Mild Hyperthermia Induced by Hollow Mesoporous Prussian Blue Nanoparticles in Alliance with a Low Concentration of Hydrogen Peroxide Shows Powerful Antibacterial Effect.

The emergence of superbacteria as well as the drug resistance of the current bacteria gives rise to worry regarding a bacterial pandemic and also calls for the development of novel ways to combat the bacteria. Here in this article, we demonstrate that mild hyperthermia induced by hollow mesoporous Prussian blue nanoparticles (HMPBNPs) in alliance with a low concentration of hydrogen peroxide (H2O2) shows a powerful inhibition effect on bacteria. Our results demonstrate that this therapeutic regime could realize almost full growth inhibition of both Gram-positive (Staphylococcus aureus, S. aureus) and -negative bacteria (Escherichia coli, E. coli), as well as potent inhibition/elimination of the S. aureus biofilm. The wound healing results indicate that combination regime of the antibacterial system could be conveniently used for wound disinfection in vivo and could promote wound healing. To our limited knowledge, this is one of the few pioneer works to apply mild hyperthermia for the combat of bacteria, which provides a novel strategy to inspire future studies.

Inhibition of breast cancer proliferation and metastasis by strengthening host immunity with a prolonged oxygen-generating phototherapy hydrogel.

Hypoxia is a potent tumor microenvironmental (TME) factor promoting immunosuppression and metastatic progression. For current anticancer therapeutic strategies, the combination of hypoxia alleviation and photodynamic therapy (PDT) might be a useful approach to further improve anticancer efficacy. In this study, we alleviated tumor hypoxia using a prolonged oxygen-generating phototherapy hydrogel (POP-Gel), which effectively elevated the oxygen level and shrank the hypoxic regions of tumors for up to 5 days evaluated by photoacoustic (PA) imaging and immunofluorescence staining, meeting the requirement of the "once injection, sustained treatment" strategy and significantly increasing PDT efficacy. The long-period improvement of the tumor hostile environment downregulated the expression of hypoxia inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF), further preventing tumor growth and metastasis. More importantly, the enhanced PDT triggered a more intense immune response, improving the inhibition of triple negative breast cancer growth even tumor elimination. The POP-Gel may contribute useful insights into the combination of hypoxia alleviation and PDT.

Curcumin-coordinated nanoparticles with improved stability for reactive oxygen species-responsive drug delivery in lung cancer therapy.

BACKGROUND: The natural compound curcumin (Cur) can regulate growth inhibition and apoptosis in various cancer cell lines, although its clinical applications are restricted by extreme water insolubility and instability. To overcome these hurdles, we fabricated a Cur-coordinated reactive oxygen species (ROS)-responsive nanoparticle using the interaction between boronic acid and Cur. MATERIALS AND METHODS: We synthesized a highly biocompatible 4-(hydroxymethyl) phenylboronic acid (HPBA)-modified poly(ethylene glycol) (PEG)-grafted poly(acrylic acid) polymer (PPH) and fabricated a Cur-coordinated ROS-responsive nanoparticle (denoted by PPHC) based on the interaction between boronic acid and Cur. The mean diameter of the Cur-coordinated PPHC nanoparticle was 163.8 nm and its zeta potential was -0.31 mV. The Cur-coordinated PPHC nanoparticle improved Cur stability in physiological environment and could timely release Cur in response to hydrogen peroxide (H2O2). PPHC nanoparticles demonstrated potent antiproliferative effect in vitro in A549 cancer cells. Furthermore, the viability of cells treated with PPHC nanoparticles was significantly increased in the presence of N-acetyl-cysteine (NAC), which blocks Cur release through ROS inhibition. Simultaneously, the ROS level measured in A549 cells after incubation with PPHC nanoparticles exhibited an obvious downregulation, which further proved that ROS depression indeed influenced the therapeutic effect of Cur in PPHC nanoparticles. Moreover, pretreatment with phosphate-buffered saline (PBS) significantly impaired the cytotoxic effect of Cur in A549 cells in vitro while causing less damage to the activity of Cur in PPHC nanoparticle. CONCLUSION: The Cur-coordinated nanoparticles developed in this study improved Cur stability, which could further release Cur in a ROS-dependent manner in cancer cells.