New Cyclam-Based Fe(III) Complexes Coatings Targeting Cobetia marina Biofilms

• Type: Article in International Scientific Journal
• Date: 2025-02-01

Authors

Fábio Carvalho (Author) FEUP; Luciana Gomes (Author) FEUP; Rita Teixeira dos Santos (Author) FEUP; Ana Carapeto (Author) Other; Filipe Mergulhão (Author) FEUP; Stephanie Almada (Author) Other; Elisabete Ribeiro Silva (Author) Other; Luís Alves (Author) Other

Journal

Title: Molecules

Vol. 30

Final page: 917

ISSN: 1420-3049

Publisher: MDPI

Indexing

ISI Web of Knowledge - 0 Citations

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Other information

Authenticus ID: P-018-1VS

DOI: 10.3390/molecules30040917

Abstract (EN): Recent research efforts to mitigate the burden of biofouling in marine environments have focused on the development of environmentally friendly coatings that can provide long-lasting protective effects. In this study, the antifouling performance of novel polyurethane (PU)-based coatings containing cyclam-based Fe(III) complexes against Cobetia marina biofilm formation was investigated. Biofilm assays were performed over 42 days under controlled hydrodynamic conditions that mimicked marine environments. Colony-forming units (CFU) determination and flow cytometric (FC) analysis showed that PU-coated surfaces incorporating 1 wt.% of complexes with formula [{R2(4-CF3PhCH2)2Cyclam}FeCl2]Cl (R = H, HOCH2CH2CH2) significantly reduced both culturable and total cells of C. marina biofilms up to 50% (R = H) and 38% (R = HOCH2CH2CH2) compared to PU-coated surface without complexes (control surface). The biofilm architecture was further analyzed using Optical Coherence Tomography (OCT), which showed that biofilms formed on the PU-coated surfaces containing cyclam-based Fe(III) complexes exhibited a significantly reduced thickness (58-61% reduction), biovolume (50-60% reduction), porosity (95-97% reduction), and contour coefficient (77% reduction) compared to the control surface, demonstrating a more uniform and compact structure. These findings were also supported by Confocal Laser Scanning Microscopy (CLSM) images, which showed a decrease in biofilm surface coverage on PU-coated surfaces containing cyclam-based Fe(III) complexes. Moreover, FC analysis revealed that exposure to PU-coated surfaces increases bacterial metabolic activity and induces ROS production. These results underscore the potential of these complexes to incorporate PU-coated surfaces as bioactive additives in coatings to effectively deter long-term bacterial colonization in marine environments, thereby addressing biofouling-related challenges.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 15