Synergistic antiviral potential of N-(2-hydroxy)propyl-3-trimethylammoniumchitosan-functionalized silver...

This study introduced a novel antiviral approach by combining three substances with different antiviral mechanisms: N-(2-hydroxy)propyl-3-trimethylammoniumchitosan (HTC), silver nanoparticles (AgNPs), and oseltamivir. First, positively surface-charged AgNPs were prepared using an environmentally friendly method. The surfaces of these AgNPs were capped with cationic quaternary chitosan HTC. It exhibits a positive zeta potential with extraordinary stability in aqueous solutions and facilitates substantial and rapid cellular uptake including entry into the cell nucleus. HTC-AgNPs display broad-spectrum antiviral activity against three influenza A viruses (H5N1, H3N2, and H1N1) at biocompatible concentrations. When blended with oseltamivir, HTC-AgNPs enhances the antiviral activity from that of oseltamivir alone by at least 20 times. After 24 h of combined treatment, the inhibition efficiency against influenza A virus can attain up to 99.9 %. We anticipate that this combination could reduce the effective dose of Tamiflu by 10-fold when used in clinic, thus shortening recovery period and lowering the medication costs. Moreover, the synergistic effects of the three active substances would reduce the likelihood of the emergence of drug-resistant viral strains. This would, in turn, enhance the effectiveness and safety of this medication.