Green Antimicrobial Surfaces: Essential Oil-Infused Nanofiber Coatings for Bacterial Adhesion Prevention and Microalgae Inhibition

Overuse of antibiotics and chemical antimicrobials has created an urgent need for eco-friendly antimicrobial strategies. This research creates polycaprolactone nanofiber (PCL_NF) coated and infused with Eucalyptus radiata essential oil (ERO) surfaces (PCL_NFCS15-ERO) to reduce bacterial adhesion and microalgal proliferation while preventing the development of antimicrobial resistance. Uniform and bead-free electrospun PCL_NF (average diameter 995 +/- 0.3 nm) were produced and coated onto glass substrates. PCL_NFCS15-ERO surfaces significantly reduced Pseudomonas aeruginosa attachment, from 162 +/- 1.7 x 105 CFU/mL on 3 days to 7.5 +/- 0.4 x 105 CFU/mL. The anti-microalgal activity of PCL_NFCS15-ERO was assessed using Chlorella sp. as a model organism through OD680, chlorophyll (a + b) content, and cell counting over 14 days. Results showed a significant reduction, with OD680 values in the control group decreasing from 0.442 +/- 0.008 to 0.002 by 14 days, effectively inhibiting Chlorella growth. Unlike the proliferation observed on control surfaces, chlorophyll and cell count confirmed the effective antifouling activity of PCL_NFCS15-ERO. Additionally, cytotoxicity and cellular attachment tests on HEK292T-ATCC demonstrated good biocompatibility. Overall, PCL_NFCS15-ERO surfaces offer a biodegradable, non-toxic, and effective alternative for reducing microbial attachment with significant potential for marine and biomedical applications. This approach supports sustainable antimicrobial development and reduces reliance on harmful chemical agents.