聚乳酸/聚羟基乙酸共聚物网管支架体外预血管化及体内植入的实验研究

目的研究预血管化对含网管的多孔可降解聚乳酸/聚羟基乙酸共聚物(polylacticl/glycolicacidcopolymer,PLGA)支架血管化的影响。方法将含网管的多孔可降解PLGA支架由小鼠微血管内皮细胞预血管化,分为体外预血管化组(A组)和单纯支架组(B组)。将两组支架植入12只雌性NIH小鼠肠系膜间,分别于术后2、4周取材,行组织学及免疫组织化学观察血管化情况,并应用图像分析软件计算支架血管化面积。结果支架体外预血管化后,其网管内可见微血管内皮细胞均匀贴壁。支架植入体内2周,切片血管化面积A组为2260.91±242.35μm2与B组823.64±81.29μm2比较,差异有统计学意义(P<0.01);4周时A组为17284.36±72.67μm2与B组17041.14±81.51μm2比较,差异无统计学意义(P>0.05)。植入2周支架切片肌动蛋白阳性染色面积A组为565.22±60.58μm2与B组205.91±16.25μm2比较,差异有统计学意义(P<0.01);4周时A组为4321.09±19.82μm2与B组4260.28±27.17μm2比较,差异无统计学意义(P>0.05)。结论含网管的多孔可降解PLGA支架是一种良好的简易血管化支架模型;预血管化可以明显增强支架植入早期的血管化。

A STUDY ON IN VITRO FORCE-VASCULARIZATION AND IN VIVO VASCULARIZATION OF POROUS POLYLACTIC/GLYCOLIC ACID COPOLYMER SCAFFOLDS WITH INTERNAL NETWORK CHANNELS

OBJECTIVE: To study the influence of in vitro force-vascularization on in vivo vascularization of porous polylactic glycolic acid copolymer (PLGA) scaffolds with internal network channels (PPSINC). METHODS: After the in vitro force-vascularization of PPSINCs covered with microvessel endothelial cells (MVEC) of mice, they were divided into two groups: the force-vascularization group (group A) and the control group with only PSINCs (group B). All the PPSINCs were planted in the mesentery of 12 mice for 2 and 4 weeks, the PPSINCs were cut out, the vascularization of PPSINCs was investigated by histology and immunohistochemistry, and the vascularization area of the histologic section of the PPSINCs was measured with the computer-assistant image analysis system. RESULTS: After the in vitro force-vascularization of PPSINCs, the MVEC of the mice sticking on the channel wall could be seen. After the scaffold was implanted into the mice for 2 weeks, the vascularization area of the histologic section of PPSINCs (VA) in group A (2 260.91 +/- 242.35 microm2) was compared with that in group B (823.64 +/- 81.29 microm2), and the difference was significant in statistics (P < 0.01). The VA for 4 weeks in group A (17 284.36 +/- 72.67 microm2) was compared with that in group B (17 041.14 +/- 81.51 microm2), and the difference was not significant in statistics (P > 0.05). The area of the actin positive-staining (AA) in the histologic section of PPSINCs for 2 weeks' implantation in group A (565.22 +/- 60.58 microm2) was compared with that in group B (205.91 +/- 16.25 microm2), and the difference was significant in statistics (P < 0.01). After the implantation for 4 weeks, the VA in group A (4 321.09 +/- 19.82 microm2) was compared with group B (4 260.28 +/- 27.17 microm2), and the difference was not significant in statistics (P > 0.05). CONCLUSION: The PPSINC is a good simple scaffold model of vasculariazation. The in vitro force-vascularization can increase the in vivo vascularization of PPSINCs in the early stage.