| Summary: | 碩士 === 國立臺灣大學 === 醫學工程學研究所 === 101 === Permanent hypoparathyroidism is one of the endocrine disorders that are difficult to treat medically. Since hypoparathyroidism rarely is a life-threatening condition, systemic immunosuppression for recipients of allo-transplants are not justified. Coating the allo-transplanted tissue with a semipermeable membrane to protect the tissue from immune rejection is an alternative. In this study, oxidized chitosan cross-linked with laminin is prepared for microencapsulation of parathyroid tissue fragments. The parathyroid tissue particles with oxidized chitosan/laminin are dropped in sodium tripolyphophate solution. Tripolyphophate ion, the polyanion, would interact electrostatically with the cationic chitosan and become hydrogel to enclose the tissue particle. In the material analysis, oxidized chitosan/laminin hydrogel maintained about 80 % mass and it’s morphology in PBS until the 28th day. The material in vitro tests also showed that hydrogel had good biocompatibility and low cytotoxicity. The microencapsulation of parathyroid tissue in vitro study revealed that the hydrogel was freely permeable to the human parathyroid hormone and responded to different calcium concentration in the ex vivo test. The histological evaluation showed that the capsular hydrogel membrane were not affective to the chief cells which are the main secretory cell in the parathyroid glands. In animal study, hypocalcemia rats were induced successfully but the encapsulated tissue particles implanted were not functional in vivo. The result demonstrated that the animal model in this study must be improved.
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