Zoledronate and SPIO dual-targeting nanoparticles loaded with ICG for photothermal therapy of breast cancer tibial metastasis

Currently, nanoparticles (NPs) for cancer photothermal therapy (PTT) have limited in vivo clearance, lack targeting ability and have unsatisfactory therapeutic efficiency. Herein, we report a dual-targeting and photothermally triggered nanotherapeutic system based on superparamagnetic iron oxide (Fe(3)O(4)) and indocyanine green (ICG)-entrapped poly-lactide-co-glycolide modified by ZOL (PLGA-ZOL) NPs (ICG/Fe(3)O(4)@PLGA-ZOL) for PTT of breast cancer tibial metastasis, which occurs frequently in the clinic and causes challenging complications in breast cancer. In this system, both ICG and Fe(3)O(4) can convert light into heat, while NPs with Fe(3)O(4) and ZOL can be attracted to a specific location in bone under an external magnetic field. Specifically, the dual-targeting and double photothermal agents guaranteed high accumulation in the tibia and perfect PTT efficiency. Furthermore, the in vivo studies showed that ICG/Fe(3)O(4)@PLGA-ZOL NPs have extraordinary antitumor therapeutic effects and that these NPs can be accurately located in the medullary cavity of the tibia to solve problems with deep lesions, such as breast cancer tibial metastasis, showing great potential for cancer theranostics.