Multicolor Two-Photon Nanosystem for Multiplexed Intracellular Imaging and Targeted Cancer Therapy.

The novel theranostic nanosystems based on two-photon fluorescence can achieve higher spatial resolution of deep tissue imaging for simultaneous diagnosis and therapy of a variety of cancers. Herein, we have designed and prepared FRET-based two-photon mesoporous silica nanoparticles (MTP-MSNs) for single-excitation multiplexed intracellular imaging and targeted cancer therapy for the first time. This nanosystem includes two constituents, containing (1) multicolor two-photon mesoporous silica nanoparticles and (2) cancer cell-targeting aptamers that act as gatekeepers for MTP-MSNs. After incubation with cancer cells, the Dox-loaded and aptamer-capped MTP-MSNs could be internalized into the cells, opening the pores and releasing the drug. Furthermore, using two-photon multicolor fluorescence, MTP-MSNs could serve as good contrast agents for multicolor two-photon intracellular imaging with increased imaging depth and improved spatial localization of tissue. In sum, these multicolor MTP-MSNs provide a promising system for traceable targeted cancer therapy with further applications in multiplex intracellular imaging and the screening of drug.