Evaluation of growth potential of ice-free vitrified heart valves in a pediatric porcine model.

摘要：这项多元化行政补充建议的重点是获得博士后支持 一位杰出的个人，Kamala Sundararaj博士，致力于我们的第一阶段STTR赠款，旨在翻译 儿科心脏瓣膜的无冰冷冻保存，并接受小企业创业培训。 儿童心脏瓣膜置换术是一个严重的问题，因为没有心脏瓣膜植入物生长。 和病人在一起。随着患者年龄的增长，目前使用的瓣膜需要更换 相关死亡率高(~40%)。为了满足这种临床需求，我们正在开创一种全新的 移植成长心脏瓣膜的方法，我们称之为部分心脏移植(PHT)。PHT 心脏移植与心脏移植不同，因为只有心脏中含有瓣膜的部分才会被移植。基座 根据我们在免疫抑制小猪身上的初步数据，我们最近进行了世界上第一个人类部分 2022年4月22日进行心脏移植，瓣膜发育良好。然而，供者部分心脏的机会 在正确的时间进行移植是不可能的。因此，我们建议发展一个网络 年在全国主要儿科心血管医学中心拥有技术许可证的组织库 为临床应用做好准备。我们的中心假设是玻璃化和纳米武装的PHTs可以满足这两种情况 生长期儿童原位移植后的血流动力学和生物学功能。在此阶段I 建议有三个具体目标：第一，提出优化短期保存协议。我们的 这一目标的工作假设是PHTs比完整的人能耐受更长的死后冷缺血时间 红心。采购和冷藏对仔猪来源的PHTs的影响将通过评估进行评估 在体外的生存能力。这将在解剖后确定PHT采购的预期地理范围 根据估计的冷藏旅行时间计算。在第二个具体目标中，我们将优化玻璃化冷冻方案 对于PHTs来说。我们关于这个目标的工作假设是，无冰冷冻保存采用组织玻璃化， 为成年猪肺瓣膜开发的快速纳米温控和细胞凋亡抑制技术可以进一步 针对儿科病例所需的较小的PHTs进行了优化。不同的冷冻保护剂加载时间、暴露时间 条件，并将通过评估在体外的生存能力来评估凋亡抑制药。这将确立 儿科PHTs玻璃化冷冻的最佳方案。在最终目标中，我们将评估移植后的生长情况 最佳玻璃化冷冻和纳米臂深低温保存的PHTs的存活率和血流动力学功能。我们的工作 这一目标的假设是，优化的方案将允许储存一个月的玻璃化PHTs 像新鲜的PHTs一样在体内发挥作用。在较早的AIMS中制定的优化协议将在 猪白细胞抗原与生长型免疫抑制仔猪PHT模型相匹配。这将是 建立PHT玻璃化冷冻、加温、封存的方法，为今后的临床应用奠定基础。在结束时 在这些目标中，预计Sundaraj博士将拥有必要的工具来确立自己作为 成功的独立调查员，并成为一名企业家。

Abstract: This diversity administrative supplement proposal is focused on obtaining postdoctoral support for an outstanding individual, Dr. Kamala Sundararaj, to work on our Phase I STTR grant directed at translation of ice-free cryopreservation of heart valves for pediatrics and be trained in small business entrepreneurship. Heart valve replacement in children is a serious problem because there are no heart valve implants that grow with the patient. The valves that are currently employed need to be changed as the patient grows with a very high associated mortality rate (~40%). In response to this clinical need, we are pioneering an entirely new approach to deliver growing heart valve implants, which we are calling partial heart transplantation (PHT). PHT differs from heart transplantation because only the part of the heart containing a valve is transplanted. Based on our preliminary data in immunosuppressed piglets, we recently performed the world’s first human partial heart transplant on 4/22/2022 with demonstrated valve growth. However, the chance of a donor partial heart transplant being available at just the right time is low. Therefore, we propose development of a network of tissue banks with technology licenses at major pediatric cardiovascular medical centers nationwide in preparation for clinical application. Our central hypothesis is that vitrified and nanowarmed PHTs can fulfill both their hemodynamic and biological functions after orthotopic transplantation in growing children. In this Phase I proposal there are three specific aims: First we propose optimization of short-term preservation protocols. Our working hypothesis for this aim is that PHTs will tolerate longer post-mortem cold ischemic times than intact hearts. The impact of procurement and refrigeration on piglet-derived PHTs will be evaluated by assessment of viability in vitro. This will establish the anticipated geographic range for PHT procurement after dissection based upon estimated refrigerated travel time. In the second specific aim we will optimize vitrification protocols for PHTs. Our working hypothesis for this aim is that ice-free cryo-preservation employing tissue vitrification, rapid nanowarming and apoptosis inhibition developed for adult porcine pulmonary heart valves can be further optimized for smaller PHTs required for pediatric cases. Different cryoprotectant loading times, exposure conditions, and apoptosis inhibitors will be evaluated by assessment of viability in vitro. This will establish the optimal vitrification protocol for pediatric PHTs. In the final aim we will evaluate post-transplant growth, leaflet viability and hemodynamic function of optimally vitrified and nanowarmed cryopreserved PHTs. Our working hypothesis for this aim is that optimized protocols will allow vitrified PHTs that were banked for one month to function in vivo like fresh PHTs. The optimized protocols developed in the earlier aims will be evaluated in a swine leukocyte antigen matched growing immunosuppressed piglet PHT model by transplantation. This will establish the PHT vitrification, warming, and banking methods for future clinical application. At the conclusion of these aims it is anticipated that Dr. Sundaraj will have the necessary tools to establish herself as a successful independent investigator and become an entrepreneur.