Thermosensitive and tum or microenvironment activated nanotheranostics for the chemodynamic/photothermal therapy of colorectal tumor

This research proposes the one-pot preparation of polydopamine (PDA) decorated mesoporous   silica nanoparticle (PMSN) for the thermal and tumor micro-environment (TME) responsive colorectal tumor therapy. The pores of PMSN were used for the Fe 3+ loading. Lauric acid (LA), a phase-change ligand, was selected as a “doorkeeper” to coat the surface of Fe 3+ -loaded PMSN and prevent the undesired leakage of Fe 3+ . Bovine serum albumin (BSA) was selected as a stabilizer to endow the PMSN-Fe-LA-BSA nanopartilces (PMFLB) with colloidal stability. Under the near infrared laser , the light-sensitive PDA produced significant heat to kill the colorectal cancer cells via hyperthermia. Moreover, the heat induced the phase-change of LA and triggered the release of Fe 3+ , which further reacted with the endogenous H 2 S in the colorectal TME. After that, the Fe 3+ was transformed into Fe 2+ , which triggered the Fenton reaction with the H 2 O 2 in the TME and effectively generated hydroxyl radical (·OH). Finally, the Fe 2+ was transformed into Fe 3+ , which repeatedly reacted with the H 2 S and produced more ·OH to enhance the chemodynamic therapy of colorectal tumor. Such a thermosensitive PMFLB which operates in synergy with the colorectal TME opens an alternative avenue for the rational design of multifunctional nano-therapeutic agents.