Honeycomb-like porous silica nanoparticles for photo and chemo combination therapy

Spherical silica carriers have attracted great interest in drug delivery and tumor therapy, but the preparation of non-spherical mesoporous silica carriers with controlled morphology and pores is still a challenge. Here, honeycomb-like mesoporous silica (HMS) nanorods (NRs) were designed and prepared by etching silica nanorods with phosphate buffer solution (PBS). HMS sample possesses an average diameter of 150 nm and length of 450 nm. Their intricate cavities and high specific surface area (724.2 m 2 g -1 ) would provide good prerequisites for drug adsorption and cellular uptake. HMS carriers have an excellent loading capacity of 43% for doxorubicin hydrochloride (DOX). DOX was loaded into the pores of HMS NRs by electrostatic interaction, followed by introducing indocyanine green (ICG) and melting menthol (LM). ICG is used as photosensitizer and LM acts thermal responsive gatekeeper to block the loaded DOX and ICG. Hyaluronic acid (HA) was grafted onto the surface of HMS carriers to achieve targeting effect and responsive drug release under specific environment. The entrapped LM and HA layer could allow the HMS carrier thermal/enzyme/pH responsive release behavior. ICG can produce singlet oxygen and convert light into local heat under laser irradiation. The DOX/ICG-loaded HMS carrier exhibits triple-responsive characters and displays photochemical combination therapy in vitro.