ANTIBIOTIC LOADED Modified silica nanoparticles

MEBERT ANDREA MATHILDE; ALVAREZ GISELA SOLANGE; CAROLE AIME; HELARY CHRISTOPHE; MOSSER GERVAISE; CORADIN THIBAUD; DESIMONE MARTIN FEDERICO

Rosario

Congreso; Reunión anual SAIB 2014; 2014

In the present study, the antimicrobial activity of antibiotic loaded bare (SiNP) and modified silica nanoparticles was tested. The modifications were carried out with 3-Aminopropyltriethoxysilane (SiNP-NH2), 3-mercaptopropyltrimethoxysilane (SiNP-SH) and a third modification was achieved by oxidizing the last ones (SiNP-SO3-). As examples of antibiotic gentamicin sulfate and sodium rifamycin were used. The antimicrobial activity was tested performing the susceptibility disk diffusion test on LB agar. Pseudomonas aeruginosa, a gram negative, and Staphylococcus aureus, a gram positive, were used as model microorganisms. It was observed that the loading capacity of gentamicin sulfate was higher in the sulfonate modified nanoparticles (SiNP-SO3-) and the unmodified nanoparticles (SiNP). This is indicative that electrostatic interactions are involved in the loading of this antibiotic; these NPs are negatively charged at the working pH while the drug has a positive charge. Regarding rifamycin, which is negatively charged, the highest loading capacity was found with the thiol (SiNP-SH) rather than with amino modified nanoparticles (SiNP-NH2). The loading of this drug does not seem to involve primarily electrostatic interactions but of a different nature, probably hydrophobic interactions.