Organ banking for transplant—kidney cryopreservation by vitrification and novel nanowarming technology

通过玻璃化和新型纳米加温技术进行移植肾冷冻保存的器官库

• 批准号: 9912760
• 负责人: JOHN C BISCHOF
• 金额: $ 58.45万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-13 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9912760
• 关键词: Animal Model; Arteries; Biocompatible Materials; Blood Vessels; Cell Survival; Cell physiology; Cellular Structures; Clinical; Convection; Cost Savings; Coupling; Cryopreservation; Cryoprotective Agents; Crystal Formation; Crystallization; Data; Degenerative Disorder; Dehydration; Development; Dialysis procedure; Electromagnetics; Ensure; Family suidae; Freezing; Frequencies; Glass; Goals; Health Care Costs; Heart; Heart Valves; Heating; Human; Ice; Kidney; Kidney Transplantation; Life; Life Expectancy; Link; Liquid substance; Magnetic nanoparticles; Magnetism; Methods; Modeling; Nitrogen; Organ; Organ Size; Organ Transplantation; Oryctolagus cuniculus; Outcome; Patients; Perfusion; Polyethylene Glycols; Preparation; Prevention; Process; Property; Quality of life; Rewarming; Risk; Sample Size; Sampling; Savings; Silicon Dioxide; Speed; Stabilizing Agents; Structure; System; Techniques; Technology; Temperature; Testing; Time; Tissue Engineering; Tissue Viability; Tissues; Translations; Transplantation; Work; attenuation; biomaterial compatibility; biophysical properties; clinical translation; cold temperature; cryogenics; improved; in vivo; interest; iron oxide nanoparticle; kidney preservation; kidney vascular structure; magnetic field; nanoparticle; nanoparticle delivery; nanowarming; new technology; novel; preservation; prevent; programs; radio frequency; scale up; thermal stress; transplant model; vitreous state

ABSTRACT: Organ banking has the potential to revolutionize the way organs are used for transplantation. Rewarming organs such as kidneys from the vitrified state is a critical step in obtaining successful cryopreservation. This would allow improved allocation, transport, and recipient preparation prior to transplant, while simultaneously providing a missing link in the potential supply chain for other engineered tissues. Typical freezing processes cause significant damage to biomaterials through ice crystal formation and cellular dehydration. However, with the aid of cryoprotectant (CPA) solutions, biospecimens can be stabilized in the vitreous (i.e. “glass” or “amorphous”) or ice free state, allowing for long-term cryopreservation. Our collaborator and consultant Dr. Greg Fahy has been able to vitrify rabbit kidneys since the 1980s. However, successful rewarming of these vitrified kidneys has remained a challenge to translation of vitirification for organ banking. Specifically, achieving critical warming rates (tens to hundreds of oC/min) necessary to avoid devitirification (i.e. crystallization) during warming has not been possible. In addition, achieving these rates in a sufficiently uniform fashion throughout the organ is also required to avoid thermal stresses that can crack the brittle material, and so both speed and uniformity of warming are of critical importance. Here we propose to investigate the ability of radiofrequency heated magnetic nanoparticles, or “nanowarming,” to overcome this major limitation hindering further development of bulk cryopreservation of kidneys. Although electromagnetic rewarming has been tried, the direct coupling of the waves to tissue will inherently result in non-uniformity in heating, which leads to crystallization, cracking and differential viability. At lower radiofrequencies (RF < 1 MHz) alternating magnetic fields (AMFs) can uniformly penetrate tissues without attenuation and negligible dielectric coupling. Although these lower frequency fields will be unable to rapidly heat the tissue on their own, they are able to produce significant heating through coupling with magnetic (e.g. iron-oxide) nanoparticles. We have already demonstrated that this approach can generate heating rates rapid enough to avoid devitirification in most CPAs of interest (up to 200 oC/min) and should scale independent of sample size. The objective of this study is to refine this novel nanowarming technology for use in cryopreserving kidneys for transplant. To this end, in Aim 1 we will physically characterize CPA and nanoparticle mixtures to heat rabbit and larger mammalian kidneys. In Aim 2 we will demonstrate our ability to perfuse this CPA and nanoparticle combination into rabbit kidneys, vitrify and nanowarm while maintaining viability, cellular function and structural tissue integrity. Finally, in Aim 3 we will demonstate in vivo function after vitrification and nanowarming by transplant in rabbits and scaling for use in human kidneys In summary, the focus of this proposal will be to leverage our breakthrough nanowarming technology by optimizing CPA composition and nanoparticle delivery in rabbit kidneys with proof of principle work to scale up to porcine and human kidneys for eventual clinical kidney banking and transplantation.

抽象的： 器官库有可能彻底改变器官移植的方式。 将肾脏等器官置于玻璃化状态是获得成功冷冻保存的关键一步。 将允许改善移植前的分配、运输和受体准备，同时 为其他工程组织的潜在供应链提供了缺失的环节。 然而，通过冰晶形成和细胞脱水对生物材料造成重大损害。 在冷冻保护剂 (CPA) 溶液的帮助下，生物样本可以稳定在玻璃体（即“玻璃”或 “无定形”）或无冰状态，允许长期冷冻保存。 自 20 世纪 80 年代以来，Greg Fahy 就能够对兔子肾脏进行玻璃化冷冻，但成功地对其进行了复温。 玻璃化肾脏仍然是玻璃化器官库转化的一个挑战。 达到避免失透所必需的临界升温速率（数十至数百摄氏度/分钟）（即。 此外，以足够均匀的方式实现这些速率是不可能的。 整个器官的时尚也需要避免可能使脆性材料破裂的热应力，并且 因此变暖的速度和均匀性都至关重要。 在这里，我们建议研究射频加热磁性纳米颗粒的能力，或者 “纳米变暖”，以克服阻碍批量冷冻保存进一步发展的主要限制 尽管已经尝试过电磁复温，但波与组织的直接耦合将无法实现。 本质上会导致加热不均匀，从而导致结晶、破裂和活力差异。 较低的射频 (RF < 1 MHz) 交变磁场 (AMF) 可以均匀地穿透组织 尽管这些较低频率的场将无法在没有衰减和可忽略不计的介电耦合的情况下实现。 它们能够自行快速加热组织，通过与 我们已经证明这种方法可以生成磁性（例如氧化铁）纳米颗粒。 加热速率足够快，以避免大多数感兴趣的 CPA 失透（高达 200 oC/min），并且应该 规模与样本大小无关。 本研究的目的是完善这种新颖的纳米加热技术，用于冷冻保存肾脏 为此，在目标 1 中，我们将对 CPA 和纳米粒子混合物进行物理表征以进行加热。 在目标 2 中，我们将展示我们灌注这种 CPA 和的能力。 将纳米颗粒组合到兔肾中，进行玻璃化和纳米加热，同时保持活力和细胞功能 最后，在目标 3 中，我们将展示玻璃化和组织后的体内功能。 通过兔子移植实现纳米变暖以及用于人类肾脏的缩放 总之，该提案的重点是通过以下方式利用我们突破性的纳米变暖技术： 优化 CPA 成分和纳米颗粒在兔肾中的递送，并通过原理工作证明扩大规模 猪和人的肾脏用于最终的临床肾库和移植。