Nanotoxicity assessment of quantum dots: from cellular to primate studies. Chem Soc Rev
School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore. .Chemical Society Reviews (Impact Factor: 33.38). 11/2012; 42(3). DOI: 10.1039/c2cs35392j
Tremendous research efforts have been devoted to fabricating high quality quantum dots (QDs) for applications in biology and medicine. Much of this research was pursued with an ultimate goal of using QDs in clinical applications. However, a great deal of concern has been voiced about the potential hazards of QDs due to their heavy-metal content. Many studies have demonstrated toxicity of various QDs in cell culture studies. However, in a smaller number of studies using small animal models (mice and rats), no abnormal behaviour or tissue damage was noticed over periods of months after the systemic administration of QDs. Nevertheless, the correlation of these results with the potential for negative effects of QD on humans remains unclear. Many urgent questions must be answered before the QDs community moves into the clinical research phase. This review provides an overview of the toxicity assessment of QDs, ranging from cell culture studies to animal models and discusses their findings. Guidelines for using various nonhuman primate models for QD toxicity studies are highlighted. This review article is intended to promote the awareness of current developments of QD applications in biology, the potential toxicity of QDs, and approaches to minimizing toxicity.
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- "Nowadays, the European Union is limiting the use of cadmium and other metals in plastics or coatings (European Chemicals Agency, 2013). In general, adult fishes or mammalian models such as mice or rats are usually employed to evaluate in vivo effects of contaminants, but these studies are time consuming, present ethical issues and are expensive (Yong et al., 2013). The use of zebrafish larvae appears as an alternative model, since it represents the dynamic that occur in vivo in a complex organism (Dai et al., 2014;Kim, 2013). "
ABSTRACT: The concern related to the use of nanomaterials is growing nowadays, especially the risk associated with their emission or exposure. One type of nanomaterials that has attracted much attention is quantum dots (QDs). QDs incorporation in consumer goods increases the probability of their entering in the environment and then into living organisms and human. In order to evaluate their potential to be bioconcentrated, zebrafish larvae have been exposed to SeCd/ZnS QDs, after performing an exhaustive characterization of these nanoparticles under the assay conditions. These data were compared with those obtained when zebrafish larvae were exposed to ionic cadmium. Finally, distribution of ionic Cd and QDs in exposed zebrafish larvae have been evaluated by Laser Ablation ICP-MS.
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- "Most of the developed theranostic agents, however, are still difficult to be translated into clinical applications. A significant concern is the potential toxicity of constituent materials (e.g., metal or semiconductor nanoparticles) 5, 6. Some agents also require specialized equipments, besides imaging instruments, to release therapeutic materials (e.g., magnetic hyperthermia, photodynamic therapy). "
ABSTRACT: Theranostic agents present a promising clinical approach for cancer detection and treatment. We herein introduce a microbubble and liposome complex (MB-Lipo) developed for ultrasound (US) imaging and activation. The MB-Lipo particles have a hybrid structure consisting of a MB complexed with multiple Lipos. The MB components are used to generate high echo signals in US imaging, while the Lipos serve as a versatile carrier of therapeutic materials. MB-Lipo allows high contrast US imaging of tumor sites. More importantly, the application of high acoustic pressure bursts MBs, which releases therapeutic Lipos and further enhances their intracellular delivery through sonoporation effect. Both imaging and drug release could thus be achieved by a single US modality, enabling in situ treatment guided by real-time imaging. The MB-Lipo system was applied to specifically deliver anti-cancer drug and genes to tumor cells, which showed enhanced therapeutic effect. We also demonstrate the clinical potential of MB-Lipo by imaging and treating tumor in vivo.
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- "Compared to traditional organic dyes and fluorescent proteins, QDs have some unique photophysical properties, for example, the broad/continuous excitation spectrum and narrow/symmetric emission spectrum, high photobleaching threshold, high emission quantum yield, and so on   . These advantages make QDs to be excellent probes for some chemical and biological assay   . Some metal ions, small molecules, and biomacromolecules could be detected by using QDs as fluorescent probe based on fluorescence quenching or fluorescence enhancement phenomenon       . "
ABSTRACT: In this contribution, a simple and sensitive fluorescent sensor for the determination of both the three ruthenium anticancer drugs (1 to 3) and calf thymus DNA (ctDNA) was established based on the CdTe quantum dots (QDs) fluorescence "OFF-ON" mode. Under the experimental conditions, the fluorescence of CdTe QDs can be effectively quenched by ruthenium anticancer drugs because of the surface binding of these drugs on CdTe QDs and the subsequent photoinduced electron transfer (PET) process from CdTe QDs to ruthenium anticancer drugs, which render the system into fluorescence "OFF" status. The system can then be "ON" after the addition of ctDNA which brought the restoration of CdTe QDs fluorescence intensity, since ruthenium anticancer drugs broke away from the surface of CdTe QDs and inserted into double helix structure of ctDNA. The fluorescence quenching effect of the CdTe QDs-ruthenium anticancer drugs systems was mainly concentration dependent, which could be used to detect three ruthenium anticancer drugs. The limits of detection were 5.5 × 10(-8) M for ruthenium anticancer drug 1, 7.0 × 10(-8) M for ruthenium anticancer drug 2, and 7.9× 10(-8) M for ruthenium anticancer drug 3, respectively. The relative restored fluorescence intensity was directly proportional to the concentration of ctDNA in the range of 1.0 × 10(-8) M ∼ 3.0 × 10(-7) M, with a correlation coefficient (R) of 0.9983 and a limit of detection of 1.1 × 10(-9) M. The relative standard deviation (RSD) for 1.5 × 10(-7) M ctDNA was 1.5% (n = 5). There was almost no interference to some common chemical compounds, nucleotides, amino acids, and proteins. The proposed method was applied to the determination of ctDNA in three synthetic samples with satisfactory results. The possible reaction mechanism of CdTe QDs fluorescence "OFF-ON" was further investigated. This simple and sensitive approach possessed some potential applications in the investigation of interaction between drug molecules and DNA.
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