WCN26-935 THIOREDOXIN-DEFICIENT RATS AS A TRANSLATIONAL MODEL FOR CHRONIC KIDNEY DISEASE: MITOCHONDRIAL DYSFUNCTION DRIVES PROGRESSIVE RENAL FAILURE THROUGH OXIDATIVE STRESS-MEDIATED PATHWAYS

Introduction: Catheter-related infections are a significant concern, leading to increased morbidity, mortality, and hospitalization rates.These infections tend to be more prevalent than infections from other vascular access types used in hemodialysis.Staphylococcus aureus is the primary bacterium responsible, with biofilms formed on catheter surfaces, which are highly resistant to antibiotics.These biofilms develop when S. aureus bonds with proteins coating the catheter, such as fibrinogen and thrombospondin.The rise of multidrug-resistant bacterial strains has emphasized the need for new treatment options, with natural products gaining attention for their antimicrobial, antiinflammatory, and antioxidant properties.Anacardic acid (AA), a key component of cashew nut shell liquid (CNSL), exhibits antimicrobial activity by interacting with the plasma membrane of target cells, causing rupture.AA has shown effectiveness against S. aureus, including resistant strains, and can enhance the activity of standard bactericides when used in combination.Nanomedicine, particularly the use of nanoparticles, is a promising approach to overcoming antibiotic resistance.Nanoparticles can enhance the antimicrobial effects of drugs and inhibit biofilm formation.Zein, a protein derived from corn, is an effective drug carrier due to its biocompatibility, biodegradability, and ability to deliver lipophilic drugs.This study aims to evaluate the in vitro antimicrobial effect of AA loaded in zein nanoparticles, impregnated in hemodialysis catheters, against S. aureus.Methods: This in vitro experimental study evaluated four groups: hydroethanolic solution, zein nanoparticles, zein nanoparticles with anacardic acid, and a positive control with vancomycin.Inhibition zones were measured using the agar diffusion method with three samples from each group and three technical replicates.Anacardic acid was purified from cashew shells using a cold solvent extraction method.Zein nanoparticles containing anacardic acid were prepared via nanoprecipitation, and their size, polydispersity, zeta potential, and pH were characterized.Polyurethane catheter segments were sterilized and immersed in the test solutions for five minutes prior to use in experiments.Staphylococcus aureus ATCC 25923 was cultured in BHIglucose broth for biofilm experiments.Catheters coated with the test solutions were placed on BHI agar plates inoculated with S. aureus, and inhibition zones were measured after six days of incubation at 37 C. Biofilms were formed by adding S. aureus suspension to a 24-well plate with BHI-glucose broth.Catheters were submerged and incubated at 37 C for 48 hours.The biofilm was quantified by serial dilution and plating on BHI agar.Data were expressed as means and standard deviations, with normality tested using the Shapiro-Wilk test, followed by ANOVA and Tukey's test for comparison, considering p < 0.05.Results: The antimicrobial activity of anacardic acid (AA) coating on catheters was evaluated through agar diffusion tests and biofilm formation assays.In the agar diffusion tests, catheters immersed in hydroethanolic and zein nanoparticle solutions (without AA) showed no inhibition of S. aureus growth, indicating no antimicrobial effect.Although the vancomycin group exhibited larger inhibition halos compared to the AA group, the difference was not statistically significant (p > 0.05).In biofilm inhibition tests, no significant difference in colony-forming units (CFU/mL) was observed among the ethanol, zein nanoparticle, and zein nanoparticle + AA groups (p > 0.05).However, the vancomycin group showed a significantly different response (p < 0.0001), demonstrating its superior effectiveness in inhibiting biofilm formation.Conclusion: Anacardic acid in zein nanoparticles shows antimicrobial activity against Staphylococcus aureus, with coated catheters retaining these properties.However, no effect was seen in S. aureus biofilms on polyurethane catheters.Further studies are needed to assess the impact under different immersion conditions and higher concentrations.I have no potential conflict of interest to disclose.I did not use generative AI and AI-assisted technologies in the writing process.