BACKGROUND Ototoxicity is one of the major side effects of platinum-based chemotherapy, especially cisplatin therapy. To date, no FDA approved agents to alleviate or prevent this ototoxicity are available. However, ototoxicity is generally believed to be produced by excessive generation of reactive oxygen species (ROS) in the inner ear, thus leading to the development of various antioxidants, which act as otoprotective agents. Astaxanthin (ATX) is an interesting candidate in the development of new therapies for preventing and treating oxidative stress-related pathologies, owing to its unique antioxidant capacity. METHODS AND RESULTS In this study, we aimed to evaluate the potential antioxidant properties of ATX in the inner ear by using the HEI-OC1 cell line, zebrafish, and guinea pigs. Because ATX has poor solubility and cannot pass through round window membranes (RWM), we established lipid-polymer hybrid nanoparticles (LPN) for loading ATX. The LPN enabled ATX to penetrate RWM and maintain concentrations in the perilymph in the inner ear for 24 h after a single injection. ATX-LPN were found to have favorable biocompatibility and to strongly affect cisplatin-induced generation of ROS, on the basis of DCFHDA staining in HEI-OC1 cells. JC-1 and MitoTracker Green staining suggested that ATX-LPN successfully reversed the decrease in mitochondrial membrane potential induced by cisplatin in vitro and rescued cells from early stages of apoptosis, as demonstrated by FACS stained with Annexin V-FITC/PI. Moreover, ATX-LPN successfully attenuated OHC losses in cultured organ of Corti and animal models (zebrafish and guinea pigs) in vivo. In investigating the protective mechanism of ATX-LPN, we found that ATX-LPN decreased the expression of pro-apoptotic proteins (caspase 3/9 and cytochrome-c) and increased expression of the anti-apoptotic protein Bcl-2. In addition, the activation of JNK induced by CDDP was up-regulated and then decreased after the administration of ATX-LPN, while P38 stayed unchanged. CONCLUSIONS To best of our knowledge, this is first study concluded that ATX-LPN as a new therapeutic agent for the prevention of cisplatin-induced ototoxicity.

中文翻译：

---

虾青素负载的聚合物-脂质杂化纳米颗粒（ATX-LPN）：潜在的耳保护作用的评估。

背景技术耳毒性是基于铂的化学疗法，尤其是顺铂疗法的主要副作用之一。迄今为止，尚无FDA批准的减轻或预防这种耳毒性的药物。然而，通常认为耳毒性是由内耳中过量产生的活性氧（ROS）产生的，因此导致了各种作为耳保护剂的抗氧化剂的发展。由于其独特的抗氧化能力，虾青素（ATX）在预防和治疗氧化应激相关疾病的新疗法的开发中是一个有趣的候选者。方法和结果在这项研究中，我们旨在通过使用HEI-OC1细胞系，斑马鱼和豚鼠来评估内耳中ATX的潜在抗氧化特性。由于ATX的溶解性差且无法通过圆窗膜（RWM），因此我们建立了脂-聚合物杂化纳米颗粒（LPN）来装载ATX。LPN使ATX可以穿透RWM，并在单次注射后24小时内保持内耳的淋巴中的浓度。根据HEI-OC1细胞中DCFHDA染色，发现ATX-LPN具有良好的生物相容性，并强烈影响顺铂诱导的ROS生成。JC-1和MitoTracker Green染色提示ATX-LPN成功逆转了顺铂体外诱导的线粒体膜电位的降低，并从凋亡的早期阶段拯救了细胞，如用Annexin V-FITC / PI染色的FACS所证明的。此外，ATX-LPN在体内成功减轻了Corti和动物模型（斑马鱼和豚鼠）的培养器官中OHC的损失。在研究ATX-LPN的保护机制时，我们发现ATX-LPN降低了促凋亡蛋白（胱天蛋白酶3/9和细胞色素c）的表达，并增加了抗凋亡蛋白Bcl-2的表达。此外，ATX-LPN给药后，CDDP诱导的JNK激活被上调，然后降低，而P38保持不变。结论据我们所知，这是第一项研究得出的结论是ATX-LPN作为预防顺铂引起的耳毒性的新治疗剂。ATX-LPN给药后，CDDP诱导的JNK的激活上调，然后降低，而P38保持不变。结论据我们所知，这是第一项研究得出的结论是ATX-LPN作为预防顺铂引起的耳毒性的新治疗剂。ATX-LPN给药后，CDDP诱导的JNK的激活上调，然后下降，而P38保持不变。结论据我们所知，这是第一项研究得出的结论是ATX-LPN作为预防顺铂引起的耳毒性的新治疗剂。