Measuring and monitoring carbon nanotubes and their potential toxicity

描述(申请人提供)：美国环境保护署(EPA)最近将碳纳米管(CNTs)归类为一种新的化学物质。因此，碳纳米管现在受到监管控制，要求控制库存，量化碳纳米管数量，并可能进行毒性测试。然而，快速和廉价地量化商业可获得的材料中的碳纳米管并在标准条件下评估潜在的毒性是具有技术挑战性的任务。这里提出的研究利用了一种快速量化纳克量的碳纳米管的方法和评估可能的碳纳米管毒性的标准方案。这些方法将被用来开发一个将商业上可获得的碳纳米管类型的性质和毒性联系起来的数据库，该数据库将验证快速量化碳纳米管数量和毒性的方法的广泛适用性。一旦开发完成，该数据库将促进开展一项服务业务，以量化CNT制造商、进口商、消费者以及健康和安全人员的CNT数量和毒性。我们开发了一种利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法(SDS-PAGE)对液体样品中的少量碳纳米管进行定量的方法。一旦样品中碳纳米管的重量百分比已知，并制备了标准曲线，该方法提供了一种无标记且廉价的方法来定量纳米克碳纳米管。关于碳纳米管的毒性，文献中有相互矛盾的报道。达成协议不佳的主要原因有三个。首先，许多碳纳米管制剂受到有毒金属的污染，这些金属是制造碳纳米管的催化剂，例如铁，这些污染物在许多碳纳米管毒性研究中没有被去除。其次，毒性可能取决于碳纳米管的形式，并且可以随碳纳米管的共价或非共价官能化类型的不同而变化。第三，已经使用了各种各样的分析方法来评估毒性，包括一些已知碳纳米管通过与作为毒性报告的荧光有机化合物结合而干扰分析的情况。我们已经制定了标准协议来解决这三个问题。当第一阶段的任务完成后，第二阶段的提案将侧重于将该技术转化为服务企业，以量化和衡量碳纳米管的毒性。我们相信，随着对碳纳米管的监管要求继续发展，这将是对碳纳米管制造商、进口商、销售商、消费者和健康与安全医疗界的一项有价值的服务。 与公共卫生相关：纳米材料的使用正变得越来越广泛。特别是，碳纳米管使从药物输送到植入性设备再到生物传感器的新应用成为可能。随着这类材料的生产和使用的增加，必须建立对潜在毒性的彻底标准化表征和评估。

DESCRIPTION (provided by applicant): The Environmental Protection Agency (EPA) recently classified carbon nanotubes (CNTs) as a new chemical substance. Consequently, CNTs are now subject to regulatory controls that require inventory control, quantification of CNT amounts, and possibly toxicity tests. However, rapidly and inexpensively quantifying the CNTs in commercially available material and assessing potential toxicity under standard conditions, are technically challenging tasks. The research proposed here exploits a rapid method for quantifying nanogram amounts of CNTs and standard protocol for assessing possible CNT toxicity. These methods will be used to develop a database correlating properties and toxicity of commercially available CNT types that will validate the wide-spread applicability of a rapid approach to quantifying CNT amounts and toxicity. Once developed, the database will facilitate launching a service business to quantify CNT amounts and toxicity for CNT manufacturers, importers, consumers, and health & safety personnel. We have developed a method that uses sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS- PAGE) for quantifying small amounts of CNTs in liquid samples. Once the weight % of CNTs in a sample is known, and a standard curve has been prepared, the method provides a label-free and inexpensive way to quantify nanogram amounts of CNTs. There are conflicting reports in the literature on the toxicity of CNTs. There are three main reasons for the poor agreement. First, many CNT preparations are contaminated with toxic metals that are catalysts used in making CNTs, such as iron, and these contaminants were not removed in many CNT toxicity studies. Second, toxicity may depend on the form of the CNTs and can vary with different types of covalent or non-covalent functionalization of the CNTs. Third, a wide variety of assays have been used to assess toxicity, including some where CNTs are now known to interfere with the assay by binding to fluorescent organic compounds that are reporters of toxicity. We have developed standard protocols to address each of these three issues. When the tasks in phase I are completed, a phase II proposal will focus on translating the technology to a service business for quantifying and measuring the toxicity of CNTs. We believe this will be a valuable service to CNT manufacturers, importers, sellers, consumers, and the health & safety medical community as the regulatory demands on CNTs continue to develop. PUBLIC HEALTH RELEVANCE: The use of nanomaterials is becoming more widespread. In particular, carbon nanotubes are enabling novel applications from drug delivery to implantable devices to biosensors. As the production and use of such materials grows, it will be imperative that thorough standardized characterization and evaluation of potential toxicity be established.