Abstract：
The combined approach of ex situ normothermic machine perfusion (NMP) and nanotechnology represents a strategy to mitigate ischemia/reperfusion injury in liver transplantation (LT). We evaluated the uptake, distribution, and efficacy of antioxidant cerium oxide nanoparticles (nanoceria) during normothermic perfusion of discarded human livers. A total of 9 discarded human liver grafts were randomized in 2 groups and underwent 4 h of NMP: 5 grafts were treated with nanoceria conjugated with albumin (Alb-NC; 50 µg/ml) and compared with 4 untreated grafts. The intracellular uptake of nanoceria was analyzed by electron microscopy (EM) and inductively coupled plasma-mass spectrometry (ICP-MS). The antioxidant activity of Alb-NC was assayed in liver biopsies by glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) assay, telomere length, and 4977-bp common mitochondrial DNA deletion (mtDNA4977 deletion). The cytokine profile was evaluated in perfusate samples. EM and ICP-MS confirmed Alb-NC internalization, rescue of mitochondrial phenotype, decrease of lipid droplet peroxidation, and lipofuscin granules in the treated grafts. Alb-NC exerted an antioxidant activity by increasing GSH levels (percentage change: +94% ± 25%; p = 0.01), SOD (+17% ± 4%; p = 0.02), and CAT activity (51% ± 23%; p = 0.03), reducing the occurrence of mtDNA4977 deletion (-67.2% ± 11%; p = 0.03), but did not affect cytokine release. Alb-NC during ex situ perfusion decreased oxidative stress, upregulating graft antioxidant defense. They could be a tool to improve quality grafts during NMP and represent an antioxidant strategy aimed at protecting the graft against reperfusion injury during LT.
摘要：
非原位常温机器灌注（NMP）和纳米技术的组合方法代表了减轻肝移植（LT）中缺血/再灌注损伤的策略。我们评估了吸收，分布，抗氧化剂氧化铈纳米颗粒（纳米氧化铈）在废弃人肝脏的正常体温灌注过程中的功效。总共9个丢弃的人肝移植物被随机分为2组，并接受4小时的NMP：5个移植物用与白蛋白（Alb-NC;50µg/ml）结合的纳米二氧化硅处理，并与4个未处理的移植物进行比较。通过电子显微镜（EM）和电感耦合等离子体质谱法（ICP-MS）分析了纳米二氧化铈的细胞内摄取。通过谷胱甘肽（GSH）在肝活检中测定Alb-NC的抗氧化活性，超氧化物歧化酶(SOD)和过氧化氢酶(CAT)测定,端粒长度,和4977-bp常见线粒体DNA缺失(mtDNA4977缺失)。在灌注液样品中评估细胞因子谱。EM和ICP-MS证实Alb-NC内化，拯救线粒体表型，减少脂滴过氧化，和脂褐素颗粒在处理的移植物中。Alb-NC通过增加GSH水平发挥抗氧化活性（百分比变化：94％±25％；p=0.01），SOD（+17%±4%；p=0.02），和CAT活性（51％±23％；p=0.03），减少mtDNA4977缺失的发生（-67.2%±11%；p=0.03），但不影响细胞因子的释放。Alb-NC在非原位灌注过程中降低了氧化应激，上调接枝抗氧化剂防御。它们可能是改善NMP期间移植物质量的工具，并代表了一种抗氧化策略，旨在保护移植物免受LT期间的再灌注损伤。
