Synthesis and characterization of a novel nanocarrier for biocompatible targeting of an antibacterial therapeutic agent with enhanced activity

This study reveals a new strategy to enhance the activity of an antibacterial drug by conjugating it with a Cu–Ag-based nanocarrier. The Cu–Ag–Co3O4–TiO2nanocomposite is successfully synthesized by mechanical alloying and applied for biocompatible targeting of an antibacterial drug by conjugating the drug (10 wt%) with the nanocarrier. The samples have been well-characterized by the Rietveld refinement of the XRD pattern and by analyzing TEM, FESEM images, and FTIR spectra. The successful formation of the drug conjugated nanocomposite sample has also been verified from the EDS and UV–Vis absorption spectra. Both the samples are non-toxic to the normal human cells which have been confirmed by cell viability assay on human normal lung fibroblast WI38 cells. Antibacterial activities of both the samples against the bacteria E. colihave been investigated by the agar cup diffusion method and minimum inhibitory concentration (MIC) study. The 10 wt% amoxicillin conjugated nanocomposite shows the same effect as the pure (100 wt %) drug. The enhanced activity of the drug conjugated nanocomposite is due to the more significant interaction of the drug conjugated nanocomposite with the cell wall and membrane of the bacteria as compared to the pure drug. It is confirmed by measuring the change of conductivity and total protein leakage in the culture filtrate of the nanocomposite, pure drug, and drug conjugated nanocomposite treated culture of Bacillus subtilis. This strategic protocol is found to have great importance for enhancing the efficacy of a standard antibiotic drug.