Peelable Alginate Films Reinforced by Carbon Nanofibers Decorated with Antimicrobial Nanoparticles for Immediate Biological Decontamination of Surfaces

Gabriela Toader; Aurel Diacon; Edina Rusen; Ionel I Mangalagiu; Mioara Alexandru; Florina Lucica Zorilă; Alexandra Mocanu; Adina Boldeiu; Ana Mihaela Gavrilă; Bogdan Trică; Daniela Pulpea; Mădălina Ioana Necolau; Marcel Istrate

doi:10.3390/nano13202775

Peelable Alginate Films Reinforced by Carbon Nanofibers Decorated with Antimicrobial Nanoparticles for Immediate Biological Decontamination of Surfaces

Nanomaterials (Basel). 2023 Oct 16;13(20):2775. doi: 10.3390/nano13202775.

Authors

Gabriela Toader¹, Aurel Diacon^{1

2}, Edina Rusen², Ionel I Mangalagiu³, Mioara Alexandru⁴, Florina Lucica Zorilă^{4

5}, Alexandra Mocanu^{2

6}, Adina Boldeiu⁶, Ana Mihaela Gavrilă⁷, Bogdan Trică⁷, Daniela Pulpea¹, Mădălina Ioana Necolau^{2

8}, Marcel Istrate⁹

Affiliations

¹ Military Technical Academy "Ferdinand I", 39-49 G. Cosbuc Blvd., 050141 Bucharest, Romania.
² Faculty of Chemical Engineering and Biotechnologies, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061 Bucharest, Romania.
³ Faculty of Chemistry, Alexandru Ioan Cuza University of Iasi, 11 Carol 1st Blvd., 700506 Iasi, Romania.
⁴ Microbiology Laboratory, Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, 30 Reactorului St., 077125 Bucharest, Romania.
⁵ Department of Genetics, Faculty of Biology, University of Bucharest, 91-95 Splaiul Indepententei, 050095 Bucharest, Romania.
⁶ National Institute for Research and Development in Microtechnologies-IMT Bucharest, 126A Erou Iancu Nicolae Street, 077190 Bucharest, Romania.
⁷ National Institute of Research and Development for Chemistry and Petrochemistry, 202 Splaiul Independentei, 060041 Bucharest, Romania.
⁸ Advanced Polymer Materials Group, University Politehnica of Bucharest, 1-7 Polizu Street, 011061 Bucharest, Romania.
⁹ S.C. Stimpex S.A., 46-48 Nicolae Teclu Street, 032368 Bucharest, Romania.

Abstract

This study presents the synthesis and characterization of alginate-based nanocomposite peelable films, reinforced by carbon nanofibers (CNFs) decorated with nanoparticles that possess remarkable antimicrobial properties. These materials are suitable for immediate decontamination applications, being designed as fluid formulations that can be applied on contaminated surfaces, and subsequently, they can rapidly form a peelable film via divalent ion crosslinking and can be easily peeled and disposed of. Silver, copper, and zinc oxide nanoparticles (NPs) were synthesized using superficial oxidized carbon nanofibers (CNF-ox) as support. To obtain the decontaminating formulations, sodium alginate (ALG) was further incorporated into the colloidal solutions containing the antimicrobial nanoparticles. The properties of the initial CNF-ox-NP-ALG solutions and the resulting peelable nanocomposite hydrogels (obtained by crosslinking with zinc acetate) were assessed by rheological measurements, and mechanical investigations, respectively. The evaluation of Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) for the synthesized nanoparticles (silver, copper, and zinc oxide) was performed. The best values for MIC and MBC were obtained for CNF-ox decorated with AgNPs for both types of bacterial strains: Gram-negative (MIC and MBC values (mg/L): E. coli-3 and 108; P. aeruginosa-3 and 54) and Gram-positive (MIC and MBC values (mg/L): S. aureus-13 and 27). The film-forming decontaminating formulations were also subjected to a microbiology assay consisting of the time-kill test, MIC and MBC estimations, and evaluation of the efficacity of peelable coatings in removing the biological agents from the contaminated surfaces. The best decontamination efficiencies against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa varied between 97.40% and 99.95% when employing silver-decorated CNF-ox in the decontaminating formulations. These results reveal an enhanced antimicrobial activity brought about by the synergistic effect of silver and CNF-ox, coupled with an efficient incorporation of the contaminants inside the peelable films.

Keywords: alginate; antimicrobial activity; carbon nanofibers; decontamination; nanocomposites; nanoparticles; nanosilver.

Grants and funding

This work was financially supported by the Ministry of Research, Innovation, and Digitalization (UEFISCDI) through PN-III-P1-1.1-PD-2021—ctr. no. PD69/2022 and PN-III-P2-2.1-PED-2021—ctr. no. 672PED/2022. Aurel Diacon gratefully acknowledges financial support from the Competitiveness Operational Program 2014–2020, Action 1.1.3: Creating synergies with RDI actions of the EU’s HORIZON 2020 framework program and other international RDI programs, MySMIS Code 108792, Acronym project “UPB4H”, financed by contract: 250/11.05.2020.