Nanostructured Mesoporous Silica-Based Devices for Smart Chemotherapy

Mesoporous silica with its regular nanostructure, good biocompatibility, large surface areas, large void volumes, high homogeneity in the pore diameter, represents an ideal nanoarchitecture to develop nanostructured devices able to interact with biological structures. We have developed (1) a class of hybrid bi/multi-functional Mesoporous Silica Nanoparticles (MSN) that allows the complete engineering of the release of a chemotherapeutic agent. The main limitations of current chemotherapies are poor selectivity for cancer cells and severe toxicity to normal cells that causes the dose responsive effect. Highly aggressive doses are thus necessary to eradicate tumours. Therefore, localized drug delivery would, ideally, improve the therapeutic efficacy, minimizing side effects. In our approach mesoporous silica is functionalized on the external silica surface using a receptor specific ligand that is recognized by cancer cells receptors. An anticancer drug is grafted on the silica surface of the pore walls usually using a pH-sensitive bond. In this way our device is internalized by cancer cells through a receptorspecific mechanism and, in cancer cells organelles, the pH decrease induce the release of the drug.