Vong Long Binh, Kobayashi Makoto, Nagasaki Yukio
Department of Materials Science, Graduate School of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8573, Japan.
Department of Molecular and Developmental Biology, Faculty of Medicine, University of Tsukuba , 1-1-1 Tennoudai, Tsukuba 305-8575, Japan.
Mol Pharm. 2016 Sep 6;13(9):3091-7. doi: 10.1021/acs.molpharmaceut.6b00225. Epub 2016 Jul 25.
Recently, we have been developing polymer and nanoparticle-based antioxidative nanotherapeutics. Our strategy is to eliminate overproduced reactive oxygen species (ROS), which are strongly related to various diseases. In order to facilitate the transition of the nanotherapeutics into clinical studies, we investigated the toxicity and antioxidant activity of our nanoparticles in a zebrafish model. In this study, zebrafish larvae were exposed to our highly ROS-scavenging nanoparticle (RNP(O)), which was prepared using our original amphiphilic block copolymer, methoxy-poly(ethylene glycol)-b-poly[4-(2,2,6,6-tetramethylpiperidine-1-oxyl)oxymethylstyrene] (MeO-PEG-b-PMOT). When the larvae were exposed to 10-30 mM of low-molecular-weight (LMW) nitroxide radical (4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl; TEMPOL), all were dead after 12 h, whereas no larva death was observed after exposure to RNP(O) at the same high concentrations. By staining mitochondria from the larvae, we found that LMW TEMPOL significantly induced mitochondrial dysfunction. In contrast, RNP(O) did not cause any significant reduction in the mitochondrial function of zebrafish larvae. It is important to reaffirm that RNP(O) treatment significantly enhanced survival of larvae treated with ROS inducers, confirming the antioxidant activity of RNP(O). Interestingly, RNP(O) exposure induced the expression of Nrf2 target gene (gstp1) in the larvae's intestines and livers. The results obtained in this study indicate that the antioxidative nanoparticle RNP(O) has great potential for clinical trials as it exhibits a potent therapeutic effect and extremely low toxicity to zebrafish embryos.
最近，我们一直在研发基于聚合物和纳米颗粒的抗氧化纳米疗法。我们的策略是清除过量产生的活性氧（ROS），而ROS与多种疾病密切相关。为了促进纳米疗法向临床研究的转化，我们在斑马鱼模型中研究了纳米颗粒的毒性和抗氧化活性。在本研究中，斑马鱼幼虫暴露于我们高度清除ROS的纳米颗粒（RNP(O)），该纳米颗粒是使用我们原创的两亲性嵌段共聚物甲氧基聚（乙二醇）-b-聚[4-(2,2,6,6-四甲基哌啶-1-氧基)氧甲基苯乙烯]（MeO-PEG-b-PMOT）制备的。当幼虫暴露于10-30 mM的低分子量（LMW）氮氧自由基（4-羟基-2,2,6,6-四甲基哌啶-1-氧基；TEMPOL）时，12小时后全部死亡，而在相同高浓度下暴露于RNP(O)后未观察到幼虫死亡。通过对幼虫的线粒体进行染色，我们发现LMW TEMPOL显著诱导线粒体功能障碍。相比之下，RNP(O)并未导致斑马鱼幼虫的线粒体功能有任何显著降低。必须再次强调的是，RNP(O)处理显著提高了用ROS诱导剂处理的幼虫的存活率，证实了RNP(O)的抗氧化活性。有趣的是，RNP(O)暴露诱导了幼虫肠道和肝脏中Nrf2靶基因（gstp1）的表达。本研究获得的结果表明，抗氧化纳米颗粒RNP(O)在临床试验中具有巨大潜力，因为它对斑马鱼胚胎表现出强大的治疗效果和极低的毒性。
