组织工程心脏瓣叶皮下包埋实验

目的 探讨体外生成的组织工程心脏瓣叶在体内可能存在的组织活性。方法 裸小鼠12只，将体外培养的种植有平滑肌／成纤维及内皮细胞的瓣叶（实验组）和未种植细胞的支架片（对照组）包埋于裸小鼠背部皮下，观察支架片局部皮肤变化。分12、14、21、28d4个时间段各处死3只小鼠，大体观察、组织学检查。结果 包埋12、14d，活体显示实验组局部皮肤色泽红润，大体标本呈自体组织色泽。对照组活体局部皮肤及大体标本均苍白。HE染色结果显示，包埋12d。实验组细胞数量比对照组多，材料中部有肌纤维形成。对照组细胞数少，无肌纤维形成。至第28天．两组细胞数量均明显增加，对照组细胞仍较少。实验组显示纤维包膜内有肌纤维形成，对照组无。VG染色结果显示，种植后第12天．实验组有红染胶原纤维形成。对照组无明显的阳性染色胶原纤维。结论 组织工程心脏瓣叶在体内具有组织活性，如进行自体瓣叶原位移植可能具备生长能力。

Subcutaneous implantation of tissue-engineered heart valve leaflets in nude mice

Objective To investigate the viability of tissue-engineered heart valve leaflets prepared with cell-polymer constructs in nude mice.Methods Sheep endothelial cells and smooth muscle cells/fibroblasts were seeded on patches of PHA and implanted subcutaneously in athymic mice(BALB/C).The cell-polymer constructs were harvested 12,14,21 and 28 days after implantation.Results Fourteen days after implantation,the cell-polymer constructs exhibited similar color with the autologous tissues,and HE staining showed more numerous cells in the implant.At 28 days following implantation,muscular fibers were formed in the cell-polymer constructs.V-G staining showed positive collagen staining in the implant at 12 days after implantation,while the control implants retrieved 28 days after implantation did not show extensive tissue formation or muscular fiber formation.Conclusion The cell-polymer constructs can survive in vivo and has the potential to grow into autologous valve leaflets in the nude mice.