Effectiveness of pH on formation and characterization of chitosan-alginate nanoparticles and nanohydrogels based on the formed nanoparticles

Nanohydrogels combine the properties of both hydrogels and nanoparticles (NPs), making them more desirable for sophisticated applications in food and medicine fields. In this study, using different amounts of acetic acid (1–3% V/V) in the chitosan solution with pH value ranging 2.9 to 4, chitosan-alginate (Chi/Alg) NPs were prepared in the colloidal form and using ionotropic gelation method and converted into nanohydrogel by lyophilization technique. results based on TEM indicated that formed spherical NPs had particle size less than 100 m. Results based on XRD, AFM, FE-SEM and FTIR indicated that using 2% (V/V) acetic acid, Chi/Alg nanohydrogel with more desirable physico-chemical properties, including semi-crystalline state, degradation (0%), and maximum antioxidant activity (8.1%), porosity (519%) and swelling (53.4%) was fabricated. Furthermore, released polyelectrolytes from this formed nanohydrogel had minimum particle size (2 nm) and polydispersity index (0.602), and relative high zeta potential (− 14.25 mV) value. Results also revealed that this prepared nanohydrogel had high antimicrobial activity toward Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli Salmonella enteritidis and Saccharomyces cerevisiae with clear zone diameter of 20, 15, 13, 19 and 26 mm, respectively. developed method in Chi/Alg nanohydrogel preparation can decrease its potential applications in delivery food bioactive compounds for production of new food products and formulations.