Multifunctional Protective Strategies for Wooden Cultural Heritage: Antimicrobial Efficacy of Polyacrylic Resins, Siloxane Coupling Agents, and Silver Nanoparticles

Andreea Stefania Dumbrava^1,2Viorica Maria Corbu^3,4Ioana Cristina Marinas³Radu Pericleanu²Liliana Marinescu⁵Ludmila Motelica^6,7,8Doina Roxana Trusca⁸Nicoleta Ianovici⁹Tatiana Eugenia Sesan^10,2Irina Gheorghe^2,3*Denisa Ficai^5,7,8Ovidiu-Cristian Oprea^5,7,8Anton Ficai^5,7,8Mariana Carmen Chifiriuc^2,3,7

• ¹Department of Technological Irradiation (IRASM), Horia Hulubei National Institute of Physics and Nuclear Engineering–IFIN-HH, Magurele, Romania
• ²Department of Microbiology and Botany, Faculty of Biology, University of Bucharest, Bucharest, Romania
• ³Research Institute of the University of Bucharest, University of Bucharest, Bucharest, Romania
• ⁴Department of Genetics, Faculty of Biology, University of Bucharest, Bucharest, Romania
• ⁵Faculty of Chemical Engineering and Biotechnologies, National University of Science and Technology Politehnica Bucharest, Bucharest, Romania
• ⁶Research Center for Advanced Materials, Products and Processes, National University of Science and Technology Politehnica Bucharest, Bucharest, Romania
• ⁷Academy of Romanian Scientist, Bucharest, Romania
• ⁸National Center for Micro and Nanomaterials, National University of Science and Technology Politehnica Bucharest, Bucharest, Romania
• ⁹Environmental Biology and Biomonitoring Research Center, Faculty of Chemistry, Biology, Geography, Department of Biology, West University of Timisoara, Timisoara, Romania
• ¹⁰Romanian Academy of Agricultural and Forestry Sciences, Bucharest, Romania

This study evaluates two innovative protective treatments for wooden cultural heritage objects vulnerable to biodeterioration. The first involves polyacrylic resin solutions embedded with silver nanoparticles (AgNPs), while the second uses the siloxane-based coupling agent 3mercaptopropyltrimethoxysilane (3-MPTMS) to enhance AgNP adhesion to wood surfaces. Methods: Antimicrobial, anti-biofilm, and anti-metabolic activities were assessed using both qualitative and quantitative assays against biodeteriogenic strains (Penicillium chrysogenum, Bacillus cereus, and Bacillus megaterium). Additional analyses included extracellular nitric oxide (NO) production, phytotoxicity testing on Allium cepa, and correlations with biochemical parameters.Polyacrylic resins incorporating AgNPs exhibited significant antimicrobial properties, with stronger effects against bacteria. Treatments combining AgNPs with MPTMS or acrylic resins demonstrated enhanced inhibitory effect on microbial viability, adhesion, and degradative enzymes secretion. Subinhibitory concentrations of resin solutions modulated the extracellular NO levels, correlated with metabolic stress responses. Notably, ecotoxicity testing confirmed minimal phytotoxic impact, supporting the safety of these materials for cultural heritage applications.The findings support the use of AgNP-enhanced polyacrylic resins and silanized coatings as effective, non-destructive conservation strategies for wooden heritage artifacts, offering durable protection against microbial deterioration while maintaining environmental safety.