New Solutions to Improve Islet Recovery after Machine Preservation of Pancreas

描述（由申请人提供）：由于使用“埃德蒙顿方案”获得的结果，用于I型糖尿病临床治疗的胰岛移植重新引起人们的兴趣。然而，在这个时候，用于胰岛分离和移植的供体胰腺的采购还处于起步阶段。大多数在较远的供体部位的胰腺并没有获得，因为在运送到胰岛分离和移植中心的过程中，有理由担心死后缺血。灌注/保存技术已被证明对避免肾移植中的缺血性损伤具有重要影响。该提案旨在将这种方法应用于保存和获取用于移植的可行胰岛。该提案的主要目的是使用最先进的灌注技术和新的保存解决方案来测试机器灌注可以提高从缺血性胰腺制备的胰岛的产量和活力的假设。为此，在先前的研究中设计并构建了原型胰腺转运蛋白（PTR），该研究证明了使用猪模型在2-7 ℃下进行24小时灌注保存的可行性。这超过了16小时的记录是目前临床上安全的，静态冷藏供体胰腺的限制。在这里，我们提出了一个免费的研究，以解决第二个重要因素，进一步发展这项技术，即设计和优化的灌注液，以最大限度地提高产量和活力的孤立胰岛后，低温机灌注保存。更具体地说，在I期研究中，将比较新的专有溶液（Unisol）与当前标准器官保存溶液（KPS 1和UW Viaspan）对新鲜猪胰腺的24小时保存。这项新技术的安全性和有效性将在II期研究中进一步研究，其中用于灌注PTR中胰腺的溶液的设计将在四个特定目标中进行优化。第一步将是使用高通量测定系统来选择要掺入基础灌注液中的细胞保护添加剂。第二步将需要比较胰腺灌注液与添加细胞保护性鸡尾酒的胰腺灌注液，以机器保存无热缺血的新鲜胰腺。然后，将使用优化的灌注液评价冷灌注时间（24和48小时）和热缺血时间（长达60分钟）对猪胰岛分离参数的相互作用，以确定潜在的临床范围和技术限制。最后，不适合移植的人类胰腺将用于该技术的临床前验证。预计胰腺转运蛋白和胰腺灌注方案的可用性将允许利用大多数（如果不是全部）适合在美国移植的胰腺。此外，PTR可以允许胰岛分离库用于长期储存。银行将允许有时间更好地进行供体与受体的HLA配型，现成的可用性，并使质量保证/控制程序能够在移植前进行。这项研究计划得到了三个主要临床中心的合作支持，这些中心对验证这种灌注技术以供未来使用感兴趣。 项目叙述：胰岛素依赖型糖尿病是世界范围内的主要健康问题之一，现在人们对开发一种通过移植从供体胰腺分离的胰岛细胞来潜在治愈的选择非常感兴趣。这种方法的一个关键组成部分是提供足够的高质量胰岛来逆转患者的糖尿病。这项研究的重点是开发新技术（灌注机和保护性解决方案），以提高胰腺保存的质量，从而获得更多的高功能胰岛细胞。

DESCRIPTION (provided by applicant): Transplantation of islets of Langerhans for the clinical treatment of Type I diabetes has had a resurgence of interest due to results obtained using the "Edmonton protocol". However, at this time, procurement of donor pancreases for islet isolation and transplantation is in its infancy. Most pancreases at more remote donor sites are not procured due to justified concerns about post-mortem ischemia during transport to the islet isolation and transplant center. Perfusion/preservation technology has been shown to have a major impact in circumventing ischemic injury in kidney transplantation. This proposal seeks to apply this approach to the preservation and procurement of viable islets for transplantation. The primary objective of this proposal is to use state-of-the-art perfusion technology and new preservation solutions to test the hypothesis that machine perfusion can improve the yield and viability of islets prepared from ischemic pancreases. To this end, a prototype pancreas transporter (PTR) has been designed and constructed in a previous study that demonstrated the feasibility of 24h perfusion preservation at 2-7 degrees C using a porcine model. This exceeds the 16h documented to be the present clinical limits of safe, static cold storage of donor pancreata. Here we propose a complimentary study to address the second important factor for further development of this technology, namely the design and optimization of the perfusate to maximize the yield and viability of isolated islets after hypothermic machine perfusion preservation. More specifically, in the Phase I study a new proprietary solution (Unisol) will be compared with current standard organ preservation solutions (KPS1 and UW Viaspan) for 24h preservation of fresh porcine pancreata. The safety and efficacy of this new technology will be further investigated during a Phase II study in which the design of the solution used to perfuse the pancreas in the PTR will be optimized in four specific aims. The first step will be to use a system of high throughput assays to select cytoprotective additives to be incorporated into the base perfusates. The second step will entail a comparison of pancreas perfusates with the addition of the cytoprotective cocktail for machine preservation of fresh pancreata with no warm ischemia. Then the interaction between cold perfusion time (24 and 48h) and warm ischemia time (up to 60 min) on porcine islet isolation parameters will be evaluated using the optimized perfusate for the definition of the potential clinical scope and technology limits. Finally, human pancreases that are unsuitable for transplantation will be employed for pre-clinical validation of this technology. It is anticipated that the availability of a pancreas transporter and pancreas perfusion protocols will permit utilization of most, if not all, pancreases suitable for transplantation in the U.S. Furthermore, the PTR may permit islet isolation banking for long-term storage. Banking would allow time for better HLA matching of donors to recipients, off-the-shelf availability, and enable quality assurance/control procedures to be conducted prior to transplantation. This research program is supported by collaboration with three major clinical centers interested in validation of this perfusion technology for their future use. Project Narrative: Insulin-dependent diabetes is one of the major health problems worldwide and there is now a great deal of interest in developing an option for 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. This research is focused on the development of new technologies (a perfusion machine and protective solutions) for improving the quality of pancreas preservation to yield larger numbers of high functioning islet cells.