A"donor–acceptor"structured semiconductor polymer for near infrared fluorescence imaging guided photodynamic therapy

Near infrared(NIR)fluorescence imaging guided photodynamic therapy(PDT)is a technique which has been developed in many clinical trials due to its advantage of real-time optical monitoring,specific spatiotemporal selectivity,and minimal invasiveness.For this,photosensitizers with NIR fluorescence emission and high^(1)O_(2)generation quantum yield are highly desirable.Herein,we designed and synthesized a"donor-acceptor"(D-A)structured semiconductor polymer(SP),which was then wrapped with an amphiphilic compound(Pluronic■F127)to prepare water-soluble nanoparticles(F-SP NPs).The obtained F-SP NPs exhibit good water solubility,excellent particle size stability,strong absorbance at deep red region,and strong NIR fluorescent emission characteristics.The maximal mass extinction coe±cient and fluorescence quantum yield of these F-SPs were calculated to be 21.7 L/(g·cm)and 6.5%,respectively.Moreover,the^(1)O_(2)quantum yield of 89%for F-SP NPs has been achieved under 635 nm laser irradiation,which is higher than Methylene Blue,Ce6,and PpIX.The outstanding properties of these F-SP NPs originate from their unique D-A molecular characteristic.This work should help guide the design of novel semiconductor polymer for NIR fluorescent imaging guided PDT applications.

Folate-targeted co-delivery polymersomes for efficient photo-chemo-antiangiogenic therapy against breast cancer and in vivo evaluation via OCTA/NIRF dual-modal imaging

Intelligent nanoplatform that combines multimodal imaging and therapeutic effects holds great promise for precise and efficient cancer therapy.Herein,folate-targeted polymersomes with stimuli-responsiveness were fabricated and evaluated by near-infrared fluorescence(NIRF)and optical coherence tomography angiography(OCTA)dual-imaging for photo-chemo-antiangiogenic therapy against cancer.The folate-targeted polymersomes(FA-MIT-SIPS)not only integrated ammonium bicarbonate(ABC)and mitoxantrone(MIT)into their hydrophilic cavity but also encapsulated indocyanine green(ICG)and sorafenib(SOR)within their hydrophobic layer.NIRF imaging demonstrated that FA-MIT-SIPS effectively accumulated and retained in the tumors.Upon 808 nm laser irradiation,the ICG produced hyperthermia and reactive oxygen species(ROS)for efficient photothermal and photodynamic therapy.In addition,the decomposition of ABC in responsive to acidic tumor environment and ICG-induced hyperthermia accelerated drug release.The released MIT accumulated in nucleus to inhibit DNA synthesis,while the released SOR destructed tumor vascularization.Notably,OCTA imaging was applied to observe the tumor blood flow upon the combination therapy,demonstrating that FA-MIT-SIPS obviously decreased the vessels area density.Moreover,the synergistic photo-chemo-antiangiogenic therapy of FA-MIT-SIPS achieved excellent antitumor effect with 40%of the 4T1 tumor-bearing mice being completely cured without recurrence.The multifunctional polymersomes provide a promising dual-modal imaging-evaluated synergistic strategy for tumor therapy.