Effect of Star Topology Versus Linear Polymers on Antifungal Activity and Mammalian Cell Toxicity

The global increase in invasive fungal infections and the emergence of drug-resistant strains demand the urgent development of novel antifungal drugs. In this context, synthetic polymers with diverse compositions, mimicking natural antimicrobial peptides, have shown promising potential for combating fungal infections. This study investigates how altering polymer end-groups and topology from linear to branched star-like structures affects their efficacy against Candida spp., including clinical isolates. Additionally, the polymers' biocompatibility is accessed with murine embryonic fibroblasts and red blood cells in vitro. Notably, a low-molecular weight star polymer outperforms both its linear polymeric counterparts and amphotericin B (AmpB) in terms of an improved therapeutic index and reduced haemolytic activity, despite a higher minimum inhibitory concentration against Candida albicans (C. albicans) SC5314 (16-32 µg mL-1 vs 1 µg mL-1 for AmpB). These findings demonstrate the potential of synthetic polymers with diverse topologies as promising candidates for antifungal applications.

Thin Film Composite Membranes as a New Category of Alkaline Water Electrolysis Membranes

Alkaline water electrolysis (AWE) is considered a promising technology for green hydrogen (H2 ) production. Conventional diaphragm-type porous membranes have a high risk of explosion owing to their high gas crossover, while nonporous anion exchange membranes lack mechanical and thermochemical stability, limiting their practical application. Herein, a thin film composite (TFC) membrane is proposed as a new category of AWE membranes. The TFC membrane consists of an ultrathin quaternary ammonium (QA) selective layer formed via Menshutkin reaction-based interfacial polymerization on a porous polyethylene (PE) support. The dense, alkaline-stable, and highly anion-conductive QA layer prevents gas crossover while promoting anion transport. The PE support reinforces the mechanical and thermochemical properties, while its highly porous and thin structure reduces mass transport resistance across the TFC membrane. Consequently, the TFC membrane exhibits unprecedentedly high AWE performance (1.16 A cm-2 at 1.8 V) using nonprecious group metal electrodes with a potassium hydroxide (25 wt%) aqueous solution at 80 °C, significantly outperforming commercial and other lab-made AWE membranes. Moreover, the TFC membrane demonstrates remarkably low gas crossover, long-term stability, and stack cell operability, thereby ensuring its commercial viability for green H2 production. This strategy provides an advanced material platform for energy and environmental applications.

A facile and scalable strategy for constructing Janus cotton fabric with persistent antibacterial activity

Natural cotton fibers have attached considerable attention due to their excellent wearing comfort, breathability and warmth. However, it remains a challenge to devise a scalable and facile strategy to retrofit natural cotton fibers. Here, the cotton fiber surface was oxidized by sodium periodate with a mist process, then [2-(methacryloyloxy) ethyl] trimethylammonium chloride (DMC) was co-polymerized with hydroxyethyl acrylate (HA) to obtain an antibacterial cationic polymer (DMC-co-HA). The self-synthesized polymer was covalently grafted onto the aldehyde-functionalized cotton fibers via an acetal reaction between hydroxyl groups of the polymer and aldehyde groups of the oxidized cotton surface. Finally, the resulted Janus functionalized cotton fabric (JanCF) revealed robust and persistent antimicrobial activity. The antibacterial test showed that when the molar ratio of DMC/HA was 50: 1, JanCF possessed the best BR (bacterial reduction) values of 100 % against Escherichia coli and Staphylococcus aureus. Furthermore, the BR values could be maintained over 95 % even after the durability test. In addition, JanCF exhibited excellent antifungal activity against Candida albicans. The cytotoxicity assessment confirmed that JanCF exhibited a reliable safety effect on human skin. Particularly, the intrinsic outstanding characteristics (strength, flexibility, etc.) of the cotton fabric were not considerably deteriorated compared to the control samples.