Development of gentamicin-gold nanospheres for antimicrobial drug delivery to Staphylococcal infected foci

Even though the therapeutic efficacy of numerous antimicrobial drugs has been well established, inefficient delivery can result in an inadequate therapeutic index. Gold nanoparticles have unique physicochemical properties such as large surface area to mass ratio and functionalizable structure. These properties can be applied to facilitate the administration of antimicrobial drugs, thereby overcoming some of the limitations in traditional antimicrobial therapeutics. In this study, gold nanospheres were used as a drug carrier system for gentamicin delivery to Staphylococcal infected foci. Conjugation of gentamicin with gold nanospheres was performed in HEPES buffer. The attachment of gentamicin to gold nanospheres was confirmed by UV/Vis spectroscopy. The HPLC and atomic absorption spectrometer analyses showed that 347 gentamicin molecules were attached to each gold nanosphere. Minimum inhibitory concentration and minimum bactericidal concentration studies showed the enhanced antibacterial effect of gentamicin-gold nanospheres complex in comparison with free gentamicin. The biodistribution study showed the localization of the complex at the site of Staphylococcal infection foci with high sensitivity in mouse model.