Antimicrobial resistance (AMR) presents an escalating global challenge as conventional antibiotic treatments become less effective. In response, photodynamic therapy (PDT) and photothermal therapy (PTT) have emerged as promising alternatives. While rooted in ancient practices, these methods have evolved with modern innovations, particularly through the integration of lasers, refining their efficacy. PDT harnesses photosensitizers to generate reactive oxygen species (ROS), which are detrimental to microbial cells, whereas PTT relies on heat to induce cellular damage. The key to their effectiveness lies in the utilization of photosensitizers, especially when integrated into nano- or micron-scale supports, which amplify ROS production and enhance antimicrobial activity. Over the last decade, carbon dots (CDs) have emerged as a highly promising nanomaterial, attracting increasing attention owing to their distinctive properties and versatile applications, including PDT and PTT. They can not only function as photosensitizers, but also synergistically combine with other photosensitizers to enhance overall efficacy. This review explores the recent advancements in CDs, underscoring their significance and potential in reshaping advanced antimicrobial therapeutics.

Inflammatory bowel disease (IBD) are chronic inflammatory conditions which cause significant patient morbidity. Local drug delivery to the colon can improve treatment efficacy and reduce side effects associated with IBD treatment. Smart drug delivery systems are designed to regulate the release of therapeutic agents at the desired site of action. pH-responsive drug carriers have been previously utilised for improved oral drug delivery beyond stomach harsh conditions. Additionally, the colon possesses a diverse microbiome secreting bioactive molecules e.g., enzymes, that can be exploited for targeted drug delivery. We herein synthesised and characterised a 2-hydroxyethyl methacrylate and methacrylic acid copolymer, crosslinked with an azobenzyl crosslinker, that displayed pH- and enzyme-responsive properties. The swelling and drug release from hydrogel were analysed in pH 1.2, 6.5 and 7.4 buffers, and in the presence of rat caecal matter using metronidazole and mesalamine as model BCS Class I and IV drugs, respectively. Swelling studies displayed pH-responsive swelling behaviour, where swelling was maximum at pH 7.4 and minimum at pH 1.2 (69 % versus 32 %). Consequently, drug release was limited in gastric and small intestinal conditions but increased significantly when exposed to colonic conditions containing caecal matter. This system displays promising capacity for achieving colon-targeted drug delivery with enhanced dissolution of poorly water-soluble drugs for local treatment of IBD and other colon-targeted therapies.

Microbial fouling is a costly issue, which impacts a wide range of industries, such as healthcare, food processing, and construction industries, and improved strategies to reduce the impact of fouling are urgently required. Slippery liquid-infused porous surfaces (SLIPSs) have recently been developed as a bioinspired approach to prevent antifouling. Here, we report the development of slippery, superhydrophilic surfaces by infusing roughened poly(vinyl chloride) (PVC) substrates with phosphonium ionic liquids (PILs). These surfaces were capable of reducing viable bacterial adherence by Staphylococcus aureus and Pseudomonas aeruginosa by >6 log₁₀ cfu mL^–1 after 24 h under static conditions relative to control PVC. Furthermore, we report the potential of a series of asymmetric quaternary alkyl PILs with varying alkyl chain lengths (C₄–C₁₈) and counteranions to act as antimicrobial agents against both Gram +ve and Gram −ve bacteria and illustrate their potential as antimicrobial alternatives to traditional fluorinated lubricants commonly used in the synthesis of SLIPSs.

Hydrophilic-coated intermittent catheters have improved the experience of intermittent urinary catheterization for patients compared to conventional gel-lubricated uncoated catheters. However, the incorporation of polyvinylpyrrolidone (PVP) within hydrophilic coatings can lead to significant issues with coating dry-out. Consequently, increased force on catheter withdrawal may cause complications, including urethral microtrauma and pain. Standard methods of evaluating catheter lubricity lack physiological relevance and an understanding of the surface interaction with the urethra. The tribological performance and urethral interaction of commercially available hydrophilic PVP-coated catheters and a coating-free integrated amphiphilic surfactant (IAS) catheter were evaluated by using a biomimetic urethral model designed from a modified coefficient of friction (CoF) assay. T24 human urothelial cells were cultured on customized silicone sheets as an alternate countersurface for CoF testing. Hydrophilic PVP-coated and coating-free IAS catheters were hydrated and the CoF obtained immediately following hydration, or after 2 min, mimicking in vivo indwell time for urine drainage. The model was observed for urethral epithelial cell damage postcatheterization. The majority of hydrophilic PVP-coated catheters caused significantly greater removal of cells from the monolayer after 2 min indwell time, compared to the IAS catheter. Hydrophilic PVP-coated catheters were shown to cause more cell damage than the coating-free IAS catheter. A biomimetic urethral model provides a more physiologically relevant model for understanding the factors that govern the frictional interface between a catheter surface and urethral tissue. From these findings, the use of coating-free IAS catheters instead of hydrophilic PVP-coated catheters may help reduce urethral microtrauma experienced during catheter withdrawal from the bladder, which may lead to a lower risk of infection.

Ex situ biofilm samples were used to study the interactions between SERS-enhancing Ag and Au particles and biofilm components without the complexity associated with highly structured in situ biofilms.