Funcionalization of silver nanoparticles with beta-lactam antibiotics: an alternative to bacterial resistance

Abstract

The project here described aims to synthesize silver nanoparticles (AgNP) encapsulated into mesoporous silica (MS) for further functionalization with beta-lactams antibiotics. Three different beta-lactams agents will be tested: penicillin G, amoxicillin and ampicillin. Since AgNPs are effective antibacterial agents, the main propose of this work is to obtain a dual bacterial inhibition system, containing AgNPs and beta-lactams agents. Moreover, this work will focus on: (1) analyzing the possible synergism of using AgNPs combined with beta-lactams antibiotics against non-resistant bacteria and (2) investigating a possible bactericidal action of the synthesized systems against beta-lactams resistant bacterias. The structures formed will be characterized by ultraviolet visible spectroscopy (UV-Vis), small angle X-ray scattering (SAXS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA). For those structures containing mesoporous silica, nitrogen adsorption/desorption isotherms will be used in determining the size and organization of the pores. The evolution of the nanoparticles functionalization will be investigated by Fourier transform infrared spectroscopy (FT-IR) and zeta potential. Biological activity experiments will be conducted with Escherichia coli (gram negative), Staphylococcus aureus, Staphylococcus epidermidis and Micrococcus lysodeikticus (gram positive), using the disk diffusion method. Finally, the minimum inhibitory concentration for each system will be determined by nanoparticles incubation test in tubes containing the bacteria.