Due to the different antibacterial mechanisms of Ag and TiO2 nanoparticles (NPs), and their unique physicochemical characteristics, combination of these two components in a single nanoplatform provides a multifunctional nanohybrid possessing synergistic effectiveness for a broader range of bacteria, especially for those which are resistant to common antibacterial drugs. For this reason, the TiO2-Ag nanohybrids have attracted a growing interest in recent years and there have been admirable efforts to develop their synthesis methods, structural properties, and applications [1]. Although there are acceptable conjugation methods, it still requires more studies to develop effective strategies to synthesize stable nanohybrids for the biological applications. One of the promising conjugation methods is to employ biocompatible siloxanes to mediate the conjugation of TiO2 with Ag nanoparticles keeping these nanocomponents stable in aqueous media. In this research, (3-mercaptopropyl)trimethoxysilane (3MPTMS) was used as a bifunctional linker bearing soft –SH and hard –O parts in its opposing sites of structure for the chemical conjugation of Ag to TiO2NPs. More importantly, this chemical coupling agent improves the biochemical properties of the resultant TiO2-Ag nanoconjugate. In brief, commercially available TiO2NPs with a size range of 10-35 nm were firstly modified with 3MPTS (hydrolyzed form of 3MPTMS) with a sol-gel method through the condensation of titania –OH groups with the –OH moiety of the silane linker. Then hydrophilic AgNPs-3MPS (3MPS: 3-mercapto1-propanesulfonate) were prepared in situ and directly attached to the free –SH groups of TiO2-3MPTS surface to form the final TiO2@3MPTS-Ag@3MPS nanohybrid. For the preparation of both TiO2@3MPTS and TiO2@3MPTS-Ag@3MPS, different reaction conditions were studied. The stability, size, morphology, and chemical composition of TiO2@3MPTS and the nanohybrid were evaluated by UV-Vis, FT-IR, SEM-EDS, DLS, 1H-NMR, and XPS characterizations. Thanks to multidisciplinary collaborations, the antibacterial studies of TiO2@3MPTS and TiO2@3MPTS-Ag@3MPS are in progress. [1] J. Z. Soo, L. Ching Chai, B. Chin Ang, B. Hoong Ong, ACS Appl. Nano Mater. 2020, 3, 5743.
Chemical conjugation of highly stable Ag nanoparticles with silane-functionalized TiO2 nanoparticles for potential dual antibacterial effect / HAJAREH HAGHIGHI, Farid; Mercurio, Martina; Cerra, Sara; Salamone, Tommaso A.; Marsotto, Martina; Battocchio, Chiara; Fratoddi, Ilaria. - (2022). (Intervento presentato al convegno The workshop "Novel frontiers in nanocarriers preparation and characterization" tenutosi a Rome, Italy).
Chemical conjugation of highly stable Ag nanoparticles with silane-functionalized TiO2 nanoparticles for potential dual antibacterial effect
Farid Hajareh Haghighi;Martina Mercurio;Sara Cerra;Tommaso A. Salamone;Ilaria Fratoddi
2022
Abstract
Due to the different antibacterial mechanisms of Ag and TiO2 nanoparticles (NPs), and their unique physicochemical characteristics, combination of these two components in a single nanoplatform provides a multifunctional nanohybrid possessing synergistic effectiveness for a broader range of bacteria, especially for those which are resistant to common antibacterial drugs. For this reason, the TiO2-Ag nanohybrids have attracted a growing interest in recent years and there have been admirable efforts to develop their synthesis methods, structural properties, and applications [1]. Although there are acceptable conjugation methods, it still requires more studies to develop effective strategies to synthesize stable nanohybrids for the biological applications. One of the promising conjugation methods is to employ biocompatible siloxanes to mediate the conjugation of TiO2 with Ag nanoparticles keeping these nanocomponents stable in aqueous media. In this research, (3-mercaptopropyl)trimethoxysilane (3MPTMS) was used as a bifunctional linker bearing soft –SH and hard –O parts in its opposing sites of structure for the chemical conjugation of Ag to TiO2NPs. More importantly, this chemical coupling agent improves the biochemical properties of the resultant TiO2-Ag nanoconjugate. In brief, commercially available TiO2NPs with a size range of 10-35 nm were firstly modified with 3MPTS (hydrolyzed form of 3MPTMS) with a sol-gel method through the condensation of titania –OH groups with the –OH moiety of the silane linker. Then hydrophilic AgNPs-3MPS (3MPS: 3-mercapto1-propanesulfonate) were prepared in situ and directly attached to the free –SH groups of TiO2-3MPTS surface to form the final TiO2@3MPTS-Ag@3MPS nanohybrid. For the preparation of both TiO2@3MPTS and TiO2@3MPTS-Ag@3MPS, different reaction conditions were studied. The stability, size, morphology, and chemical composition of TiO2@3MPTS and the nanohybrid were evaluated by UV-Vis, FT-IR, SEM-EDS, DLS, 1H-NMR, and XPS characterizations. Thanks to multidisciplinary collaborations, the antibacterial studies of TiO2@3MPTS and TiO2@3MPTS-Ag@3MPS are in progress. [1] J. Z. Soo, L. Ching Chai, B. Chin Ang, B. Hoong Ong, ACS Appl. Nano Mater. 2020, 3, 5743.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.