Synthesis, characterization and modification of Gum Arabic microgels for hemocompatibility and antimicrobial studies

Gum Arabic (GA) microgels were successfully prepared via reverse micellization method with high yield (78.5 ± 5.0%) in 5-100 μm size range using divinyl sulfone (DVS) as a crosslinker. The GA microgels were degraded hydrolytically 22.8 ± 3.5% at pH 1 in 20 days, whereas no degradation was observed at pH 7.4 and pH 9 at 37 °C. By using diethylenetriamine (DETA), and taurine (TA) as chemical modifying agents, GA microgels were chemically modified as GA-DETA and GA-TA, and the zeta potential values of 5.2 ± 4.1 and −24.8 ± 1.3 mV were measured, respectively in comparison to −27.3 ± 4.2 mV for GA. Moreover, blood compatibility of GA, GA-TA, and GA-DETA microgels was tested via in vitro protein adsorption, % hemolysis ratio, and blood clotting index. All the microgels were hemocompatible with% hemolysis ratio between 0.23 to 2.05, and the GA microgels were found to be highly compatible with a blood clotting index of 81 ± 40. The biocompatibility of GA, GA-DETA and GA-Taurine microgels against L929 fibroblast cells also revealed 84.4, 89.1, and 67.0% cell viability, respectively, at 25.0 μg/mL concentration, suggesting great potential in vivo biomedical applications up to this concentration. In addition, 5 and 10 mg/mL minimum inhibition concentrations of protonated GA-DETA microgels (GA-DETA-HCl) were determined against E. coli and S. aureus, respectively.