基于连笔直写的微结构血管支架体外测评

摘要

目的 评价基于连笔直写的生命体微结构成形技术制备的管状支架的力学性能及其生物相容性.方法 对该血管支架采用径向顺应性、缝合强度、爆破压力等力学性能检测;通过溶血率、体外动态凝血实验、血小板黏附实验进行血液相容性的分析;采用细胞培养MTT法及细胞形态学观察方法,研究其细胞相容性.结果 血管支架的径向顺应性为(4.03±0.56)%/100mmHg,缝合强度为(204.5±72.1)N/cm2,爆破压力约为(102±8)kPa;支架的溶血率为1.75%,小于ISO规定的5%;在体外动态凝血实验中,血管支架的抗凝血性能显著优于对照组载玻片(P＜0.05),而且扫描电镜观察到血小板黏附较少,显示出该血管支架具有良好抗凝血性能;MTT比色法结果显示其细胞毒性为0～1级;细胞形态学观察显示L929细胞在该血管支架膜片的浸提液中呈梭形或三角形,贴壁良好.结论 该血管支架具有良好的力学性能、血液相容性和细胞相容性,可以满足组织工程血管支架的要求.%Objective To evaluate the mechanical properties and biocompatibilities of the vascular scaffold manufactured with micro-tip direct writing technology. Methods Mechanical properties of the vascular scaffold were measured by the parameters of radial compliance, suture strength and bursting pressure separately. The blood compatibilities of the scaffold were analyzed by hemolytic rate test,in vitro dynamic blood clotting test, ant platelet adhesion experiment. Cell compatibility was evaluated by MTT measurement and morphological observation. Results The scaffold showed radial compliance of ( 4. 03 ± 0. 56) ％/100mmHg, burst strength of ( 102 ± 8) kPa , and suture retention strength of (204. 5 ±72. 1) N/cm2. The hemolytic rate was 1. 75％ , being lower than 5％ , which was ruled by ISO. The anti-coagulant property of the scaffolds was significantly better than that of glass slides in dynamic coagulation tests( P ＜ 0. 05 ) . The anti-coagulant property of the scaffold was also confirmed by less platelet adhesion. MTT assay results showed that the cytotoxic grade of the novel polyurethane was from 0 to 1. Cellmorphology observation showed that the L929 cells were spindle-shaped or triangular with good stretch. Conclusion The scaffold manufactured with the new technique processes good mechanical properties, blood compatibility and cell compatibility.