| 摘要: | 由於幹細胞能夠分化為許多不同的細胞以組成新組織，因此成為組織工程及再生醫學的新寵。但胚胎幹細來源與取得涉及道德與倫理問題，使其受到很大的限制。近來，雖有利用基因植入體細胞而產生之誘導式多能性幹細胞，但這類細胞存在著植入人體後可能轉變為癌細胞的問題。因此，從臍帶血、骨髓、經血、或脂肪等組織所取得的血液幹細胞與間葉幹細胞，變成為可以運用的幹細胞來源。所以如何由上述組織純化出血液幹細胞或間葉幹細胞便成為一關鍵技術。現雖有不同細胞分離技術。其中薄膜分離技術是由本實驗室提出且為最簡便、易保持無菌、及維持細胞活性的方法，為臨床醫師認為最具潛力的細胞分離術。計畫中，我們擬以奈米結構的特殊高分子植於薄膜上，使得幹細胞存活率提高，並調整細胞與薄膜間的親和性以進行細胞分離。如何選擇特殊高分子與其種植密度與結構來進行血液幹細胞或間葉幹細胞的分離便是本計劃探討的主軸之一。具奈米結構的高分子植入，調整了細胞與薄膜間的親和性，也改變貼附於材料表面的細胞型態，而影響幹細胞的分化。因此藉著高分子的植入，我們可以改變幹細胞的分化路徑，掌控幹細胞朝著不分化，或朝著不同組織細胞分化。所以表面奈米結構與細胞培養與基因表現之關係也是本計劃重點。同時，我們將進行血液幹細胞、間葉幹細胞與其初步分化的鑑定。也將利用改質的高分子膜來分離癌症幹細胞以協助癌症治療藥物的研發。 ; Stem cells are an attractive source of cells for tissue engineering and cell therapy (i.e., regenerative medicine using stem cells) because of their unique biological properties. There are major ongoing ethical concerns about the use of embryonic stem (ES) cells in conventional research and potential human therapies. However, stem cells have been also isolated from a variety of somatic tissues such as hematopoietic stem cells (HSCs) from umbilical cord blood and mesenchymal stem cells (MSCs) from bone marrow, umbilical cord blood, menstrual blood and tissues such as fats. Recently iPS (induced pluripotent stem) cells are developed from somatic cells with injection of genes. However, ES cells and iPS cells can be differentiated to tumors called as teratoma when they are transplanted into animal bodies. Therefore, HSCs and MSCs are the most promising cell source for tissue engineering and cell therapy in practical and clinical applications. Cell separation is a key technology in the isolation of stem cells from tissue and blood, and the transplantation of HSCs or MSCs. Techniques such as centrifugation, fluorescence activated cell sorting, magnetic cell selection, affinity column chromatography and membrane filtration are typically employed for cell separation. Membrane filtration method for stem cell purification has been developed by our group. Compared with other cell separation methods, membrane filtration is simple, and the sterility is easy to maintain during the process. Therefore, clinical doctors believe that membrane filtration is the most promising technique for bedside purification of HSCs and MSCs. In this project, we investigate the interaction between stem cells and nano-segments on the biomaterials, which contributes to the separation of the stem cells and cell survival of the stem cells. The optimal chemical structure and recognition sites of nano-segments for the purification of stem cells through the membranes will be designed in this project. We will regulate the gene expression of the stem cells by the cell culture materials where the interaction between stem cells and nano-segments regulates the morphology of the stem cells. The most appropriate biomaterials having nano-segments for the cell culture of HSCs will become clear for the increase of cell numbers of HSCs without differentiation for the clinical use of HSCs. The most appropriate biomaterials having nano-segments for the cell culture of MSCs will be designed for the differentiation of MSCs to several kinds of differentiated cells such as osteoblasts, chondrocytes, adipocytes, muscle cells and nerve cells by regulation of morphologies of MSCs on the biomaterials. We will investigate and characterize MSCs isolated from menstrual blood, and the biochemical difference between MSCs isolated from tissue (Adipose-deriped stem cells), bone marrow and menstrual blood by bioassay. We will further purify the cancer stem cells through the surface-modified membranes having nano-segments. Development of specific therapies targeted at cancer stem cells holds hope for improvement of survival and quality of life of cancer patients, especially for sufferers of metastatic disease. We would like to contribute the development of regenerative medicine and improvement of quality of life of the patients in the world from this project. ; 研究期間 9708 ~ 9807 |
