Novel xanthan gum hydrogels boosted with crosslinked carboxymethyl chitosan and zinc oxide nanoparticles: synthesis, characterization and biological activity evaluation

Novel series of carboxymethyl chitosan (CMCs)-based hydrogels was prepared using blends of various weight ratios of CMCs and xanthan gum (XG), followed by their crosslinking utilizing trimellitic anhydride isothiocyanate (TAI) in a concentricity relied on the CMCs proportion. The weight ratios of CMCs:XG were 1:3, 1:1, and 3:1, yielding three hydrogels designated by CMCs/XG(1:3), CMCs/XG(1:1), and CMCs/XG(3:1), respectively. For comparing, CL-CMCs was fabricated by crosslinking pure CMCs utilizing TAI. The hydrogels were modified via loading different concentrations of ZnONPs into their matrices, producing CMCs/XG(1:3)/ZnONPs-3%, CMCs/XG(1:3)/ZnONPs-5%, CMCs/XG(3:1)/ZnONPs-3% and CMCs/XG(3:1)/ZnONPs-5%. The chemical, inner, and morphological structures of the hydrogels and their ZnONPs composites were affirmed using the appropriate analytical instruments. Their inhibition performance against the microbes and biofilms was ordered as: CMCs/XG(3:1)/ZnONPs-5% > CMCs/XG(3:1)/ZnONPs-3% > CMCs/XG(1:3)/ZnONPs-5% > CMCs/XG(1:3)/ZnONPs-3% > CL-CMCs > CMCs/XG(3:1) > CMCs/XG(1:1) > CMCs/XG(1:3) > CMCs. While XG doesn't possess an inhibitory performance against the inspected microbes and biofilms. The CMCs/XG(3:1)-ZnONPs-5% was more effective than Amphotericin B and Vancomycin against almost all the inspected microbial strains. It was secure on the normal human cells. So, incorporation of CL-CMCs and ZnONPs with XG in the same formulations substantially boosted the inhibition efficiency of the produced composites against microbes and biofilms.