On-demand drug release nanoplatform based on fluorinated aza-BODIPY for imaging-guided chemo-phototherapy.

Intelligent drug delivery systems (DDS), integrating with multi-modal imaging guidance and controlled drug release, have practical significance in enhancing the therapeutic efficiency of tumors. Herein, fluorinated aza-boron-dipyrromethene (NBF) with high near-infrared absorption is synthesized by introducing nonadecafluorodecanoic acid into aza-BODIPY via the amide bond. Through the co-precipitation methods, nanoparticles (NPs) based on NBF are fabricated and the obtained NBF NPs can not only load with DOX with a high loading efficiency (25%, DNBF NPs), but also absorb PFC droplets (1H-perfluoropentane) with bp of 42 °C because of the fluorinated chains inside NBF NPs (PDNBF NPs). Under 808-nm laser irradiation, the hyperthermia effect of NBF could induce the liquid-gas phase transition of PFC droplets, triggering the burst release of DOX and enhancing echo signals for ultrasound imaging as well. With efficient enrichment of PDNBF NPs at tumor site as revealed by in vivo ultrasound imaging and photoacoustic imaging, significant improvement in inhibiting tumor growth is achieved with PDNBF NPs under laser irradiation without noticeable side effects. The work presents a multifunctional organic DDS with great biocompatibility, high drug loading efficiency and light-stimuli-responsive drug release, which provides a new strategy for the manufacture of intelligent composite theranostic nanoplatform.