co-Condensation Synthesis of Salicylaldimine Calcium Complex Containing Mesoporous Silica Nanoparticles as Carriers for Drug Release

A series of functional mesoporous silica nanoparticles(MSNs) was synthesized by a one-step simple synthesis approach involving co-condensation of tetraethoxysilane(TEOS) and salicylaldimine ligand(Sal-Si) in the presence of cetyltrimethylammonium chloride(CTAC) under basic conditions. The target MSNs with different sizes (50, 100 and 200 nm, respectively) were obtained. Furthermore, the Ca²⁺ cations were also introduced into MSNs. The prepared nanoparticles were characterized by means of infrared(IR) spectra, thermogravimetric analysis(TGA), inductively coupled plasma(ICP), CHN elemental analysis, nitrogen adsorption-desorption, scanning electron microscope(SEM) and transmission electron microscope(TEM). Ibuprofen(IBU) which contains carboxyl groups was selected as a model drug. The results of drug loading and release reveal that the loading capacities and release behaviors of the model drug are highly dependent on the Ca²⁺ cations in MSNs. The release of IBU from the MSNs functionalized by Ca²⁺ cations is found to be effectively controlled when compared to the release from the MSNs without the functionalization of Ca²⁺ cations, which is due to the ionic interaction between carboxyl groups in IBU and Ca²⁺ cations in MSNs.