Zinc Oxide Nanoparticles Dispersed in Ionic Liquids Show High Antimicrobial Efficacy to Skin-Specific Bacteria
ACS APPLIED MATERIALS & INTERFACES
Authors: Aditya, Anusha; Chattopadhyay, Sabyasachi; Jha, Diksha; Gautam, Hemant K.; Maiti, Souvik; Ganguli, Munia
Abstract
Zinc oxide (ZnO) nanoparticles have been shown in the literature to have antibacterial properties and have been widely used in antibacterial formulations. However, one of the problems with ZnO nanoparticles is their tendency to aggregate, thereby causing damage to normal cells and lowering their antibacterial efficacy during application. In this work, we have attempted to avoid this by using a combination of ZnO nanoparticles and ionic liquids, a class of low melting salts containing organic cations and organic/inorganic anions that show antibacterial property as well, and tested the antibacterial activity of this dispersion. ZnO nanoparticles of 60 nm were dispersed in two different ionic liquids-choline acetate (IL1) and 1-butyl-3-methylimidazolium chloride (IL2)-to achieve high dispersibility, whereas ZnO dispersed in phosphate-buffered saline was taken as a control. These dispersions were tested on four strains-Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae, and Staphylococcus epidermidis. Maximum efficiency was obtained for ZnO nanoparticles dispersed in imidazolium-based ionic liquids against skin-specific S. epidermidis. Skin infections induced by S. epidermidis are prevalent in hospital-acquired diseases. In most cases, traditional antibiotic-based therapies fail to combat such infections. Our strategy of developing a dispersion of ZnO nanoparticles in ionic liquids shows superior antibacterial efficacy in comparison to that shown individually by ZnO nanoparticles or ionic liquids. We have also established that the mechanism of killing this skin-specific bacterium is possibly through the production of reactive oxygen species leading to bacterial cell lysis. Further, we showed that this formulation is biocompatible and nontoxic to normal keratinocyte cells even under coculture conditions.
Back to the Future: Rethinking and Retooling IL2 in the Immune Checkpoint Inhibitor Era
CANCER DISCOVERY
Authors: Sullivan, Ryan J.
Abstract
IL2 is a type I cytokine that is associated, when given at high doses intravenously, with durable regression in a subset of patients with metastatic melanoma and renal cell carcinoma, yet high toxicity limits its use. NKTR-214 is a novel pegylated IL2 with minor clinical activity as a single agent, but a favorable toxicity profi le and compelling pharmacodynamic effects that predict utility in combination with immune checkpoint inhibition.