施加刺激以促進人類脂肪幹細胞軟硬骨分化

Abstract

近年來，生醫組織工程發展迅速，許多研究致力於研發新的生物支架，提供細胞更多載體的選擇。生物支架的原料通常分為天然高分子，如: 明膠、角蛋白、幾丁質等，或是合成高分子，如: 聚甲基丙烯酸甲酯、聚乙烯等，前者有較高的生物相容性與生物降解性，而後者則可以依照需求合成具有特定性質的材料，用途更加廣泛。除此之外，越來越多的文獻證明施加外力、電刺激有助於促進幹細胞的硬骨、軟骨組織分化，因此生物支架不僅只是作為細胞載體，更可以在特定環境下模擬體內組織增生的狀況。 本研究將分為兩個部分，第一個部分為施加外力於載有人類脂肪幹細胞的酵素交聯明膠水凝膠進行軟骨分化。將人類脂肪幹細胞先透過特定的模具製成細胞球，將其載入以酵素交聯製成的明膠水凝膠中，再置於動態培養擠壓裝置中進行軟骨分化，模擬細胞在體內受力環境下進行軟骨分化，並預期施加外力刺激能促進人類脂肪幹細胞的分化效果。 第二個部分為導電高分子聚(3,4-乙烯基二氧噻吩):聚(苯乙烯磺酸鹽) (PEDOT:PSS)結合新型二維奈米導電材料鈦碳化物(MXene, Ti3C2X3) 製備三維導電支架。現有文獻指出MXene具有良好的生物相容性、骨誘導性和骨再生活性，因此將PEDOT:PSS與MXene所作成的三維支架被應用於人類脂肪幹細胞的硬骨分化，並透過電刺激提升硬骨分化的效果。研究結果顯示人類脂肪幹細胞可以成功地在支架內部生長，說明此導電三維支架的低細胞毒性，並預期最終硬骨分化特定基因能有顯著差異，證明PEDOT:PSS與MXene的三維導電支架可作為電刺激應用於人類脂肪幹細胞硬骨分化的平台。

Recently, biomedical tissue engineering has developed rapidly, and many studies have been devoted to developing new biological scaffolds for cells. The materials of biological scaffolds are usually made of two kinds of polymers. One is natural polymers such as gelatin, keratin, chitin, etc. The other is synthetic polymers such as polymethyl methacrylate, polyethylene, etc. The former has high biocompatibility and biodegradability, and the other can synthesize materials with specific properties according to needs, which is more widely used. In addition, there are more studies have shown that the application of external force and electrical stimulation promotes stem cells chondrogenic and osteogenic differentiation. Therefore, bioscaffolds are not only used as cell carriers but can also simulate the state of tissue proliferation in vivo in a specific environment. This study has two parts, and the first part is the chondrogenic differentiation of human adipose-derived stem cells-laden enzyme-crosslinked gelatin hydrogel with external force. The human adipose-derived stem cells (hASCs) were first made into cell spheroids through a specific mold and loaded into gelatin hydrogels made of enzyme cross-linking. And then placed them in a dynamic culture compression device for chondrogenic differentiation, which simulates cell the chondrogenic differentiation in vivo. It is expected that the application of external force compression can promote the differentiation effect of hASCs. The second part is about poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) combined with a new two-dimensional nano-conducting material titanium carbide (MXene, Ti3C2X3) to prepare three-dimensional (3D) conductive scaffolds. Some studies showed that MXene has good biocompatibility, osteoinductivity, and bone regeneration activity. PEDOT:PSS/MXene scaffold was applied to the osteogenic differentiation of hASCs, and electrical stimulation was used to enhance the osteogenic differentiation. The results showed that the conductive scaffold has low cytotoxicity to hASCs, which could grow and migrate in the 3D scaffold. It is expected that osteogenic specific gene markers could be significantly different, making the PEDOT:PSS/MXene scaffold an excellent platform for the osteogenic differentiation of hASCs with electrical stimulation.