Co‐delivery of Doxycycline, Florfenicol and Silver Nanoparticles using Alginate/Chitosan Nanocarriers

The overuse of antibiotics has led to the sharp increase of antibiotic-resistant bacteria that can consequently transmit and cause hard-to-cure human diseases. To deal with this problem, nano drug delivery systems have been widely researched. This report focuses on developing an Alginate/Chitosan-based nanosystem that carried simultaneously Doxycycline (DOX), Florfenicol (FLO), and silver nanoparticles (AgNPs). The optimal Alginate/Chitosan ratio of 3 : 2 (w/w) created the most stable nanocarrier system. The fabricated DOX-FLO@AgNPs had a spherical shape with a small size of about 20 nm and could release slowly DOX and FLO at pH of 7.4 and 5.0. In vitro drug release kinetics of DOX and FLO from DOX-FLO@AgNPs fitted best to the Weibull or Higuchi model by the mechanism of the Fickian or non-Fickian diffusion. The nanosystem of DOX-FLO@AgNPs had much lower IC50 of 0.012 +/- 0.001 and 0.08 +/- 0.005 mu g/mL against E.coli and B.subtilis, respectively, than the conventional form. The FIC50 value of smaller than 0.5 mu g/mL for 5 out of 6 tested bacteria also indicated the synergistic effect of each component in this antibiotic combination. Moreover, the cytotoxicity assay confirmed the viability of 96.4 +/- 2.3 % for vero cell line that exposured to the treatment dose. Therefore, these findings strongly suggest that the DOX-FLO@AgNPs formulation is promising for combined antibiotic drug delivery and silver nanoparticles, and will be worth investigating for further in vivo potential.