Hybrid Mesoporous Silica for Drug Targeting

The major limitation of traditional chemotherapeutic agents is their poor selectivity for cancer cells and their severe toxicity to normal cells.Therefore, localized drug delivery would, ideally, improve the therapeutic efficacy, minimizing side effects. The properties of mesoporous silica nanoparticles (MSNs) seem to cope with this aim. MCM-41 type MSNs were synthesized using a PEG surfactant-based interfacial synthesis procedure, and successively graft ed with folic acid (FOL), a small molecule used as targeting function, being the natural ligand for the folate receptor (FR). In fact, folate-bound nanoparticles (MSNFOL), loaded with an antineoplastic drug, are exclusively internalized by cancer cells overexpressing FR (FR+ cells) through a highly specific, receptor-mediated, endocytotic process, while not-functionalized MSNs show the unique feature of being not internalized by cells. Moreover, once MSN-FOL reach the cytoplasm of FR+ tumor cells, the antineoplastic drug is released, causing cell death. Thus, such a conceived device could represent a promising tool for targeted chemotherapy on FR+ tumors.