Produção e caracterização de membranas bioativas baseadas em quitosana e híbridos de ZnO/Ag OU ZnO/Ag2O

Abstract

The research addresses the global issue of wound management, focusing on the development of effective polymeric membranes with an emphasis on chitosan (CHI), a polysaccharide derived from chitin known for its non-toxicity and antimicrobial activity. The inclusion of glycerol (GLI) as a plasticizer aims to overcome the rigidity of CHI. The study aims to characterize and explore the in vitro biological evaluation of zinc oxide nanoparticles (ZnO NPs) conjugated with silver nanoparticles (Ag NPs) or silver oxide nanoparticles (Ag2O NPs) in CHI membranes, with and without GLI. The sustainable synthesis of ZnO NPs by the starch-mediated sol-gel method, followed by efficient conjugation with Ag or Ag2O NPs through photoreduction and thermal treatment, resulted in successful integration of nanohybrids into CHI/GLI membranes, indicating promising applications. X-ray diffraction (XRD) analysis suggests the phases of nanohybrids and membranes conjugated with nanomaterials, while morphological analyses indicate average diameter sizes of 34 nm for ZnO NPs, 8 nm for Ag NPs, and 6 nm for Ag2O NPs, predominantly exhibiting spherical shapes. The results of water vapor transmission rate (WVTR, gm−2 d −1 ) measurements in CHI membranes (67 ± 1), CHI20 (70 ± 1), CHI20ZnO (66 ± 2), CHI20Ag (78 ± 7), and CHI20Ag2O (72 ± 4) show values similar to commercial dressings. For the nanohybrids, biological assays have revealed biocompatibility activity in J774 macrophage cells. The antidiabetic activity demonstrated inhibition of α-glucosidase and α-amylase enzymes, suggesting beneficial properties in diabetes control. Regarding antioxidant activity, the 2,2-diphenyl-1- picrylhydrazyl (DPPH) free radical method was employed, and the ZnO/Ag2O nanohybrids stand out for their higher antioxidant activity, with an IC50 value of 183.5 µg/mL. Subsequently, the in vitro antimicrobial activity of the nanohybrids and produced membranes was assessed, revealing potential efficacy against both gram-positive and gram-negative strains. Notably, the CHI/GLI/Ag2O membrane samples and the ZnO/Ag2O nanohybrid exhibited larger inhibition zones against the tested strains, respectively. These findings suggest potential assistance in the human skin healing process and highlight their suitability as biomaterials.