Synthesis and characterization of hydrogels based on maltodextrins with antimicrobial properties

Abstract

In this work, hydrogels with antimicrobial activity based on the polysaccharide maltodextrin (MD) were prepared by copolymerization with either acrylic acid (AAc) or acrylamide (AAm) to endow chemical functionality to host zinc oxide nanoparticles (ZnO). MD was previously modified with glycidyl methacrylate (GMA) in order to be susceptible to react with these monomers through free radical polymerization. The weight ratio of MD to the respective monomer was tuned in order to know its effect on the formation of a hydrogel. The preparation of these hydrogels was confirmed by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). Swelling studies showed a better capacity to swell water for the polyacrylamide (PAAm)-containing hydrogels than those with polyacrylic acid (PAAc). These results were confirmed by the scanning electron microscopy (SEM) studies where the PAAm-containing hydrogels showed a 3D porous structure morphology with a bigger pore size than the PAAc-containing hydrogels. In addition, the energy-dispersive X-ray spectroscopy (EDX) demonstrated the presence of ZnO in the prepared hydrogels. ZnO-loaded hydrogels showed antimicrobial activity against Escherichia coli and Staphylococcus aureus. These results suggest that these hydrogels could be used in the biomedical area particularly as wound dressings due to their antimicrobial and swelling properties.