Metal-Polymer Complexes as Antibacterial Agents: Characterization and Antibacterial Activity of Metal-Polymer Nanocomposite Based on Copolymers of Polyethylene(Propylene)Glycolmaleates with Acrylic Acid

The article presents the results of the synthesis and study of the structure of metal-polymer complexes p-EGM: АА/Ag, p-EGM: АА/Ni, p-EGM:АА/Ag-Ni, p-PGM:АА/Ag, p-PGM:АА/Ni, p-PGM:АА/Ag-Ni based on copolymers of polyethylene(propylene)glycolmaleates with acrylic acid and metals, which have been characterized using microscopy, spectroscopy and thermogravimetry. The antimicrobial activity of a new metal-polymer nanocomposite p-PGM/АА-Ag was studied, which is showing high efficiency against standard strains of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus.

Fast Gelation of Poly(ionic liquid)-Based Injectable Antibacterial Hydrogels

Traditional antibacterial hydrogels have a broad-spectrum bactericidal effect and are widely used as wound dressings. However, the biological toxicity and drug resistance of these antibacterial hydrogels cannot meet the requirements of long-term clinical application. Imidazolium poly(ionic liquids) (PILs) are polymeric antibacterial agents exhibiting strong antibacterial properties, as they contain a strong positive charge. In this study, two imidazolium PILs, namely poly(N-butylimidazolium propiolic acid sodium) (PBP) and poly(N-(3,6-dioxaoctane) imidazolium propiolic acid sodium) (PDP), as high efficiency antibacterial agents, were synthesized by polycondensation reaction. Then, the PILs were compounded with polyethylene glycol (PEG) by a thiol-yne click reaction to prepare injectable antibacterial hydrogels. An in vitro assay showed that the injectable antibacterial hydrogels could not only quickly kill Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), but also had low toxicity for human skin fibroblasts cells (HSFs) and human umbilical vein endothelial cells (HUVECs), respectively. Additionally, the lipopolysaccharide (LPS) inflammation model revealed that the injectable antibacterial hydrogels also had anti-inflammatory effects, which would be advantageous to accelerate wound healing.

Analysis of the clinical pipeline of treatments for drug resistant bacterial infections: despite progress, more action is needed

There is an urgent global need for new strategies and drugs to control and treat multi-drug resistant bacterial infections. In 2017, the World Health Organization (WHO) released a list of 12 antibiotic-resistant priority pathogens and began to critically analyze the antibacterial clinical pipeline. This review analyzes ‘traditional’ and ‘non-traditional’ antibacterial agents and modulators in clinical development current on 30 June 2021 with activity against the WHO priority pathogens, mycobacteria and Clostridioides difficile. Since 2017, 12 new antibacterial drugs have been approved globally, but only vaborbactam belongs to a new antibacterial class. Also innovative is the cephalosporin derivative cefiderocol, which incorporates an iron-chelating siderophore that facilitates Gram-negative bacteria cell entry. Overall, there were 76 antibacterial agents in clinical development (45 traditional and 31 non-traditional) with 28 in Phase 1, 32 in Phase 2, 12 in Phase 3 and four under regulatory evaluation. Forty-one out of 76 (54%) targeted WHO priority pathogens, 16 (21%) against mycobacteria, 15 (20%) against C. difficile and 4 (5%) are non-traditional agents with broad spectrum effects. Nineteen of the 76 antibacterial agents have new pharmacophores and four of these have new modes of actions not previously exploited by marketed antibacterial drugs. Despite there being 76 antibacterial clinical candidates, this analysis indicated that there were still relatively few clinically differentiated antibacterial agents in late-stage clinical development, especially against critical Priority Pathogens. We believe that future antibacterial R&D should focus on the development of innovative and clinically differentiated candidates that have clear and feasible progression pathways to the market.

Determination of Parabens, Bisphenol A and Its Analogs, Triclosan, and Benzophenone-3 Levels in Human Urine by Isotope-Dilution-UPLC-MS/MS Method Followed by Supported Liquid Extraction

The development of a rapid analytical approach for determining levels of antibacterial agents, plasticizers, and ultraviolet filters in biosamples is crucial for individual exposure assessment. We developed an analytical method to determine the levels of four parabens—bisphenols A (BPA) and its analogs, triclosan (TCS), triclocarban, and benzophenone-3 (BP-3)—in human urine. We further measured the levels of these chemicals in children and adolescents. We used a supported liquid extraction (SLE) technique coupled with an isotope-dilution ultraperformance liquid chromatography-tandem mass spectrometry (ID-UPLC-MS/MS) method to assess the detection performance for these chemicals. Forty-one urine samples from 13 children and 28 adolescents were assessed to demonstrate the capability and feasibility of our method. An acceptable recovery (75.6–102.4%) and matrix effect (precision < 14.2%) in the three-level spiked artificial urine samples were achieved, and good performance of the validated ID-UPLC-MS/MS method regarding linearity, limits of detection, and quantitation was achieved. The within-run and between-run accuracy and precision also demonstrated the sensitivity and stability of this analytical method, applied after SLE. We concluded that the ID-UPLC-MS/MS method with SLE pretreatment is a valuable analytical method for the investigation of urinary antibacterial agents, plasticizers, and ultraviolet filters in humans, useful for human biomonitoring.

A Review on Cellulose-based Materials for Biomedicine

There are various biomaterials in nature, but none fulfills all the requirements. Cellulose, eco-friendly material-based biopolymers, have been advanced biomedicine to satisfy most market demand and circumvent many ecological concerns. This review aims to present an overview of the state of the art in cellulose's knowledge and technical biomedical applications. It included an extensive bibliography of recent research findings for fundamental and applied investigations. The chemical structure of cellulose allows modifications and simple conjugation with several materials, including nanoparticles, without tedious efforts. Cellulose-based materials were used for biomedicine applications such as antibacterial agents, antifouling, wound healing, drug delivery, tissue engineering, and bone regeneration. They advanced the applications to be cheap, biocompatible, biodegradable, easy for shaping and processing into different forms, with suitable chemical, mechanical and physical properties.