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”取得的结果，移植朗格汉斯胰岛用于I型糖尿病的临床治疗重新引起了人们的兴趣。然而，目前用于胰岛分离和移植的供体胰腺的获取还处于起步阶段。由于在运送到胰岛隔离和移植中心的过程中存在死后缺血的合理担忧，大多数较偏远供体部位的胰腺不会被获取。灌流/保存技术已被证明在绕过肾移植中的缺血损伤方面有重要作用。这项建议旨在将这一方法应用于保存和采购可供移植的可行胰岛。这项建议的主要目的是使用最先进的灌流技术和新的保存方案来验证机器灌流可以提高从缺血胰腺制备的胰岛的产量和活力的假说。为此，在先前的一项研究中已经设计和构建了一个原型胰腺转运体(PTR)，该研究利用猪模型证明了在2-7℃下24小时灌流保存的可行性。这超过了目前文献记载的供体胰腺安全、静态冷藏的16h临床限度。在这里，我们建议进行一项补充研究，以解决该技术进一步发展的第二个重要因素，即设计和优化灌流液，以最大限度地提高低温机器灌流保存后孤立胰岛的产量和活力。更具体地说，在第一阶段研究中，一种新的专利溶液(Unisol)将与当前标准器官保存溶液(KPS1和UW Viaspan)进行比较，以保存新鲜猪胰腺24小时。这项新技术的安全性和有效性将在第二阶段研究中进一步研究，在该研究中，用于PTR中胰腺灌流的溶液的设计将根据四个具体目标进行优化。第一步是使用高通量检测系统来选择细胞保护性添加剂加入到基础灌流液中。第二步将需要比较胰腺灌注液和添加细胞保护性鸡尾酒对机器保存没有热缺血的新鲜胰腺的影响。然后使用优化的灌流液评估冷灌流时间(24小时和48小时)和热缺血时间(长达60分钟)对猪胰岛分离参数的影响，以确定潜在的临床范围和技术限制。最后，不适合移植的人胰腺将被用于这项技术的临床前验证。预计胰腺转运体和胰腺灌注方案的可获得性将允许使用大多数(如果不是全部)适合在美国移植的胰腺。此外，PTR可能允许胰岛隔离库用于长期存储。银行业务将使捐赠者和受赠者有更好的人类白细胞抗原配型、现成的可获得性，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与三个主要临床中心的合作支持，这些中心对验证这项灌注技术的未来用途感兴趣。 项目简介：胰岛素依赖型糖尿病是世界范围内的主要健康问题之一，目前人们对开发一种通过移植从捐赠者胰腺分离的胰岛细胞来潜在治愈的选择非常感兴趣。这一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。本研究的重点是开发新的技术(灌注机和保护液)，以提高胰腺保存的质量，以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.