Cryopreserved Heart Valves with Repaired Matrix Metabolism

背景：低温保存瓣膜的耐久性取决于成纤维细胞的活力，成纤维细胞可以重塑基质组装。我们前期的研究表明，低温保存的瓣膜在冻融过程中，内皮细胞和成纤维细胞不可避免地受到损伤，胶原活化，胶原合成的潜在降解，导致瓣膜基质的破坏。目的：本研究旨在观察冷冻保存的同种异体瓣膜组织培养解冻后是否能恢复细胞活力方法：将人脐静脉内皮细胞（HUVECs）和猪半月瓣用程序冷冻箱冷冻，然后立即浸入液氮冷冻箱（-196℃）的气相中，保存1-14 d后立即解冻，培养1-14 d。日 ...更多信息 根据细胞质酯酶活性、线粒体脱氢酶活性和一氧化氮产生量分析标本。采用激光共聚焦显微镜扫描观察瓣膜形态。冻存的稀疏分布的HUVECs在培养2周后，培养的HUVECs的线粒体脱氢酶活性和一氧化氮产生恢复到新鲜HUVECs的水平。2.激光共聚焦显微镜扫描显示，培养的猪瓣膜中有丰富的活细胞，线粒体脱氢酶活性恢复。结论：本研究证明，在冻融过程中严重损伤的心脏瓣膜经2周组织培养后得到修复，并恢复到与新鲜瓣膜相同的活性。为了更好地保护同种异体移植物，更好地应用于临床，有必要进一步检查修复后的活性瓣膜的抗血栓性和免疫原性。少

Backgrounds: Durability oh the cryopreserved valves has heard of depending on the fibroblast viability, which can remodel the matrix assembly. Our previous study suggests the possibility that the cryopreervation and thawing process cause the inevitable damage of endothelium and fibroblast, the collagenoltic activation and the latent degradation of collagen synthesis in a cryopreserved valve,which lead to the destruction of the valve matrix.Objective: The present investigation was to undertaken to examine whether the tissue culture of cryopreserved allograft valves after thawing would recover the cellular viability and matrix matabolism of them at the level of fresh valves or not.Methods: Human umbilical vein endothelial cells (HUVECs) and the porcine semilunar valves were frozen with a programmed freezer, and then immediately immersed in the vapor phase of a liquid nitrogen freezer (-196℃), After 1-14 days of storage, the specimens were thawed immediately,and cultured for 1-14 days. Th … More e specimens were analyzed based on the cytosolic esterase activity, the mitochondria dehydrogenase activity, and the nitric oxide production. The valves were observed by confocal laser microscopic scanning.Results: 1. Cryopreserved sparsely populated HUVECs in a dish spread all over after 2-week culture, and the mitochondrial dehydrogenase activity and nitric oxide production of cultured HUVECs were recovered at the level of those of fresh HUVECs. 2. Rich viable cells were observed in the cultured porcine valves by confocal laser microscopic scanning, and the mitochondrial dehydrogenase activity of the cultured valves was recovered.Conclusion: This study demonstrated that the heart valve damaged seriously during the cryopreservation and thawing process was repaired for 2-week tissue culture and became viable as same as fresh valves. Further examination for the antithrombogenicity and the immunogenicity of the repaired viable valve after implantation will be necessary to improve the allograft preservation for better clinical use. Less