Napyradiomycin-based coatings: Promising eco-friendly, sustainable and circular solutions for effective marine antibiofouling

This study introduces a groundbreaking approach to marine antifouling by incorporating napyradiomycins extracts, meroterpenoids derived from marine actinomycetes, into biocide-free coatings, establishing the first comprehensive assessment of their dual antimicro- and antimacrofouling potential. By leveraging naturally derived bioactives, this work pioneers a sustainable alternative to copper- and ivermectin-based formulations, aligning with circular bioeconomy and green chemistry principles. At low concentrations (31.25 µg/mL), napyradiomycin-based coatings demonstrated effective macrofouling prevention with no detectable toxicity, while higher concentrations (10 mg/mL) rivaled conventional coatings in efficacy and induced lethality. Uniquely, ecotoxicological evaluations using oxidative stress biomarkers, supported by mussels’ survival assays, revealed no significant adverse effects at the lower concentration, showcasing an environmentally friendly profile rarely achieved in antifouling solutions. Despite the promising results, limitations under current static laboratory conditions include no antibiofilm activity and the need for long-term field validation under dynamic marine environments. These challenges, however, offer valuable opportunities for future research in formulation refinement, release profile optimization, and biocide loading thresholds. By combining antimacrofouling efficacy with low ecological impact and scalability potential, these coatings represent a promising advance in marine coating technology, warranting clear path forward for enhancing sustainability in marine industry practices while protecting marine biodiversity.