Hexa-BODIPY-cyclotriphosphazene based nanoparticle for NIR fluorescence/photoacoustic dual-modal imaging and photothermal cancer therapy.

Theranostic, which integrates the diagnosis and tumor treatment in tandem, is an emerging strategy in cancer treatment. Here, we report a novel and unique theranostic nanoparticle, HBCP NP, based on hexa-BODIPY cyclophosphazene (HBCP). Due to the unique bulky molecular structure of HBCP, this nanoparticle can simultaneously perform near-infrared (NIR) fluorescence imaging and photoacoustic imaging (PAI). Interestingly, since reactive oxygen species (ROS) generation of HBCP NPs is completely inhibited, 'safe' fluorescence imaging is possible without the risk of cell damage even under laser irradiation. Finally, NIR fluorescence imaging and PAI in 4T1 tumor-bearing mice demonstrated selective accumulation of HBCP NPs at tumor sites. In addition, HBCP NPs exhibited excellent photothermal effects under high-power laser irradiation, achieving effective tumor growth inhibition. [Display omitted] • A theranostic nanoparticle based on Hexa-BODIPY Cyclophosphazene (HBCP NP) was reported. • HBCP NPs perform simultaneous near-infrared (NIR) fluorescence imaging and photoacoustic (PA) imaging. • HBCP NPs generate almost no ROS even under low-power lasers, which enables 'safe' fluorescence imaging and phototherapy. • The ∼93 nm size of HBCP NPs allows selective accumulation in tumors through the EPR effect. • HBCP NPs effectively inhibited tumor growth with excellent photothermal properties in tumor-bearing mice. [ABSTRACT FROM AUTHOR]