Heteroaryl-Ethylenes as New Lead Compounds in the Fight against High Priority Bacterial Strains

One-Pot Synthesis of Luminescent and Photothermal Carbon Boron-Nitride Quantum Dots Exhibiting Cell Damage Protective Effects

Zero-dimensional boron nitride quantum dots (BNQDs) are arousing interest for their versatile optical, chemical, and biochemical properties. Introducing carbon contents in BNQDs nanostructures is a great challenge to modulate their physicochemical properties. Among the carbon moieties, phenolic groups have attracted attention for their biochemical properties and phenol-containing nanomaterials are showing great promise for biomedical applications. Herein, the first example of direct synthesis of water dispersible BNQDs exposing phenolic and carboxylic groups is presented. The carbon-BNQDs are prepared in a single-step by solvent-assisted reaction of urea with boronic reagents and are characterized by optical absorption, luminescence, Raman, Fourier transform infrared and NMR spectroscopy, X-ray photoelectron spectroscopy, dynamic light scattering, and atomic force microscopy. The carbon-BNQDs exhibit nanodimension, stability, high photothermal conversion efficiency, pH-responsive luminescence and Z-potential. The potential of the carbon-BNQDs to provide photothermal materials in solid by embedding in agarose substrate is successfully investigated. The carbon-BNQDs exhibit biocompatibility on colorectal adenocarcinoma cells (Caco-2) and protective effects from chemical and oxidative stress on Caco-2, osteosarcoma (MG-63), and microglial (HMC-3) cells. Amplicon mRNA-seq analyses for the expression of 56 genes involve in oxidative-stress and inflammation are performed to evaluate the molecular events responsible for the cell protective effects of the carbon-BNQDs.

Heteroaryl-Ethylenes as New Effective Agents for High Priority Gram-Positive and Gram-Negative Bacterial Clinical Isolates

The World Health Organization has identified antimicrobial resistance as a public health emergency and developed a global priority pathogens list of antibiotic-resistant bacteria that can be summarized in the acronym ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacterales species), reminding us of their ability to escape the effect of antibacterial drugs. We previously tested new heteroaryl-ethylene compounds in order to define their spectrum of activity and antibacterial capability. Now, we focus our attention on PB4, a compound with promising MIC and MBC values in all conditions tested. In the present study, we evaluate the activity of PB4 on selected samples of ESKAPE isolates from nosocomial infections: 14 S. aureus, 6 E. faecalis, 7 E. faecium, 12 E. coli and 14 A. baumannii. Furthermore, an ATCC control strain was selected for all species tested. The MIC tests were performed according to the standard method. The PB4 MIC values were within very low ranges regardless of bacterial species and resistance profiles: from 0.12 to 2 mg/L for S. aureus, E. faecalis, E. faecium and A. baumannii. For E. coli, the MIC values obtained were slightly higher (4–64 mg/L) but still promising. The PB4 heteroaryl-ethylenic compound was able to counteract the bacterial growth of both high-priority Gram-positive and Gram-negative clinical strains. Our study contributes to the search for new molecules that can fight bacterial infections, in particular those caused by MDR bacteria in hospitals. In the future, it would be interesting to evaluate the activity of PB4 in animal models to test for its toxicity.

New Antimicrobial Options in the Clinical Practice of Infections Caused by Difficult-to-Treat Pathogens: A Global Opportunity for Public Health

Antimicrobial resistance (AMR) is a serious cause of concern for public health [...].