Polymeric Hydrogels Loaded with ZnO Nanoparticles as Promising Tools for Tacking Viral Skin Disorders

JAIMES, ANA KAREN; AYALA-PEÑA, VICTORIA; BUZZI, AGUSTÍN; ÁLVAREZ, VERA; LASSALLE, VERÓNICA

Viruses

MDPI

Año: 2026 vol. 18 p. 1 - 27

Zinc oxide nanoparticles (ZnO NPs) have attracted growing interest in several fields,including topical biomedical applications, due to their stability, biocompatibility andtherapeutic potential. In this study, chitosan (Ch), gelatin (G) and arabic gum (AG) werecombined to formulate hydrogels loaded with different ZnO NP concentrations. The mainaim is to assess the synergy between the properties of biopolymers and ZnO moieties interms of antiviral activity. ZnO NPs were synthesized via co-precipitation. Hydrogels wereprepared using the freeze–thaw method, and the loading of 2.5, 5 and 7.5% w/w of ZnONPs with respect to Ch was promoted by ultrasonication. The structural, morphological,surface and thermal properties of hydrogels loaded with ZnO NPs (HZ 2.5, HZ 5 andHZ 7.5) and the control matrix (H) were characterized using FTIR spectroscopy, confirmingthe successful incorporation and interaction of ZnO NPs with the polymeric network. LowZnO NP concentrations enhanced the swelling degree of the hydrogels (from 1044% to1253%), improving their thermal stability and solubility (96 h vs. 48 h HZ 7.5 and 14 h in thecase of H). This behavior could be ascribed to the aggregation of ZnO NPs with increasingamounts, which was verified through FESEM. Virucidal activity was tested against herpessimplex virus type 1 (HSV-1) and bovine coronavirus (BCoV), demonstrating a substantialenhancement when the ZnO NPs are added independently of the concentration. An almost100% viral inhibition was recorded when the HZs were analyzed, whereas the H matrixshowed an inhibition of about 40% against the same virus. Antioxidant activity wasevaluated via the DPPH free radical inhibition method, revealing an improvement with theloading of NPs.