再生醫學已被廣泛應用在器官的修復與疾病的治療，近來利用生物材料作為細胞支架已證實能增加細胞療法效率。生物材料來源包括天然和合成聚合物、陶瓷和複合材料。其中以細胞外基質製備的天然生物材料，與身體組織結構與成分相似度高，有較高的生物相容性，更常被應用在器官修復的用途。細胞外基質是由細胞所分泌的物質組成的三維結構，其成分是包含多種蛋白質與醣類，細胞外基質除了提供細胞生長所需的支架並能明顯地影響細胞行為，包括遷移、增值和分化，因此更是格外受到矚目。然而，細胞外基質若殘存原本的細胞將容易產生排斥的問題，因此藉由有效脫細胞方法來脫去原組織的細胞，並減少對結構與有效成分的破壞，成為此類生醫材料的最重要的課題。
本研究利用物理和化學的脫細胞方法去除豬膀胱內的細胞以獲得細胞外基質，以並分析其殘存的細胞量不致於影響免疫反應。並研究所獲得的細胞外基質有足夠的膠原蛋白可以製備水凝膠，並評估此水凝膠的生物相容性。
實驗結果顯示，豬膀胱藉由低張、高張和0.1%十二烷基硫酸鈉（Sodium dodecyl sulfate，SDS）溶液脫細胞後，每1mg的豬膀胱的dsDNA含量低於50ng，證明脫細胞對膀胱有明顯的效果。其中豬膀胱的膠原蛋白含量有700μg，明顯地高於豬的皮膚和肺臟。在比濁法動力分析可以發現細胞外基質濃度越高，相對的成膠速度也相對較快。電子顯微鏡中所觀察材料的孔洞也隨之變小。體外試驗中將HaCaT細胞加入水凝膠中並藉此評估水凝膠的毒性，實驗結果顯示，水凝膠的組別其細胞生物活性較控制組。從螢光顯微鏡及電子顯微鏡皆能觀察到細胞存在於水凝膠中，可以證明水凝膠沒有毒性。
本實驗使用的脫細胞方法成功地降低dsDNA含量並保留了其膠原蛋白含量且製備成水凝膠，，應用於細胞沒有生物毒性。後續會將水凝膠進行傷口癒合的分析，觀察對於傷口是否有癒合的作用。綜合以上的分析證明出豬膀胱有極大的潛力作為生物材料的應用，未來可以提升醫療品質並達到生物廢棄物的再利用。

Recent years, witness the intensive use of biomaterials in the field of regenerative medicine due to their unique biochemical properties. Biomaterials used in the regenerative medicine include natural, synthesized polymers, ceramics and composite materials. Extracellular matrix (ECM) is a natural material which consists of extracellular macromolecules and proteins inside a three-dimensional structure. The ECM prepared from different organs or tissues provides unique scaffolds structures and significantly affects cell behaviors. In this study, the combinative use of hypotonic, hypertonic and 0.1% SDS solution could successfully decellularize the pig bladder with less than 50ng dsDNA per mg. High collagen content was retained in the ECM with 700ug per milligram ECM dry weight. The lyophilized ECM was then used to prepare hydrogels using reported method. The turbidimetric assay indicated that ECM gels with higher concentration would lead to faster gelation rate and bigger pore sizes. The results from MTT assays showed that the hydrogels were non-toxic, with higher proliferation rate compared to that of the control group. In addition, results from DAPI and SEM pictures indicated the presence of the cells inside the hydrogels, confirming the biocompatibility of the materials.
Our research successfully decellularized pig bladder with the significant reduction in dsDNA content and high collagen retention and the hydrogels could subsequently be prepared from the retrieved decellularized ECM. In vitro experiments showed that the material was non-toxic to the cells. To get further insights into the ECM, the wound healing ability of hydrogels will be investigated in future studies. To sum up, ECM extracted from pig bladders is not only a potential candidate material in medical applications but also helps in the bio-waste recycling management.

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