New Method of Cryopreservation for Pancreatic Islets by Flash Freeze Apparatus

自2004年以来，日本已开始对胰岛素依赖型糖尿病（IDDM）患者进行胰岛移植。然而，由于胰岛移植的供体很少，该治疗方法尚未普及。如果不能从供体胰腺中分离出足够数量的胰岛，我们就不能进行胰岛移植。在这种情况下，我们应该冷冻保存胰岛，以备将来移植之用。胰岛的冷冻保存已经发展了几年。然而，胰岛的功能和复苏率并不完全令人满意。需要更多的研究应用于临床治疗。在本研究中，我们寻找更好的胰岛冷冻保存方法的解决方案。我们与昭和Tansan公司的胰岛保存团队共同开发了一种新的胰岛冷冻保存设备，该装置通过混合胰岛颗粒和液氮在瞬间均匀地制造胰岛的冷冻颗粒。因此，冷冻胰岛被认为在解冻后保持了胰岛的结构和分泌功能。利用该装置可以连续制备出直径为0.5mm的CP-1/RPMI 1640冷冻液冷冻颗粒，颗粒收集率达80%。然而，使用胰岛的胶体溶液，不能充分地制备冷冻颗粒，并且不能不方便地将冷冻胰岛颗粒从装置中拯救出来。目前，该装置已被改进，以克服这些问题，该装置将是一个强有力的工具，以解决一些问题，在冷冻保存胰岛。

Pancreatic islet transplantation has been performed for the patients with insulin-dependent diabetes mellitus (IDDM) in Japan since 2004. However, the treatment has not yet been popular, because donor for islet transplantation has been very few. We are not able to transplant the islets if enough population of islet is not isolated from donor pancreas. In the case, we should do cryopreservation of islet for using it in future chance of transplantation. Cryopreservation of pancreatic islet has been developed in several years. However, function and recovery rate of islet after thawing are not fully satisfied. More studies are necessary to apply to clinical treatment. In this research, we searched for a solution of better cryopreservation methods for pancreatic islet.We developed a new apparatus for cryopreservation of pancreatic islet together with the Islet Preservation Team in Showa Tansan Co., LTD. The apparatus uniformly makes freeze particles of islet in a moment by mixing islet particles and liquid nitrogen. Consequently, freeze islets are thought to keep the structure and secretion function of islet after thawed out. With this apparatus, we were able to constantly prepare 0.5mm diameter freeze particles of CP-1/RPMI1640 freeze liquid and get the particles with 80% of collecting rate. However, with colloid solution of islets, freeze particles were not sufficiently made and the freeze islet particles were not inconveniently rescued from the apparatus. Now, the apparatus has been improved to overcome these problems.This apparatus would be a potent instrument for solution of several problems in cryopreservation of pancreatic islets.