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.

摘要： 器官库有可能彻底改变器官用于移植的方式。复温 从玻璃化状态获得器官如肾脏是获得成功冷冻保存的关键步骤。这 将允许在移植前改进分配、运输和受体准备，同时 为其他工程组织的潜在供应链提供缺失的环节。典型的冷冻过程 通过冰晶形成和细胞脱水对生物材料造成显著损害。但随着 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“透明”）中。 “无定形”）或无冰状态，允许长期冷冻保存。我们的合作者和顾问博士。 格雷格·法希自20世纪80年代以来一直能够玻璃化兔子肾脏。然而，成功的复温， 玻璃化肾脏仍然是将玻璃化转化为器官库的挑战。具体地说， 达到避免偏差所需的临界升温速率（数十至数百oC/min）（即 在加热期间结晶）是不可能的。此外，以足够均匀的方式实现这些速率， 还需要整个器官的时尚，以避免可能使脆性材料破裂的热应力， 所以升温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的磁性纳米粒子的能力，或 “冷冻保存”，以克服这一主要限制，阻碍进一步发展的散装冷冻保存的 肾脏尽管已经尝试了电磁复温，但是波与组织的直接耦合将导致 固有地导致加热不均匀性，这导致结晶、开裂和不同的活性。在 低射频（RF < 1 MHz）交变磁场（AMF）可以均匀地穿透组织 而没有衰减和可忽略的介电耦合。虽然这些低频场将无法 快速加热组织本身，他们能够产生显着的加热通过耦合与 磁性（例如氧化铁）纳米颗粒。我们已经证明，这种方法可以产生 加热速率足够快，以避免大多数相关CPA中的偏差（高达200 oC/min），并且应 规模独立于样本量。 本研究的目的是改进这种新的冷冻技术用于冷冻保存肾脏 进行移植为此，在目标1中，我们将对CPA和纳米颗粒混合物进行物理表征， 兔子和大型哺乳动物的肾脏。在目标2中，我们将展示我们灌注该CPA的能力， 将纳米颗粒组合物植入兔肾中，玻璃化和冷冻，同时保持活力、细胞功能 和结构组织完整性。最后，在目标3中，我们将证明玻璃化冷冻后的体内功能， 兔肾移植和人肾刮除 总之，本提案的重点将是利用我们突破性的自动化技术， 优化CPA组合物和兔肾中的纳米颗粒递送，并证明原理工作以扩大规模 猪和人的肾脏用于最终的临床肾脏储存和移植。