Synthesis of antibiotic-modified silica nanoparticles and their use as a controlled drug release system with antibacterial properties

In this study, monodispersed silica nanoparticles were synthesized using the Stöber method. The synthesized nanoparticles underwent a range of surface modifications and were converted to nanoparticles with drug release and antibacterial features. For modification, firstly –NH2 groups were created on the silica nanoparticle surface using (3-Aminopropyl)triethoxysilane (APTES). In the second stage, hexachlorocyclotriphosphazene (Phz) molecules were bound to the silica nanoparticle surfaces due to these amino groups. In the final stage of modification, the chloride groups in the hexachlorocyclotriphosphazene structure were modified with trimethoprim (TMP) and nanoparticles with antibacterial properties were obtained. The modified silica nanoparticles were characterized with scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), and Thermogravimetric analysis (TGA). The silica-based nanoparticles were used for release of rhodamine 6G, chosen as a model drug. As a result of the drug release studies, the modified silica nanoparticles were found to abide by the Korsmeyer–Peppas low power model and non-Fickian release mechanism as release model. Additionally, nanoparticles both loaded and not loaded with the model drug were determined to have antibacterial properties against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus bacteria.