RESUMO
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 1H-13C HETCOR CP MAS and FTIR spectroscopy and indicated that -COO- NH3 + 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.
RESUMO
Aim: Polyether pores were designed and tetracycline-loaded mesoporous silica materials, with their surface decorated by silver ions, were prepared, with the aim of reaching high antibacterial activity. Meanwhile, mammalian cell cytotoxicity and hemolytic effects were not observed using material concentrations tenfold the ones optimized for the bactericidal tests. Methods: Pore size was tuned by changing the polyether content and the surface was covalently decorated with silver thiolate groups. Results: We showed that the biological activity was enhanced by modulating silver ions and tetracycline releases by tuning silver thiolate group concentration on the silica surface and/or by modulating the pH of the environment. Conclusion: The combined use of tetracycline and silver ions with the mesoporous drug-delivery carrier was a very effective strategy against susceptible and tetracycline-resistant Escherichia coli bacteria.
RESUMO
The selective action of drugs in tumor cells is a major problem in cancer therapy. Most chemotherapy drugs act nonspecifically and damage both cancer and healthy cells causing various side effects. In this study, the preparation of a selective drug delivery system, which is able to act as a carrier for hydrophobic and anticancer drugs is reported. Amino-functionalized silica nanoparticles loaded with curcumin were successfully synthesized via sol-gel approach and duly characterized. Thereafter, the targeting ligand, folate, was covalently attached to amino groups of nanoparticle surface through amide bond formation. The cytotoxic effect of nanoparticles on prostate cancer cells line was evaluated and compared to normal cells line (prostate epithelial cell). Cytotoxicity experiments demonstrated that folate-functionalized nanoparticles were significantly cytotoxic to tumor cells, whereas normal cells were much less affected by the presence of these structures.