Role of mesoporous silica functionalized with boronic acid derivative in targeted delivery of doxorubicin and co-delivery of doxorubicin and resveratrol

Phenylboronic acid derivatives have gained interest due to their ability to reversibly bind to 1,2-diols, such as sialic acid receptors overexpressed by breast cancer cells. In this study, two types of mesoporous silica, MCM-41 and SBA-15, were functionalized with 4-carboxyphenylboronic acid (CPBA) through the amidation reaction, and the resulting materials MCM-CPBA and SBA-CPBA were used as carriers for doxorubicin (Dox) or for co-delivery of doxorubicin and resveratrol. In the case of MCM-CPBA material, all amine groups were involved in the condensation reaction with boronic acid derivative, while in the case of SBA-CPBA, free amine groups remained on the silica surface. Dox release profiles, performed in phosphate buffer solution pH 5.5, showed a faster release kinetics of Dox and a higher cumulative drug release for co-delivery system. Larger pores of SBA-15-type carrier influenced the Dox release profile as the diffusion of drug molecules was favored, a higher cumulative drug release being obtained in the case of SBA-CPBA than for MCM-CPBA. Biological assessment of the developed drug delivery systems demonstrated lower cytotoxicity on BJ fibroblasts than on BT474 breast cancer cells. Evaluation of drug delivery systems by hyperspectral microscopy evidenced a higher internalization rate of Dox when was loaded on functionalized silica carriers compared to the free drug into BT474 cells. The internalization rate of doxorubicin-loaded carrier depended on the type of carrier; a better internalization was observed for cancer cells when were treated with Dox-loaded MCM-CPBA nanoparticles than for Dox-loaded SBA-CPBA that might be attributed to smaller size of MCM-CPBA nanoparticles.