Amino-grafted mesoporous silica nanoparticles: assessment of neuromodulatory, membranotropic and antioxidant properties in cortex nerve terminals

Aim. In biomedical applications, silica nanoparticles are promising for controlled drug delivery. Also, from an environmental point of view, silica accounts for the most significant part of the mass of air pollution, particularly matter components, especially during sand dust storms. Methods. Amino-grafted mesoporous silica nanoparticles (MSN-NH2) were synthesized by means of co-condensation of tetraethoxysilane and 3-aminopropyltriethoxysilane and characte rized using TEM, SEM, FTIR-spectroscopy, and powder X-ray diffraction. Neuromodulatory and related properties of MSN-NH2 were evaluated using rat cortex nerve terminals (synaptosomes). Results. MSN-NH2 did not influence the extracellular synaptosomal level of excitatory neurotransmitter L-[14C]glutamate and so did not cause excitotoxicity. In fluorescence measurements, MSN-NH2 depolarised the synaptosomal membrane and demonstrated weak antioxidant properties, decreasing the spontaneous generation of reactive oxygen species, whereas MSN-NH2 did not alter H2O2 in nerve terminals. The model of Cd2+/Pb2+/Hg2+-induced excitotoxicity was used to assess the capability of MSN-NH2 to adsorb xenobiotic heavy metals. MSN-NH2 did not modulate the Cd2+/Pb2+/Hg2+-induced increase in the extracellular synaptosomal level of L-[14C]glutamate. Conclusions. MSN-NH2 did not demonstrate excitotoxic signs, had weak antioxidant properties, and was biocompatible. MSN-NH2 did not mitigate the excitotoxic effects of xenobiotic heavy me tals and did not adsorb these metals in biological systems.