Investigations and Mitigation of Carbon Nanomaterial Toxicity

描述(申请人提供)：随着碳纳米管(CNT)的应用变得更加丰富，生产需求也越来越大。由于这种活性的增加，人们在检测碳纳米管的毒性方面进行了大量的研究。已发现纳米管对人体具有毒性作用，包括炎症、氧化应激和细胞凋亡，与石棉相似。因此，需要开发一种有效的方法来从环境中去除这些有毒纤维。我们在这里假设，通过使用酶催化，我们可以在环境和生理相关的环境中启动碳纳米管的降解。我们的初步数据显示，一种天然的辣根过氧化物酶(HRP)，加上低浓度的局部过氧化氢(40.5M)，可以降解这些纳米材料。我们还观察到人类髓过氧化物酶(HMPO)可以降解碳纳米管，说明了一种双管齐下的方法(环境和人类健康)。本项目的具体目标包括：(1)利用HRP和HMPO确定影响碳纳米管降解动力学的环境和结构因素；(2)确定HRP和HMPO催化碳纳米管降解的分子机理(S)；(3)测定HRP/HMPO降解碳纳米管的产物并评价其毒性。这项研究的重要终点将是了解碳纳米管及其转化产物对人类健康的影响，包括其在环境和体内生物降解所需的化学功能化。 与公共健康相关：纳米技术的发展极大地增加了碳纳米管的需求和使用，相应地，碳纳米管对健康的危害和对环境的毒性也相应增加。这就决定了开发从环境中安全移除碳纳米管的方法的必要性。这项提案概述了通过酶催化生物降解碳纳米管的新技术和协议，以减轻碳纳米材料对环境和随后的生理毒性。

DESCRIPTION (provided by applicant): As carbon nanotube (CNT) applications become more abundant, so do production demands. Because of this increased activity, much research has been performed in examining the toxicity of CNTs. Nanotubes have been found to exhibit toxic effects to the body including inflammation, oxidative stress, and apoptosis, similar to that witnessed from asbestos. As such, an effective method to remove these toxic fibers from the environment needs to be developed. We hypothesize here that by using enzymatic catalysis, we can initiate degradation of CNTs in environmentally and physiologically relevant settings. Our preliminary data shows that a natural enzyme horseradish peroxidase (HRP), along with low, local concentrations of H2O2 (40 5M), can degrade these nanomaterials. We have also observed that human myeloperoxidase (hMPO) can degrade CNTs, illustrating a two-pronged approach (environment and human health). Our specific goals for this project include (1) identifying environmental and structural factors affecting the kinetics of CNT degradation using HRP and hMPO, (2) identifying the molecular mechanism(s) of CNT degradation catalyzed by HRP and hMPO, (3) determining the products of HRP/hMPO- degradation of CNTs and evaluating their toxicity. The significant endpoint of this study will be marked by an understanding of the effects of CNTs and their transformation products on human health, including the necessary chemical functionalization for their biodegradation in the environment and in vivo. PUBLIC HEALTH RELEVANCE: Developments in nanotechnology vastly increase the demand and use of carbon nanotubes, correspondingly with their health hazards and toxicity to the environment. This dictates the necessity to develop approaches for safe removal of carbon nanotubes from the environment. This proposal outlines novel technologies and protocols for biodegradation of carbon nanotubes through enzymatic catalysis mitigating environmental and subsequent physiological toxicity from carbon nanomaterials.