微囊化大鼠肝细胞移植的组织学研究

Viability and histological changes of encapsulated rat hepatocyte after transplantation

目的 研究微囊化大鼠肝细胞腹腔移植后的存活情况以及组织学改变。方法 用二步法胶原酶门 腔静脉灌注法分离Wistar大鼠肝细胞 ,用Percoll梯度分离液纯化、海藻酸钠 氯化钡法微囊化包裹肝细胞 ,分别行腹腔注射移植 ,将纯化的肝细胞移植至SD大鼠体内 (第 1组 )、微囊化包裹的肝细胞移植至SD大鼠体内 (第 2组 )及Wistar大鼠体内 (第 3组 ) ,观察移植后各组不同时间肝细胞存活率及其组织学变化。结果 (1)移植后第 4、7d ,各组间肝细胞存活率的差异均有显著性 (P <0 .0 1) ;移植后第 14d ,第 2组与第 3组间肝细胞存活率的差异无显著性 ;(2 )移植后第 4d开始 ,微囊周围出现纤维增生现象 ,第 2组较第 3组明显。结论 微囊化可为移植的肝细胞提供免疫屏蔽作用 ,从而提高肝细胞移植的存活率 ;

Objective To study the viability and histological change of encapsulated rat hepatocytes after being transplanted into abdominal cavity of rat. Methods The two step collagenase perfusing method was used to separate hepatocytes from Wistar rat liver. The separated hepatocytes were purified with Percoll density gradient centrifugation and encapsulated by the alginate barium method. Then the purified hepatocytes were transplanted into abdominal cavity of SD rats (group 1) and the encapsulated hepatocytes were transplanted into abdominal cavity of SD rats (group 2) and Wistar rats (group 3). At different time points post transplantation, trypan blue stain exclusion was used to determine the viability of recovered hepatocytes. The histological changes of transplanted microencapsulated hepatocytes was examined using HE stain. Results Twenty four h after transplantation, the viability of hepatocytes between group 1 and group 2 showed significant difference ( P < 0.01 ), but there was no significant difference between group 2 and group 3 ( P > 0.05 ). At day 4 and day 7 after transplantation, the viability of hepatocytes showed significant difference between group 1 and group 2, and group 2 and group 3 ( P < 0.01 ). At day 14 after transplantation, no significant difference was found in the viability of hepatocytes between group 2 and group 3 ( P > 0.05 ). From day 4 post transplantation, fibrosis overgrowth was found around some microencapsules, and it was more obvious in group 2 than in group 3. Conclusions Microencapsulation can provide protection to transplanted hepatocytes from host immunorejection, and thus increase the viability of hepatocytes post transplantation. The existence of inadequately encapsulated microencapsule cause the fibrosis overgrowth around these capsules, resulting in ischemia and subsequent necrosis of the hepatocytes and decreasing hepatocyte viability.