微量抗冻剂降温法对提高深低温冻存角膜内皮细胞活性的作用

Effects of "dry-cooling" on alleviate cryopreserved cornead endothelium viability

目的:为排除抗冻剂溶液在深低温角膜保存及复温解冻过程中对热量传递的阻碍,更精确地探索角膜本身真正的最适宜降温速率,及有利于快速复温解冻。方法:在降温前倒干抗冻剂再降温冷冻,即所谓的"干燥降温法"。结果:角膜在2.5ml抗冻剂中降温冻存时,以1.0℃/分及1.5℃/分速率降温内皮细胞存活率及密度最高,分别达90.7%,91.4%及2784/mm^2,3048/mm^2;而由"干燥降温法"冻存时,以0.5℃/分及1.0℃/分速率降温内皮细胞存活率及密度最高,分别达92.5%,94.5%及2842/mm^2,3012/mm^2。结论:角膜组织本身真正的最适宜降温速率为0.5～1.0℃/分。采用干燥降温法,不但能使角膜真正以最佳降温速率降温,而且有利于快速复温解冻,有助于提高冻存的角膜内皮细胞活性。

Purpose: To eliminate the effects of volume of extracellular fluid on thermal conduction during corneal cryopr-eservation, and then assess accurately the proper cooling rate for corneas themselves and facilitate fast thawing. Methods: Corneas were frozen in drycontainers with only the minimum quantity of extracellular fluid, which was called "dry-cooling" . Results; When corneas were frozen in 2. 5ml cryoprotectant, cooling rate 1.0℃/min, and 1.5 ℃ /min produced the greatest density and highest survival rate of endothelial cells, and it was quite clear that optimum survival rate and density was achieved at 0.51/ min and 1 .0℃/min when in dry cooling. Conclusion:The real and most suitable cooling rate for corneas themselves was 0.5-1 .0℃/min. So-called dry-cooling makes it possible that corneas are programmaticly cooled at the best cooling rate for corneas themselves and fast thawed,which is helpful in alleviating cryopreserved corneal endothelinm viability.