纳米CeO_2在生物医药上的应用

Applications of Nanoceria in Biomedical Field

纳米CeO_2由于自身的结构特点,Ce^(4+)和Ce^(3+)在纳米粒子上共存,遇到氧化剂ROS,Ce^(3+)被氧化成Ce^(4+),因此它是一种还原剂。当周围环境改变时,它又有再生能力,从Ce^(4+)再生为Ce^(3+),这也是CeO_2的本质(有氧空穴)所决定的。这个性质使纳米CeO_2在生物医药上有很多应用,可以模拟SOD,CAT催化活性清除超氧阴离子自由基、过氧化氢分子、羟基自由基等对人体有害的ROS。有重点地例举了纳米CeO_2在癌症放疗中作为辅助剂的应用,对神经细胞的保护,防止过早蜕化,特别是对视网膜的保护。简述了纳米CeO_2的制备进展,更有效的和更长效的纳米CeO_2的研制进展。

Nanoceria in virtue of its character of structure,Ce^4＋ and Ce^3＋ are coexisting in the nanoparticles of ceria. Once oxidants such as ROS is close to nanoceria and reaction is happening,which makes Ce^3＋ to be changed into Ce^4＋ . While the condition is to be changed,it has opportunity of regeneration of Ce^3＋ from Ce^4＋ . This is the nature of nanoceria due to some of oxygen vacancies in it,which confer lots of applications in the biomedical field.They have SOD mimetic activity,scavenging superoxide anion radicals; CAT mimetic activity,scavenging hydrogen peroxide（ H2O2） and scavenging hydroxyl radicals（ OH·） etc. ROS are all harmful for human being,unless it is in lower enough concentration. In this paper,several respects are concerned the applications of nanoceria,such as in treatment of cancer by radiation therapy as an assist agent,neuroprotection,especially in the protection of the retina and slow down the degeneration etc. The progress of nanoceria syntheses is present,some of them are more effective,while the others could be used. Final a discussion including some of important ideal is present.