Gentamicin-Loaded Chitosan Nanoparticles Improve Its Therapeutic Effects on Brucella -Infected J774A.1 Murine Cells

Final elimination of some intracellular bacterial agents, such as Brucella, is often a complex issue and impossible to achieve, primarily due to the presence and survival of the bacteria within phagocytic cells. By penetrating into the cell membrane, drug delivery nanosystems can reduce the number of intracellular bacteria. The aim of this study was to assess the efficacy of chitosan nanoparticles on the delivery of gentamicin into infected J774A.1 murine cells in vitro. Chitosan nanoparticles (NPs) were synthesized using ionic gelation technique. The shape, size and charge of NPs, loading rate and release of the drug were investigated. Finally, the effects of gentamicin-loaded chitosan NPs (Gen-Cs) and free gentamicin on J774A.1 murine cells infected with these bacteria were examined. The mean size and charge of NPs were computed as 100 nm and +28mV, respectively. The loading capacity of NPs was 22%. About 70% of the drug was released from NPs during the first 8 hours. Antimicrobial activity of the two formulations showed that MIC (minimum inhibitory concentration) of the Gen-Cs and free drug was 3.1 and 6.25 µg, respectively. The minimum bactericidal concentration of the NPs-loaded drug and free drug was 6.25 and 12.5 µg, respectively. Cell culture analysis revealed that there was a significant reduction in the load of the intercellular bacteria in J774A.1 murine cells in both formulations. Our results showed the Gen-Cs have a proper potential for optimal treatment of intracellular bacterial agents.