Dual stimuli-activatable versatile nanoplatform for photodynamic therapy and chemotherapy of triple-negative breast cancer

Photodynamic therapy(PDT)has emerged as an efficient cancer treatment method with minimal invasiveness.However,the majority of current photosensitizers(PSs)display severe dark toxicity and low tumor specificity due to their"always-on"photoactivity in blood circulation.To address this concern,we herein report a series of acid-activatable PSs for ultrasensitive PDT of triple-negative breast tumors.These set of novel PSs are synthesized by covalently modifying tetrakis(4-carboxyphenyl)porphyrin(TCPP)with a variety of tertiary amines for acidity-activatable fluorescence imaging and reactive oxygen species(RoS)generation.The resultant TCPP derivatives are grafted with a poly(ethylene glycol)(PEG)chain via a matrix metalloproteinase-2(MMP-2)-liable peptide spacer and chelated with Mn^(2+)for magnetic resonance imaging(MRI)capability.The PEGylated TCPP derivatives are amphiphilic and self-assemble into micellar nanoparticles to elongate blood circulation and for tumor-specific PDT.We further demonstrate that the PEGylated TCPP nanoparticles could serve as a nanoplatform to deliver the anticancer drug doxorubicin(DOX)and perform fluorescence image-guided combinatorial PDT and chemotherapy,which efficiently suppress the growth of 4T1 breast tumors and lung metastases in a mouse model.These acid-activatable PS-incorporated nanoparticles might provide a versatile platform for precise PDT and combinatorial breast cancer therapy.

Dual-targeting prodrug nanotheranostics for NIR-Ⅱfluorescence imaging-guided photo-immunotherapy of glioblastoma

Glioblastoma(GBM) therapy is severely impaired by the blood-brain barrier(BBB) and invasive tumor growth in the central nervous system.To improve GBM therapy,we herein presented a dual-targeting nanotheranostic for second near-infrared(NIR-Ⅱ) fluorescence imaging-guided photoimmunotherapy.Firstly,a NIR-Ⅱ fluorophore MRP bearing donor-acceptor-donor(D-A-D) backbone was synthesized.Then,the prodrug nanotheranostics were prepared by self-assembling MRP with a prodrug of JQ1(JPC) and T7 ligand-modified PEG5k-DSPE.T7 can cross the BBB for tumor-targeted delivery of JPC and MRP.JQ1 could be restored from JPC at the tumor site for suppressing interferon gamma-inducible programmed death ligand 1 expression in the tumor cells.MRP could generate NIR-Ⅱ fluorescence to navigate 808 nm laser,induce a photothermal effect to trigger in-situ antigen release at the tumor site,and ultimately elicit antitumor immunogenicity.Photo-immunotherapy with JPC and MRP dual-loaded nanoparticles remarkably inhibited GBM tumor growth in vivo.The dual-targeting nanotheranostic might represent a novel nanoplatform for precise photo-immunotherapy of GBM.