Biocompatible fluorescence-enhanced ZrO 2 –CdTe quantum dot nanocomposite for in vitro cell imaging

School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, 637457 Singapore.
Nanotechnology (Impact Factor: 3.82). 04/2011; 22(15):155604. DOI: 10.1088/0957-4484/22/15/155604
Source: PubMed


With advances of quantum dots (QDs) in bioimaging applications, various materials have been used to coat QDs to reduce their nanotoxicity; however, the coating could introduce new toxic sources and quench the fluorescence in bioimaging applications. In this work, ZrO₂, an excellent ceramic material with low extinction coefficient and good biocompatibility, is utilized to coat CdTe QDs for the first time. Experimental results show that ZrO₂-QD nanocomposites with the size of ~30 nm possess enhanced fluorescence emission, lower nanotoxicity and gradually increased fluorescence under 350 nm light illumination. After functionalization with folic acid, they were applied to label cultured HeLa cells effectively. Therefore, the ZrO₂-QD nanocomposites could be promising biocompatible nanomaterials with strong fluorescence emission to replace or complement QDs in biomedical applications.

1 Follower
5 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: Quantum dots (QDs) hold great promise in many biological applications, with the persistence of safety concerns about the environment and human health. The present work investigated the potential toxicity of CdTe QDs on the function of mitochondria isolated from rat livers by examining mitochondrial respiration, swelling, and lipid peroxidation. We observed that QDs can significantly affect the mitochondrial membrane properties, bioenergetics and induce mitochondrial permeability transition (MPT). These results will help us learn more about QDs toxicity at subcellular (mitochondrial) level.
    Journal of hazardous materials 08/2011; 194:440-4. DOI:10.1016/j.jhazmat.2011.07.113 · 4.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We propose an ingenious method for synthesizing cross-linked hollow fluorescent carbon nanoparticles (HFCNs) with green emission by simply mixing acetic acid, water, and diphosphorus pentoxide. This is an automatic method without external heat treatment to rapidly produce large quantities of HFCNs, in contrast to other syntheses of fluorescent carbon nanoparticles that required high temperature, complicated operations, or long reaction times. Characterizations of HFCNs through high-resolution transmission electron microscopy, infrared/Raman spectroscopy, and X-ray diffraction indicate that abundant small oxygenous graphite domains existed and endowed the HFCNs with fluorescent properties. After simple post-treatments, the cross-linked HFCNs can be used for cell-imaging applications. Compared with traditional dyes and CdTe quantum dots, HFCNs are the superior fluorescent bioimaging agent according to their low toxicity, stability, and resistance to photobleaching. The HFCNs were also applied to watermark ink and fluorescent powder, showing their promising potentials for further wide usage.
    ACS Nano 12/2011; 6(1):400-9. DOI:10.1021/nn2046373 · 12.88 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: An efficient and biocompatible drug nanocarrier is essential for nanomedicines to realize their full therapeutic potential. Here, we investigate the loading of a selective and potent anticancer drug, β-lapachone (β-lap), on a magnetite nanoparticle-decorated reduced graphene oxide (Fe(3)O(4)/rGO) and the in vitro anticancer efficacy of β-lap loaded Fe(3)O(4)/rGO. Reduced graphene oxide (rGO) with magnetic functionality was prepared via electrostatic interaction between positively charged magnetite (Fe(3)O(4)) nanoparticles and negatively charged GO, followed by hydrazine reduction of GO to rGO. The prepared Fe(3)O(4)/rGO shows that Fe(3)O(4) makes the Fe(3)O(4)/rGO hybrid magnetically separable for easy handling during drug loading and release and the Fe(3)O(4)/rGO hybrid exhibits significantly higher loading capacity than that of Fe(3)O(4)/GO, suggesting that restoration of the graphene basal plane upon reduction of GO enhances the interaction between β-lap and rGO. Cellular uptake studies using fluorescently labeled Fe(3)O(4)/rGO verifies successful internalization of Fe(3)O(4)/rGO into the cytoplasm while rGO without hybridized Fe(3)O(4) has poor uptake performance. Furthermore, β-lap loaded Fe(3)O(4)/rGO shows remarkably high cytotoxicity toward MCF-7 breast cancer cells while the blank Fe(3)O(4)/rGO produces no cytotoxic effects. The cytotoxicity results suggest that Fe(3)O(4)/rGO is an efficient drug carrier for anticancer treatments. The fine-tuning of the chemical structures of graphene oxides by reduction chemistry may provide a universal route for controlled loading and release of drugs or biomolecules to construct advanced delivery vehicles.
    Molecular Pharmaceutics 03/2012; 9(3):615-21. DOI:10.1021/mp2005356 · 4.38 Impact Factor
Show more