Agar and Chitosan Hydrogels’ Design for Metal-Uptaking Treatments
Author:
Cuvillier Luana12ORCID, Passaretti Arianna12ORCID, Guilminot Elodie3ORCID, Joseph Edith2ORCID
Affiliation:
1. Laboratory of Technologies for Heritage Materials, University of Neuchâtel, Bellevaux 51, 2000 Neuchâtel, Switzerland 2. Haute Ecole Arc Conservation Restauration, University of Applied Sciences and Arts Western Switzerland HES-SO, Espace de l’Europe 11, 2000 Neuchâtel, Switzerland 3. Arc’Antique Conservation and Research Laboratory, 26 Rue de la Haute Forêt, 44300 Nantes, France
Abstract
In the field of cultural heritage, the use of natural gels is rising for the application of active agents. Here, two natural polymers are assessed: agar, a pioneer hydrogel for conservation treatments, and chitosan, a rather novel and metal-binding gel. For chitosan, a state-of-the-art based formulation (CS–ItA–LCys) is evaluated as it was reported for silver-complexing properties. It is evaluated whether these polymers can withstand the addition of the chelating compound deferoxamine, which is a bacterial siderophore. This allows for the obtainment of completely bio-sourced gel systems. A Fourier-transformed (FT) infrared spectroscopy characterization is performed, completed with rheological measurements and Cryo-Scanning Electron Microscopy (cryo–SEM) to investigate the physico–chemical properties of the gels, as well as their interaction with deferoxamine. Both polymers are also tested for their inherent complexing ability on silver ions using FT–Raman spectroscopy. A multi-analytical comparison shows different microstructures, in particular, the presence of a thick membrane for chitosan and different mechanical behaviors, with agar being more brittle. Neither hydrogel seems affected by the addition of deferoxamine; this is shown by similar rheological behavior and molecular structures in the presence or absence of the chelator. The intrinsic abilities of the chitosan formulation to make silver complex are demonstrated with the observation of two peaks characteristic of Ag–S and Ag–O bonds. Agar and chitosan are both proven to be reliable gels to act as carriers for bio-based active agents. This paper confirms the potential asset of the chitosan formulation CS–ItA–LCys as a promising gel for the complexation of soluble silver.
Funder
Swiss National Science Foundation
Subject
Polymers and Plastics,Organic Chemistry,Biomaterials,Bioengineering
Reference96 articles.
1. Angelova, L.V., Ormsby, B., Townsend, J.H., and Wolbers, R. (2017, January 16–18). Removing Iron Stains from Wood and Textile Objects: Assessing Gelled Siderophores as Novel Green Chelators. Proceedings of the Gels in the Conservation of Artconservation, London, UK. 2. The Treatment of Iron-Stained Marble: Toward a “Green” Solution;Macchia;Int. J. Conserv. Sci.,2016 3. Sansonetti, A., Bertasa, M., Corti, C., Rampazzi, L., Monticelli, D., Scalarone, D., Sassella, A., and Canevali, C. (2021). Optimization of Copper Stain Removal from Marble through the Formation of Cu(II) Complexes in Agar Gels. Gels, 7. 4. Biological Oxidation of Iron Sulfides;Gadd;Advances in Applied Microbiology,2019 5. Joseph, E., James, S., Albelda-Berenguer, M., Albini, M., Comensoli, L., Cornet, E., Domon Beuret, E., Kooli, W., Brambilla, L., and Mathys, L. (2021, January 17–21). Ground-Breaking Approaches for a Green and Sustainable Metal Conservation. Proceedings of the 19th ICOM-CC Triennial Conference Transcending Boundaries: Integrated Approaches to Conservation, Beijing, China.
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