Ceria Nanoparticles that can Protect against Ischemic Stroke
Ceria Nanoparticles that can Protect against Ischemic Stroke
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DOI：
10.1002/anie.201203780
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发表时间：
2012-01-01
影响因子：
16.6
通讯作者：
Hyeon, Taeghwan
中科院分区：
文献类型：
--
作者：
Kim, Chi Kyung;Kim, Taeho;Hyeon, Taeghwan
缺血性中风是美国成人残疾的主要原因，也是全球第二大死亡原因。[1]在缺血期间产生并积累活性氧物质（ROS），例如超氧阴离子（O2 C12）、过氧化氢（H2 O2）和羟基自由基（HOC 12）。这些物种诱导氧化损伤，这是导致缺血性损伤的最关键机制之一，[2]并且氧化损伤促进中风相关的细胞死亡机制，例如细胞凋亡。[3]结果，神经元网络和神经血管单位被完全破坏，大脑功能停止。然而，没有有效的缺血性脑卒中的神经保护治疗已被开发用于临床实践。尽管抗氧化剂药物的可用性，没有治疗已被证明可以保护急性缺血性中风后的氧化损伤human.Ce2纳米粒子是已知的，通过可逆地结合氧和Ce 3+（还原）和Ce 4+（氧化）之间的转移在颗粒表面表现出自由基清除活性。[4]从二氧化铈纳米颗粒的晶体结构来看，铈离子大多以Ce 4+的价态存在;然而，粒径的减小导致颗粒表面出现氧空位，这使得Ce 3+得以共存。[5]此外，二氧化铈纳米颗粒的催化性能可以通过使用小于4 nm的超小纳米颗粒来进一步增强。[6]二氧化铈纳米颗粒在氧化态和自由基之间切换的能力与生物抗氧化剂相当。实际上是
Ischemic stroke is the leading cause of adult disability in the United States and the second leading cause of death worldwide.[1] Reactive oxygen species (ROS), such as the superoxide anion (O2CÀ), hydrogen peroxide (H2O2), and hydroxyl radical (HOCÀ), are generated and accumulate during ischemic periods. These species induce oxidative damage, which is one of the most critical mechanisms responsible for causing ischemic injury,[2] and oxidative damage elicits stroke-related cell death mechanisms, such as apoptosis.[3] As a result, neuronal networks and neurovascular units are completely destroyed, and the brain function is stopped. However, no effective neuroprotective therapy for ischemic stroke has been developed for clinical practice. Despite the availability of antioxidant drugs, no treatments have been proven to protect against oxidative damage after acute ischemic stroke in humans.Ceria nanoparticles are known to exhibit free radical scavenging activity by reversibly binding oxygen and shifting between the Ce3+(reduced) and Ce4+(oxidized) forms at the particle surface.[4] From the crystal structure of ceria nanoparticles, cerium ions mostly exist in the valence state of Ce4+; however, reduction in particle size results in oxygen vacancies from the particle surface, which allows the coexistence of Ce3+.[5] Moreover, the catalytic properties of ceria nanoparticles can be further enhanced by using ultrasmall nanoparticles of less than 4 nm.[6] The ability of ceria nanoparticles to switch between oxidation states and scavenge free radicals is comparable to biological antioxidants. In fact, it was