Alginate derivative-functionalized silica nanoparticles: surface modification and characterization

Abstract

The bare silica nanoparticles (SiO2 NPs) synthesized by Stober method is very hydrophilic and chemically inert, which may suffer from particles aggregation and low biocompatibility when they are used in physiological media. For this case, we attempted to conduct surface functionalization of SiO2 NPs by Ugi multicomponent reaction, using amphiphilic amidic alginate derivative (AAD) as the modifier. The successful synthesis of amidic alginate derivative-functionalized silica nanoparticles (AAD-SiO2 NPs) was confirmed by FT-IR spectroscopy, 1H NMR spectrometer, X-ray photoelectron spectroscopy and thermal gravimetric analysis. The covalent bonding of alginate derivative onto the surface of SiO2 NPs increased their average diameter and zeta potential, which effectively improved their colloidal stability in PBS. Additionally, surface tension measurements and cell studies results revealed that the resultant AAD-SiO2 NPs possessed relatively high surface activity and cytocompatibility, which exhibited great potential in the biomedical field.