Pancreas perfusion with PFC-Unisol

描述（由申请人提供）：世界范围内的共识是胰岛移植可能被认为是治疗胰岛素依赖型糖尿病的可行选择，世界各地的许多中心正在进行临床试验。随着这种治疗糖尿病的方法转变为常规的临床护理标准，对供体胰岛的需求将会增加。此外，异种移植能否缓解人类胰腺供应不足的需求，还将取决于从源胰腺中分离胰岛的技术的效率。不幸的是，胰岛在长时间缺血后极易受到不可逆损伤，尸体胰腺的冷缺血对胰岛产量不利，因此需要新的方法来改进胰腺保存方法，以提高高质量胰岛的产量。低温已被证明是最广泛使用的器官保存方法的基础，但最好的技术仍然受到一些冷缺血性损伤的影响。缺氧仍然被认为是一个关键因素，在缺血期间试图减少氧债的一种策略是使用全氟化碳（PFC），试图增加向冷缺血器官的氧气输送。然而，将器官浸泡在水/PFC界面的双层方法仅在小动物模型中被证明是成功的。作为一种替代方法，支持这一提议的假设是，pfc将需要灌注到器官中，以向缺氧冷缺血细胞提供有效的氧气输送。拟议研究的总体目标是结合三种可能影响供体器官质量的技术，尤其是胰腺。它们是：1)低温机灌注（HMP）；ii)低温血液替代（HBS）；iii)与全氟化学品（PFC）的氧化。我们的假设是HMP与pfc增强HBS将提供更好的胰腺低温保存，我们将使用两个特定目标进行测试：第一个目标是使用Unisol- pfc建立灌注动力学，其中Unisol是专有的HBS。使用已建立的猪模型，我们的HMP与Unisol HBS的基线技术将适用于在Unisol中制备PFC乳状液（Unisol-PFC），并使用LifePort(R)灌注机确定促进有效灌注所需的灌注参数。第二个目的是评价pfc灌注对胰岛灌注后分离质量的影响。利用已建立的分叶灌注模型，目的是比较用uniol - pfc与单独使用Unisol灌注的猪胰腺叶分离胰岛的产量和质量。这种方法的预期结果是，pfc增强灌注的实施将提供一个可持续的氧库，以满足在长时间冷缺血储存期间器官显著减少的需求。反过来，这将为高能磷酸盐再生提供手段，避免器官在缺氧和缺血期间被迫切换到无氧糖酵解的众所周知的后果。虽然这些研究是专门针对胰岛移植的临床需求而设计的，但潜在的技术发展将很容易适用于所有可移植器官。

DESCRIPTION (provided by applicant): There is a worldwide consensus that islet transplantation may be considered a viable option for the treatment of insulin-dependent diabetes mellitus, and clinical trials are underway at many centers around the world. As this approach for curing diabetes transitions into a routine clinical standard of care so the demand for donor islets will escalate. Moreover, the potential for xenotransplantation to relieve the demand on an inadequate supply of human pancreases will also be dependent upon the efficiency of techniques for isolating islets from the source pancreases. Unfortunately, islets are highly vulnerable to irreversible damage after prolonged ischemia, and cold ischemia of the cadaveric pancreas is detrimental to islet yield such that new approaches are needed for improved methods of pancreas preservation to increase the yields of high quality islets. Hypothermia has proved to be the bed-rock of the most widely used methods of organ preservation but the best techniques are still subject to some cold ischemic injury. Oxygen deprivation is still regarded as a key factor and one strategy adopted to try to reduce the oxygen debt during ischemia has been to use perfluorocarbons (PFC) in an attempt to augment oxygen delivery to the cold ischemic organ. However, the Two-Layer Method, in which the organ is submerged at the aqueous/PFC interface, has only proved successful in small animal models. As an alternative approach the hypothesis underpinning this proposal is that PFCs will need to be perfused into the organ to provide effective oxygen delivery to the hypoxic cold ischemic cells. The general aim of the proposed research is to combine three technologies that could impact the quality of donor organs, and notably pancreases. These are: i) hypothermic machine perfusion (HMP); ii) hypothermic blood substitution (HBS); and iii) oxygenation with perfluorochemicals (PFC). Our hypothesis that HMP with PFC-augmented HBS will provide superior hypothermic preservation of pancreases will be tested using two specific aims: The first aim will be to establish perfusion dynamics with Unisol-PFC, where Unisol is a proprietary HBS. Using an established porcine model, our baseline technology of HMP with Unisol HBS will be adapted to prepare an emulsion of PFC in Unisol (Unisol-PFC) and the perfusion parameters necessary to facilitate efficient perfusion will be determined using a LifePort(R) perfusion machine. The second aim will be to evaluate the efficacy of PFC-perfusion on the quality of post-perfusion isolation of islets. Using an established model of split-lobe perfusion the goal will be to compare the yield and quality of islets isolated from porcine pancreas lobes perfused with Unisol-PFC compared with Unisol alone. The anticipated outcome of this approach is that the implementation of PFC-augmented perfusion will provide a sustainable reservoir of O2 to meet the markedly reduced demands of the organ during extended cold ischemic storage. In turn, this will provide the means for high energy phosphate regeneration and avert the well recognized consequences of anaerobic glycolysis that the organ is forced to switch to during hypoxia and ischemia. While these studies are specifically designed to focus on the clinical need in islet transplantation, the underlying technology developments will be readily applicable to all transplantable organs. PUBLIC HEALTH RELEVANCE: Insulin-dependent diabetes is one of the major health problems worldwide and there is a great deal of interest in developing a potential cure by transplantation of islet cells isolated from a donor pancreas. A critical component of this approach is the availability of sufficient high quality islets to reverse diabetes in the patient. Current methods of storing organs prior to transplantation, or storing the pancreas prior to islet isolation, rely on hypothermic preservation modalities in which the organ still endures some injury from oxygen deprivation. This research is focused on the development of a new alternative technique to sustain oxygen delivery to the organ using perfusion technology with new inert oxygen-carrying solutions.