基于脾脏脱细胞支架构建组织工程肝脏的体内植入策略

Implantation strategy of tissue-engineered liver based on decellularized spleen matrix in rats

目的体外构建基于脾脏脱细胞支架的组织工程肝脏,并探索其理想的体内植入策略。方法获取健康SD大鼠脾脏,采用低温冻融结合十二烷基硫酸钠灌注法制备脾脏脱细胞支架(DSM)。Seglen改良两步胶原酶灌注法获取大鼠原代肝细胞,经脾动脉再植入DSM内体外构建组织工程肝脏。以SD大鼠为受体,比较异位血管吻合移植、肝断面缝合移植、肝内嵌入移植以及肠系膜包裹移植4种策略的优缺点。结果肝细胞支架种植率为(74.5±7.7)%,HE染色与扫描电镜显示细胞状态良好,免疫荧光染色证实细胞正常表达ALB、G6Pc。异位血管吻合移植手术难度高,围手术期死亡率高达33.3%,术后6 h支架内形成大量血栓;肝断面缝合无法迅速建立充分血供,术后3 d未见成形移植物;肝内嵌入移植法细胞最长可存活14 d;肠系膜包裹移植术后14 d时支架内细胞存活率为(38.3±7.1)%。结论利用DSM构建的组织工程肝脏能部分表达肝细胞特异性功能,肠系膜包裹移植策略简单安全有效,是目前可行的体内移植方式。

Objective To explore the optimal implantation strategy of tissue-engineered liver（TEL） constructed based on decellularized spleen matrix（DSM） in rats. Methods DSM was prepared by freeze-thawing and perfusion with sodium dodecyl sulfate（SDS） of the spleen of healthy SD rats. Primary rat hepatocytes isolated using modified Seglen 2-step perfusion method were implanted into the DSM to construct the TEL. The advantages and disadvantages were evaluated of 4 transplant strategies of the TEL, namely ectopic vascular anastomosis, liver cross-section suture transplantation, intrahepatic insertion and mesenteric transplantation. Results The planting rate of hepatocytes in the DSM was（74.5 ± 7.7）%. HE staining and scanning electron microscopy showed satisfactory cell status, and immunofluorescence staining confirmed the normal expression of ALB and G6 Pc in the cells. For TEL implantation, ectopic vascular anastomosis was difficult and resulted in a mortality rate of 33.3% perioperatively and massive thrombus formation in the matrix within 6 h. Hepatic cross-section suture failed to rapidly establish sufficient blood supply, and no viable graft was observed 3 days after the operation. With intrahepatic insertion method, the hepatocytes in the DSM could survive as long as 14 days. Mesenteric transplantation resulted in a hepatocyte survival rate of（38.3＋7.1）% at 14 days after implantation. Conclusion TEL constructed based on DSM can perform liver-specific functions with a good cytological bioactivity. Mesenteric transplantation of the TEL, which is simple,safe and effective, is currently the optimal transplantation strategy.