Impact of Mesoporous Silica Functionalization Fine-Tuning on Antibiotic Uptake/Delivery and Bactericidal Activity

[Image: see text] The mesoporous SBA-15 material was surface-functionalized with amino and carboxylic acid groups and used as a platform to investigate the interaction of these chemical groups with tetracycline, kanamycin, and ampicillin antibiotics. The interactions between the antibiotic and the functionalized surfaces were characterized using two-dimensional (1)H-(13)C HETCOR CP MAS and FTIR spectroscopy and indicated that −COO(–) NH(3)(+) bondings had been formed between chemical groups on the silica surface and drug molecules. The surface modification resulted in higher kanamycin and ampicillin loadings and a slow-release rate, and all synthesized systems showed antibacterial activity against susceptible Escherichia coli bacteria. Almost total death of bacteria was obtained using a few ppm of tetracycline- and kanamycin-loaded systems, whereas the ampicillin-loaded one showed lower bactericidal activity than free ampicillin.