amine-functionalized- mesoporous silica nanoparticles by various pore sizes containing gallic acid: characterization and cytotoxicity effect

Mesoporous silica nanoparticles (msns) with varying pore sizes of 2.4, 2.44, and 3.44 nm were synthesized and functionalized using 3-aminopropyltriethoxysilane (ap-msns), followed by the loading of gallic acid (ga) to produce ap-msns-ga. the nanoparticles were characterized through a series of analytical techniques, including fourier transform infrared (ft-ir) spectroscopy, nitrogen adsorption isotherms, thermal gravimetric analysis (tga), transmission electron microscopy (tem), and x-ray diffraction (xrd). the evaluation of the release profile of ga and its antioxidant capacity was conducted at different ph levels. the cytotoxicity of ap-msns-ga with a pore size of 2 nm, along with their ga-loaded counterparts, was evaluated at various concentrations (0 to 500 (µg/ml)) through mtt assays and flow cytometry analyses. an increase in pore size alongside a higher concentration of nh2 groups on the silica nanoparticles surface resulted in a modest enhancement in ga loading efficiency. the synthesized amine-functionalized msns exhibited pore sizes measured at 2 nm, 2.21 nm, and 3.28 nm, with corresponding ga loading percentages of 11%, 11.4 %, and 12 % (w/w) for ga/ap-msns respectively. notably, the release rate of ga demonstrated significant dependence on ph levels. the antioxidant capacity of the released ga remained consistent while exhibiting an increase in strength relative to the quantity released. the results indicated that ap-msns-ga are effective nanocarriers for the delivery of ga in simulated body fluid (sbf), due to low burst release and slower release. furthermore, ap-msns synthesized via the post-synthesis method displayed considerable cytotoxicity at concentrations exceeding 20 µg/ml, which was further amplified upon loading with ga. silica nanoparticles within the nucleus, cytoplasm, and vacuoles were confirmed through transmission electron microscopy (tem) images, indicating a non-specific cellular uptake. additionally, the functionalization of msns exhibited enhanced bioavailability in caco-2 cells.