Abstract

Freeze-drying is an effective method for preservation of aortas. In order to maintain the original properties of aortas, the sublimation drying process requires accurate monitoring. In this study, we used a contactless mass measurement device to monitor drying process, porcine aortic segments were divided into four series for freeze-drying, then relevant experiments and calculations were carried out to evaluate the quality of lyophilized samples. The study found that the sublimation process could not be accurately monitored by measured temperature, however, the real-time weighing could do it well, and was suitable to judge the endpoint of primary drying. Meanwhile, the change law of sublimation temperature was obtained by quasi-steady heat transfer equations. The removal ratio of free water during the primary drying greatly affected the properties of lyophilized samples, thorough sublimation had contributed to better performance of products, especially in mechanical properties. In addition, compared with annular aortic segments, the flaky samples had better heat transfer and performed better in histological scanning.

摘要

冷冻干燥是保存主动脉的有效方法。为了保持主动脉的原始特性，升华干燥过程需要准确监测。本研究采用非接触式质量测量装置监测干燥过程，将猪主动脉节段分为四个系列进行冷冻干燥，然后进行相关实验和计算以评估冻干样品的质量。研究发现，升华过程无法通过测量的温度准确监测，但实时称重可以很好地进行，适合判断初级干燥的终点。同时，通过准稳态传热方程得到了升华温度的变化规律。