INVESTIGATING TOXICOLOGY OF THIOL-CAPPED QUANTUM DOTS OF CADMIUM AND LEAD

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 进行研究以阐明巯基封端的CdSe、CdS、PbSe和PbS量子点（QD）在体内的毒理学和药代动力学。 量子点具有明亮的、光稳定的和尺寸可调的荧光，因此，它们作为用于生物医学成像和诊断的光可调探针受到广泛的研究。然而，由于未知的健康影响和毒性，将这些纳米材料用于人类引起了人们的担忧，了解这些颗粒在生物系统中的药代动力学行为需要分析和毒理学测试方法。在这个项目中，我们已经检查了镉，铅和硒对加热过程中的几个生物样品的溶解纳米粒子的准确定量的稳定性。结果表明，除非将溶解的样品加热至干燥，否则所有这些元素都是稳定的，允许可靠的测定而没有任何显著损失。所开发的方法有利于测量暴露动物器官中的总QD水平。为了鉴定离子金属和完整的量子点，设计了氢化物发生方法。优化了实验条件，选择性地测定了量子点在体内分解产生的镉、铅和硒离子。氢化物发生的使用将阐明量子点的生物稳定性。在另一项研究中，通过超声处理CdSe QD的溶液来研究CdSe QD的物理稳定性。结果发现，超声处理不引起任何崩解的CdSe量子点，无论颗粒大小。这一结果是重要的，因为它提供了一种提取金属离子而不改变器官中纳米颗粒组成的潜在工具。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Research is performed to elucidate toxicology and pharmacokinetics of thiol-capped CdSe, CdS, PbSe and PbS quantum dots (QDs) in vivo. QDs exhibit bright, photo-stable and size-tunable fluorescence and therefore, they are under extensive investigation as photo-tunable probes for biomedical imaging and diagnostics. However, the use of these nanomaterials on humans raises concerns due to the unknown health effects and toxicity, Understanding the pharmacokinetic behavior of these particles in biological systems requires both analytical and toxicology testing methods. In this project, we have examined the stability of Cd, Pb and Se against heating during dissolution of several biological samples for accurate quantification of nanoparticles. It was found that all there elements were stable to allow reliable determination without any significant losses unless dissolved samples are heated to dryness. The method developed is advantageous for measurement of total QD levels from organs of exposed animals. In an attempt to identify ionic metal and intact QDs, a hydride generation method was designed. Experimental conditions were optimized for selective measurement of ionic Cd, Pb and Se resulting from in vivo disintegration of the QDs in body. The use of hydride generation will elucidate the biological stability of the QDs. In another study, physical stability of the CdSe QDs was investigated by sonicating the solutions of CdSe QDs. It was found that sonication did not cause any disintegration on CdSe QDs regardless of particle size. This result is important as it affords a potential tool for extracting metal ions without altering the nanoparticle composition in the organs.