Tomato leaves, typically discarded during harvest, are a rich yet underutilized source of bioactive compounds. This study aimed to valorize tomato leaves by optimizing the extraction of their phenolic compounds using a water-based method and response surface methodology. The optimal conditions, notably heating a mixture of 1:50 solid-to-liquid ratio at 71 °C for 29 min, yielded the most total phenolic content and antioxidant activity. The biological activities of the lyophilized tomato leaf extract (TLE) were then assessed. TLE showed dose-dependent antimicrobial activity against Escherichia coli and Candida albicans, but neither against Pseudomonas aeruginosa nor Staphylococcus aureus. In addition, it demonstrated moderate cytotoxicity against MCF-7 breast cancer cells with an IC₅₀ value of 114.5 µg/mL. Interestingly, the extract significantly reduced intracellular reactive oxygen species levels in RAW 264.7 macrophages, supporting its anti-inflammatory potential. LC-MS analysis identified rutin (45.21%), 4-hydroxycoumarin (13.60%), and α-tomatine (12.37%) as the major chemical constituents in TLE, suggesting contributing effects behind the observed bioactivities. These results support the potential of tomato leaf extract as an eco-friendly source for functional ingredients, transforming agricultural waste through green extraction into valuable applications for nutraceuticals and sustainable product development.

Catheter-associated urinary tract infections are often caused by biofilm formation on device surfaces. This paper presents an antimicrobial catheter-coating hydrogel comprising p(HEMA) and carboxyl-functionalized p(HEMA-co-MA), loaded with benzalkonium chloride (BAC) to increase hydrophilicity, pH responsiveness, and antibiofilm activity. Hydrogels were prepared by free-radical polymerization, loaded with BAC via swelling, and their physicochemical properties were characterized. Furthermore, microbiological assessment focused on the detection of MIC/MBC/MFC, disk diffusion, biofilm assays, SEM imaging, and RT-qPCR sequencing were used to determine the impact on biofilm-related gene expression to evaluate antimicrobial activity against major catheter-associated urinary tract infection (CAUTI)-associated pathogens and identify the higher BAC loading p(HEMA) and enhanced hydrophilicity and pH-responsive swelling (p(HEMA-co-MA)). The two hydrogels exhibited a wide range of antimicrobial activity and provided lasting inhibition for up to 8 days. It is worth noting that the MA-functionalized hydrogel exhibited a high intrinsic antifouling property, and biofilm development was reduced by more than 85% in BAC-loaded formulations. SEM and gene-expression studies showed reduced microbial adhesion and substantial repression of virulence and biofilm-associated genes. In summary, BAC-loaded p(HEMA) and p(HEMA-co-MA) coatings exhibit strong antimicrobial and antiadhesive properties, and the incorporation of MA results in more effective biofilm suppression, which supports their future use as advanced catheter coatings to prevent the development of device-related infections.