近年來，組織工程學於器官損傷及功能修復為重要的研究方向，許多研究會結合支架、細胞及生長因子去進行組織修復，目的為提供細胞良好生長環境，進而恢復受損區域之功能性。天然支架中之生物支架多為利用生物體的組織或器官進行移植，但於臨床上若使用異種生物之組織器官移植會造成免疫排斥或細菌感染之問題，又同種生物之組織器官相對稀少且珍貴，因此發展出去細胞之方法，將取得的異種生物組織器官進行去細胞留下細胞外基質支架，以補足同種稀少的問題。然而移植後雖然擁有良好的生物相容性，但去細胞過程有細菌感染的可能，因此出現無菌的細胞培養再去細胞之方法製備支架。許多文獻指出，間葉幹細胞能夠分泌大量的細胞外基質以及細胞激素，藉由培養間葉幹細胞，並進行去細胞後，取得細胞所分泌之細胞外基質支架，可用於培養病患之目標細胞，進而治療受損區域，然而傳統方式製備支架耗時長，無法及時給予所需之去細胞支架。為了解決製備耗時長之問題，本研究所使用甲基纖維素水膠系統使間葉幹細胞自我貼附並沉降細胞外基質，短時間便能製作完細胞球，並且利用界面活性劑之方式進行去細胞，以定量方式確認DNA之低殘留，並且以西方墨點法、免疫螢光染色等方式確認細胞外基質及細胞激素之保存。此外，本研究使用大分子擁擠現象原理，增加間葉幹細胞之細胞外基質沉降及細胞激素含量。體外實驗部分，本研究利用共培養之方式觀察去細胞支架對於細胞增殖、細胞活性之提升；而利用去細胞支架上之黏附點位，可使間葉幹細胞及內皮細胞貼附於細胞支架並且使細胞利用基質成分，造成支架之形狀改變。體內實驗部分，本研究將去細胞支架與Matrigel移植進裸鼠體內，觀察到宿主細胞會遷徙至去細胞支架上，說明支架能提供宿主細胞生長環境。

Scaffolds for tissue engineering aim to mimic the native extracellular matrix (ECM) that provides both physical support and biochemical cues to modulate multiple cell behaviors. In current tissue engineering research, however, the majority of biomaterials are employed as scaffolds merely because of their structural and mechanical properties, thus failing to deliver the essential niche for encouraging tissue regeneration. In this study, we developed a mesenchymal stem cell (MSC)-derived three-dimensional (3D) matrix that contains precise matrix composition and abundant inherent growth factors as a bioactive tissue-engineering scaffold system that can closely recapitulate the native ECM. MSCs are well known to modulate multiple regenerative-relevant cell behaviors by their active paracrine signaling, which can be further enhanced after assembly into 3D cell spheroids. Additionally, artificial niche established by macromolecular crowding effect was applied to harness the deposition of matrix and soluble factors. Moreover, the protocol of decellularization was optimized to eliminate intracellular materials while maximizing the preservation of 3D matrix structure and the inherent bioactive compositions. Our in vitro results demonstrated that the 3D MSC spheroid-derived matrix effectively served as bioactive scaffolds for cell adhesion and proliferation. After subcutaneous transplantation, the fabricated ECM scaffolds could recruit host cells and promote local vascularization. We anticipate that the developed 3D MSC spheroid-derived ECM scaffold system may potentially promote tissue repair by engineering a proregenerative microenvironment.

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