去细胞心内膜作为小口径组织工程血管内膜层材料的研究

Using acellular endocardium as a scaffold for the intima of small-caliber vascular grafts

目的:探讨去细胞心内膜作为新型生物材料构建小口径组织工程血管内膜层的可行性。方法:2018年1月至2019年12月,分离新鲜猪心内膜,用包含DNase Ⅰ、RNaseA的Triton X-100+十二烷基硫酸钠(SDS)去细胞液进行消化,获得去细胞心内膜材料,并检测其形态学和力学特征。将去细胞心内膜内表面接种CD34 +骨髓干细胞构建小口径血管,连接脉冲生物反应器,研究其在模拟动态状态下对细胞的黏附力。 结果:去细胞液可完全去除材料中的细胞成分,去细胞心内膜与新鲜心内膜弹性模量分别为(2.35±0.41) MPa和(2.13±0.36) MPa( n=3, P>0.05),对比差异无统计学意义,显示了良好的力学顺应性。对CD34 +骨髓干细胞具有良好的黏附性。在脉冲生物反应器下培养,当灌注压为40 mmHg(1 mmHg=0.133 kPa)时脱落细胞数为(15.84±4.22)×10 2( n=3, P>0.05),对比10、20 mmHg时无显著增加,细胞在去细胞心内膜表面存留较好,并形成完整、融合的细胞单层。 结论:去细胞心内膜具有独特表面形态结构和良好的力学顺应性等特征,有利于提高其在动态血流下对CD34 +细胞黏附和存留,可作为有用的小口径组织工程血管内膜层材料。

Objective To investigate the feasibility of using acell-ular endocardium as a new biomaterial for the intima of small-caliber vascular grafts and itsproperty.Methods Fresh porcine endocardium was isolated and digested with Triton X-100+sodium dodecyl sulfate(SDS)solution containing DNaseⅠand RNase A to obtain acellular endocardial material,and its morphological and mechanical characteristics were detected.CD34+bone marrow stem cells were seeded on the inner surface of acellular endocardium to construct a small caliber blood vessel,which was connected with a pulse bioreactor to study its adhesion to cells under simulated dynamic state.Results The cell components in the material could be completely removed by acellular solution.The elastic modulus of acellular endocardium and fresh endocardium were(2.35±0.41)MPa and(2.13±0.36)MPa respectively(n=3,P>0.05).There was no significant difference between them,showing good mechanical compliance.It has good adhesion to CD34+bone marrow stem cells.When the perfusion pressure was 40 mmHg(1 mmHg=0.133 kPa),the number of exfoliated cells was 1584±422(n=3,P>0.05),no significant increase compared with the former.The cells on the acellular endocardium remained well and grow into a confluent endothelial layer.Conclusion Acellular endocardium is beneficial for cell adhesion under dynamic fluid perfusion.Thus,it can be used as a useful biomaterial for the intima of tissue engineered small-caliber vascular grafts.