Cultural heritage stone materials frequently experience significant discoloration induced by copper corrosion products, especially calcareous stones associated with bronze or copper statues and architectural elements. This alteration originates from the corrosion of unprotected copper, resulting in the formation of various Cu minerals and the migration of soluble ions to adjacent stone materials. Traditional cleaning methods involve mechanical, chemical, and laser techniques, which are generally time-consuming, costly, not ecological, or can possibly damage original materials. The loading of highly effective chelating agents, such as ethylenediaminetetraacetic acid (EDTA), into hydrogels has recently been exploited. However, the preference for synthetic hydrogels has been prominent until now, although they lack renewability and biodegradability and require high costs. This study explores for the first time the potential to clean copper corrosion with bacterial nanocellulose (BC) loaded with EDTA as a biologically based, sustainable, and biodegradable hydrogel. The BC hydrogel was characterised by field emission–scanning electron microscopy (FE–SEM), X-ray diffraction analysis (XRD), attenuated total reflectance–Fourier transform infrared spectroscopy (ATR–FTIR), simultaneous thermal analysis (TG-DSC), and tensile testing. It revealed a nano-fibrous structure with high crystallinity and purity and mechanical properties suitable for cultural heritage applications. The EDTA-loaded hydrogel effectively removed copper stains from marble after 120 min of application. Micro-Raman and colorimetric analyses assessed the cleaning efficacy. The study introduces bacterial nanocellulose as a green and effective alternative for heritage conservation, aligning with sustainable methodologies in stone conservation.

Coffee silverskin (CSS), the major by-product of coffee roasting, is reported to contain bioactive compounds, including xanthines and polyphenols, showing promising potential for food and nutraceutical applications. This study investigated the beneficial effects of CSS hydroalcoholic extracts, which were chemically characterized by Attenuated Total Reflectance–Fourier-Transform Infrared Spectroscopy and ElectroSpray Ionization tandem Mass Spectrometry, on Caenorhabditis elegans physiology. CSS supplementation improved healthspan-related parameters and delayed aging-associated functional decline, without significantly extending lifespan in wild-type nematodes. Treated worms exhibited a 57% reduction in reactive oxygen species (ROS) levels and upregulation of antioxidant genes (gst-4 and sod-3), suggesting that CSS mitigates oxidative stress through the DAF-2/DAF-16 pathway. Under high-glucose diet conditions, CSS reduced lipid droplet accumulation and modulated the expression of metabolic genes, including upregulation of nhr-49 which is a key regulator of fatty acid oxidation. CSS restored lipid homeostasis and rescued the shortened lifespan of obese nhr-49 mutant worms, suggesting enhanced β-oxidation. Moreover, CSS modulated serotonergic signaling by increasing tph-1 and ser-6 expression, linking its effects to serotonin-mediated regulation of fat metabolism. Finally, CSS promoted the growth of probiotic strains, suggesting potential prebiotic properties. Overall, these findings identify CSS as a metabolic modulator capable of alleviating oxidative and metabolic stress, supporting its sustainable application in the development of functional foods and nutraceuticals.

Microplastics (MPs) are plastic particles smaller than 5 mm that accumulate in ecosystems and can cause toxicity in organisms by affecting multiple biological processes. This study investigates the effects of poly(methyl methacrylate) microplastic microspheres (MPs, 200 µm diameter) on Caenorhabditis elegans, a widely used model in ecotoxicology. Nematodes were exposed to MPs at concentrations of 0.01, 0.1, 1, and 10 mg/mL, and various toxicological endpoints were assessed. The uptake of MPs was evaluated by µFT-IR analysis. The results indicate that MPs induce a concentration-dependent reduction in body length and alterations in the reproduction rate. Lifespan was also significantly reduced, with a 20% decrease at the highest concentration. Intestinal permeability assays revealed disruption of gut integrity at higher concentrations, and oxidative stress analysis showed a 1.8-fold increase in reactive oxygen species (ROS) levels at 10 mg/mL. Gene expression analysis via real-time qPCR indicated the upregulation of genes involved in oxidative stress and in DNA repair mechanisms. Additionally, the longevity-related transcription factors daf-16 and skn-1 were modulated, suggesting an adaptive stress response. These findings suggest that MPs impair growth, reproduction, and oxidative stress response in C. elegans, emphasizing the potential risks associated with microplastic exposure.

Biodeterioration represents a major threat to cultural heritage, as microbial colonization can cause both esthetic and structural damage. The use of conventional chemical biocides raises concerns due to environmental and health risks, potential substrate deterioration, and the emergence of resistant strains. In this study, an ozone-loaded bacterial cellulose (OBC) hydrogel was investigated as an eco-friendly, broad-spectrum antimicrobial treatment in the case study of the Cryptoporticus of the Baths of Trajan (Rome, Italy), a hypogean archeological site where some structures are severely affected by phototrophic biofilms. Microorganisms isolated from a colonized wall were employed in laboratory assays. OBC hydrogel exhibited strong antimicrobial activity, with >90% bacterial mortality within 10 min, complete inhibition of fungal spore germination after 24 h, and a marked reduction in microalgal chlorophyll fluorescence comparable to heat-killed controls. Furthermore, tests on Carrara marble and brick specimens artificially contaminated with microalgae confirmed the removal of green staining, restoring surface chromatic parameters (ΔE* < 5) comparable to those obtained with a commercial biocide. In situ applications demonstrated significant suppression of green biofilm for at least two months. These findings support OBC hydrogel as a sustainable, effective, and non-toxic alternative to conventional biocides for controlling microbial and microalgal colonization on cultural heritage surfaces.