Surface modified mesoporous silica nanoparticles as sustained-release gallic acid nano-carriers

Gallic acid (GA) is a natural and non-enzymatic antioxidant with known anticancer property. In the present work, two types of mesoporous silica nanoparticles (MSNs) were evaluated as a nano carrier for sustained release of GA. For this purpose, amine-functionalized (AP-MSNs) and chitosan coated (CS-MSNs) MSNs were synthesized, loaded by GA and then characterized by SEM, XRD, N2 adsorption isotherms and zeta-potential analysis. Optimum conditions for the loading of GA into the modified MSNs were obtained, and then in vitro GA release in simulated gastric fluid (SGF, pHs 1.4) was investigated. Cytotoxicity and cellular uptake of the modified MSNs were also investigated using MCF-7 cells. The encapsulation efficiency and loading capacity were measured 20.77% and 47.06% for AP-MSNs, respectively; while for CS-MSNs, they were obtained as 38.14% and 58.67%, respectively. Results showed that the rate of GA release from CS-MSNs was clearly slower than that from AP-MSNs. Moreover, according to the results, no cytotoxicity effects were observed in both AP-MSNs and CS-MSNs while CS-MSNs showed better killing potency against the MCF-7 cells. The cellular uptake of GA loaded CS-MSNs was also studied by TEM analysis and results showed their high biocompatibility and bioavailability.