Chitosan/heparin blends in ionic liquid produce polyelectrolyte complexes that quickly adsorb citrate-capped silver nanoparticles, forming bactericidal composites

摘要

We present chitosan (CHT)/heparin (HP) polyelectrolyte complexes (PECs) that quickly adsorb citrate-capped silver nanoparticles (AgNPs). CHT/HP blends in ionic liquid ([HMIm][HSO4]) form durable PECs after precipitation in water. CHT/HP PECs have positive Zeta potentials (higher than +20 mV). They adsorb citrate-capped AgNPs (Zeta potential of - 12.25 mV) synthesized from Turkevich's method. PEC/AgNPs composites are characterized by spectroscopic, thermal, and microscopy analyses. AgNPs on the PEC surfaces are confirmed by transmission electron microscopy. PECs adsorb AgNPs from aqueous suspensions, achieving approximate to 95% of removal (17.18 mu g of AgNPs per milligram of PEC) after only 10 min. The pseudo-second-order kinetic model adjusted well to the experimental data. The PECs release approximately 11.80 mu g/mg Ag+ (66%) compared to the initial adsorbed AgNPs content (17.18 mu g/mg) after 7200 min at pH 2.0. The PECs present low swelling degrees (between 130 and 150%), supporting high stability in water. PEC/AgNPs composites promote significant bactericidal activity toward Staphylococcus aureus and Escherichia coli between 0.25 and 0.5 mg/mL. This study shows a new strategy to create hybrid polysaccharide/AgNPs composites. PECs can stabilize the AgNPs and release Ag+ ions, supporting antimicrobial materials. (C) 2021 Elsevier B.V. All rights reserved.