Chapter 13: Chemoresponsive Mesoporous Silica Nanoparticles for Targeted Drug Delivery in Cancer Therapy

This chapter reviews the advances developed to date regarding mesoporous silica nanoparticles (MSNPs) as chemoresponsive release systems in targeted cancer therapy. Since MSNPs entered the controlled drug delivery arena in 2001, they have widely been projected as multifunctional nanocarriers for the treatment of complex pathologies, especially cancer. The first challenge to face is providing MSNPs with selective targeting capability, so they can reach, penetrate into and accumulate in the whole tumoral mass and, once there, be specifically internalized by diseased cells. Hence, Section 13.2 of this chapter has been fully updated, including new sections to show the different strategies aimed at (i) promoting passive targeting and providing the nanosystems with “stealth” properties, (ii) incorporating active targeting ligands and (iii) increasing tumour penetration. Section 13.3 describes the different approaches to face the second challenge, i.e. providing MSNPs with chemoresponsive properties, in such a way that the therapeutic cargo(es) can be released upon exposure to endogenous stimuli, namely, pH, enzymes, small molecules or reductive species, either alone or in combination with the so-called multi-responsive nanosystems. To make this section easier to read and understand, for a given stimulus as release trigger, the authors have classified the nanosystems according to the constituent elements. Finally, after 20 years of this exciting scientific journey, the authors envision the future prospects for the transition from bench to bedside.