉染效率的影響，並算出對應的剪應率及剪切力，實驗結果以 PU1500 具有 較好的轉染效果。在剪切力~190 Pa 進行轉染下，基因表現結果顯示人類纖維母 細胞能重新編程為類神經脊幹細胞，同時具有不錯的細胞存活率。隨後進一步結 合 3D 列印機，探討不同剪切力對於轉染率及細胞長期增生的影響，並以列印支 架的方式轉染後進行 12 天神經誘導培養，西方墨點法觀察後續蛋白表現證明細 胞確實能經誘導分化為類神經細胞。此類神經結構有望在未來應用在客製化之神 經修復上。

3D bioprinting is a technique which enables the direct printing of biodegradable materials with cells into 3D tissue. So far there is no cell reprogramming in situ performed with the 3D bioprinting process. Forkhead box D3 (FoxD3) is a transcription factor and neural crest marker, which was reported to reprogram human fibroblasts into neural crest stem-like cells. In this study, we synthesized a new biodegradable thermoresponsive waterborne polyurethane (PU) gel as a bioink. FoxD3 plasmids and human fibroblasts were co-extruded with the PU hydrogel through the syringe needle tip for cell reprogramming. The rheological properties of the PU hydrogel including the modulus, gelation time, and shear thinning were optimized for the transfection effect of FoxD3 in situ. The corresponding shear rate and shear stress were examined. Results showed that human fibroblasts could be reprogrammed into neural crest stem-like cells with high cell viability during the extrusion process under an average shear stress ~190 Pa. We further translated the method to the extrusion-based 3D bioprinting, and demonstrated that human fibroblasts co-printed with FoxD3 in the thermo-responsive PU hydrogel could be reprogrammed and differentiated into a neural-tissue like construct at 14 days after induction. The neural-like tissue construct produced by 3D bioprinting from human fibroblasts may be applied to personalized drug screening or neuroregeneration.