Dextran microgels loaded with ZnO QDs: pH-triggered degradation under acidic conditions

Multifunctional zwitterionic microneedle dressings for accelerated healing of chronic infected wounds in diabetic rat models

Diabetic infected wounds are one of the major threats to public health but traditional wound dressings always have poor therapeutic efficacy influenced by the single treatment principle and limited penetration depth. Herein, we developed a novel kind of multifunctional degradable and removable zwitterionic microneedle dressings that could achieve multi-effective treatment of diabetic chronic wounds with a single dressing application. The substrates of microneedle dressings are composed of zwitterionic polymer polysulfobetaine methacrylate (PSBMA) and photothermal hair particles (HMPs), which can absorb wound exudate, form a barrier to the bacterial environment for the wound and exhibit an excellent photothermal bactericidal effect to promote wound healing. By loading zinc oxide nanoparticles (ZnO NPs) and asiaticoside in needle tips, drugs could diffuse in the wound area as the tips degrade to achieve highly effective antibacterial and anti-inflammatory effects and promote deep wound healing and tissue regeneration. The microneedles (MNs) were applied in diabetic rats with Staphylococcus aureus-infected wounds to demonstrate that the combination of drug and photothermal multi-treatment has accelerated tissue regeneration and collagen deposition and significantly promoted wound healing.

Fluorescent ZnO quantum dots synthesized with urea for the selective detection of Cr6+ ion in water with a wide range of concentrations

Nearly monodisperse Zinc oxide (ZnO) quantum dots (QDs) displayed yellow fluorescence were synthesized using urea as dispersant. In this paper, urea-ZnO QDs were used as fluorescent probe to detect Cr⁶⁺ in solution. The emission from the as-synthesized urea-ZnO QDs is selectively quenched when Cr⁶⁺ ions were added. Moreover, there are two linear relationships between the quenching of fluorescence intensity and the Cr⁶⁺ concentrations ranging from 4 μM to 1000 μM, with the detection limit for Cr⁶⁺ at 19.53 nM (on basis of 3σ/slope criterion). The quenching of fluorescence is attributed to aggregation of the QDs and charge transfer between the QDs and Cr⁶⁺ by measurements of transmission electron microscopy (TEM) images, UV-visible absorption spectra and fluorescence lifetime.

ZnO Nanostructures for Drug Delivery and Theranostic Applications

In the last two decades, zinc oxide (ZnO) semiconductor Quantum dots (QDs) have been shown to have fantastic luminescent properties, which together with their low-cost, low-toxicity and biocompatibility have turned these nanomaterials into one of the main candidates for bio-imaging. The discovery of other desirable traits such as their ability to produce destructive reactive oxygen species (ROS), high catalytic efficiency, strong adsorption capability and high isoelectric point, also make them promising nanomaterials for therapeutic and diagnostic functions. Herein, we review the recent progress on the use of ZnO based nanoplatforms in drug delivery and theranostic in several diseases such as bacterial infection and cancer.