ELECTROSPUN PCL MATS AS BACTERIAL SUPPORTS FOR SUSTAINABLE BIOCLEANING IN CULTURAL HERITAGE CONSERVATION

Biocleaning represents a sustainable and non-invasive strategy for the conservation of Cultural Heritage, leveraging the metabolic capabilities of selected microorganisms to remove biofilms, surface contaminants, and alteration products without damaging original materials [1]. In this work, we explore the development of electrospun poly(ε-caprolactone) (PCL) mats, as innovative microbial carriers designed to enhance the precision and applicability of biocleaning interventions. PCL is a synthetic, biodegradable polyester widely used in biomedical fields due to its biocompatibility, mechanical robustness, and slow, non-toxic degradation. Its moderate hydrophobicity, nanofibrous structure, and tunable surface roughness make it especially suitable for promoting bacterial adhesion [2]. The mats were fabricated using electrospinning, a technique that yields highly porous scaffolds with a high surface-area-to-volume ratio, mimicking the natural extracellular matrix and optimizing conditions for bacterial viability. Comprehensive physicochemical characterization of the mats was performed via mechanical testing, Atomic Force Microscopy (AFM), contact angle measurements, and SEM-EDS to evaluate structural and surface properties. To assess the mats’ potential for biocleaning, we tested the metabolic profiles of Bacillus subtilis and Pseudomonas stutzeri, two species with a documented history of safe and effective use in heritage restoration [3]. Their enzymatic activities—lipolytic, cellulolytic, proteolytic, and chitinolytic—were evaluated through qualitative plate assays, confirming their ability to degrade complex organic residues commonly found on cultural substrates. Bacterial colonization and viability on the PCL surfaces were further studied using a fluorescence-based assay. To evaluate the feasibility of storage and long-term deployment, lyophilization was applied, and bacterial viability was monitored after one and two weeks. Our findings support the use of PCL electrospun mats as efficient microbial supports for biocleaning applications. This system offers a reproducible, controllable, and ready-to-use tool for the targeted removal of surface contaminants on artworks, combining effectiveness with environmental and material safety.