ABSTRACT
INTRODUCTION: Concerns have been raised regarding occupational exposure to engineered nanomaterials (ENMs). Potential impacts on lung function from inhalation exposures are of concern as the lung is a sensitive ENM target in animals. Epidemiological data suggest that occupational exposure to ENMs may impact respiratory and cardiovascular health. Quantum dots (QDs) are ENMs with outstanding semiconductor and fluorescent properties with uses in biomedicine and electronics. QDs are known to induce inflammation and cytotoxicity in rodents and high dose exposures impact lung function 2 weeks after exposure. However, effects of mouse strain and the temporality of QD effects on lung function at more occupationally relevant doses have not been well-established. OBJECTIVE: We evaluated the impact of QD exposure on respiratory mechanics in C57BL/6J and A/J mice. Previous work found a greater initial inflammatory response to QD exposure in A/J mice compared to C57BL/6J mice. Thus, we hypothesized that A/J mice would be more sensitive to QD-induced effects on lung mechanics. METHODS: C57BL/6J and A/J mice were exposed to 6 µg/kg Cd equivalents of amphiphilic polymer-coated Cd/Se core, ZnS shell QDs via oropharyngeal aspiration. Lung mechanics were measured using forced oscillation, and inflammation was characterized by neutrophils and cytokines in bronchoalveolar lavage fluid. RESULTS: Both strains showed signs of QD-induced acute lung inflammation. However, lung mechanics were impacted by QD exposure in A/J mice only. CONCLUSIONS: Our findings suggest that susceptibility to QDs and similar ENM-induced changes in lung function may depend at least in part on genetic background.
Subject(s)
Inhalation Exposure/adverse effects , Lung/drug effects , Quantum Dots/toxicity , Respiratory Mechanics , Animals , Bronchoalveolar Lavage Fluid , Cadmium Compounds/toxicity , Cytokines , Inflammation , Lung/physiopathology , Mice , Mice, Inbred A , Mice, Inbred C57BL , Neutrophils , Selenium Compounds/toxicity , Time FactorsABSTRACT
Engineering plasmonic nanostructures that simultaneously achieve high colloidal stability, high photothermal stability, low non-specific binding to biological specimens, and low toxicity is of significant interest to research in bionanotechnology. Using gold nanorods, we solved this problem by encapsulating them with a multilayer structure, silica, hydrophobic ligands, and amphiphilic-polymers. In comparison with nanorods covered with the conventional surface chemistries, such as surfactants, polyelectrolytes, thiolated polymers, and silica shells alone, the new nanorods remain single in various solutions and show remarkable stability against laser irradiation. We further demonstrated specific targeting and effective treatment of prostate tumor cells using nanorod-aptamer bioconjugates. This exquisitely formulated nanoencapsulation technology could potentially help stabilize other plasmonic nanostructures that are not in the most thermodynamically or chemically stable states, and should open exciting opportunities in nanotechnology-based imaging and therapeutics.
Subject(s)
Aptamers, Nucleotide/administration & dosage , Drug Carriers/chemistry , Gold/chemistry , Nanotubes/chemistry , Prostatic Neoplasms/therapy , Aptamers, Nucleotide/therapeutic use , Cell Line, Tumor , Cell Survival/drug effects , Humans , Male , Nanotubes/ultrastructure , Phototherapy/methods , Polymers/chemistry , Silicon Dioxide/chemistry , Surface-Active Agents/chemistryABSTRACT
Compact nanostructures with highly integrated functionalities are of considerable current interest to drug delivery, multimodality imaging, and electronic devices. A key challenge, however, is how to combine individual components together without interfering or sacrificing their original electronic and optical properties. Here, we demonstrate a new class of nanocomposites with spatially separated functionalities. We further demonstrate magnetic field modulated imaging and an innovative application of this technology in cancer cell treatment, magnetolytic therapy, based on magnetically controlled mechanical damage to cell membranes.
Subject(s)
Ferrosoferric Oxide/chemistry , Magnetic Field Therapy/methods , Microscopy, Electron, Transmission/methods , Nanocomposites/chemistry , Ferric Compounds , Ferrosoferric Oxide/therapeutic use , Humans , Nanocomposites/therapeutic useABSTRACT
Semiconductor nanoparticles in the size range of 2-6 nm are of great current interest, not only because of their size-tunable properties but also because of their dimensional similarity with biological macromolecules (e.g., nucleic acids and proteins). This similarity could allow an integration of nanomaterials with biological molecules, which would have applications in medical diagnostics, targeted therapeutics, and high-throughput drug screening. Here we report new developments in preparing highly luminescent and biocompatible CdSe quantum dots (QDs), and in synthesizing QD-encoded micro- and nano-beads in the size range of 100 nm-10 microm. We show that the optical properties of ZnS-capped CdSe quantum dots are sensitive to environmental factors such as pH and divalent cations, leading to the potential use of quantum dots in molecular sensing. We also show that chemically modified proteins can be used to coat the surface of water-soluble QDs, to restore their fluorescence, and to provide functional groups for bioconjugation. For multiplexed optical encoding, we have prepared large microbeads with sizes similar to that of mammalian cells, and small nanobeads with sizes similar to that of viruses.