Bioresponsive Polyoxometalate Cluster for Redox-Activated Photoacoustic Imaging-Guided Photothermal Cancer Therapy

Abstract

Although various types of imaging agents have been developed for photoacoustic (PA) imaging, relatively few imaging agents exhibit high selectivity/sensitivity to the tumor microenvironment for on-demand PA imaging and therapy. Herein, molybdenum-based polyoxometalate (POM) clusters with the highest oxidation state of Mo(VI) (denoted as Ox-POM) were designed as novel agents for redox-activated PA imaging-guided photothermal therapy (PTT). Capable of escaping from recognition and capture by the liver and spleen, these renal clearable clusters with ultra-small size (hydrodynamic size: 1.9 nm) can accumulate in the tumor, self-assemble into larger nanoclusters at low pH, and are reduced to NIR absorptive agents in the tumor microenvironment. Studies in 4T1 tumor-bearing mice indicated that these clusters could be employed for bio-responsive PA imaging-guided tumor ablation in vivo. Our finding is expected to establish a new physicochemical paradigm for the design of PA imaging agents based on clusters, bridging the conventional concepts of “molecule” and “nano” in the bio-imaging field.

Two‐Dimensional Antimonene‐Based Photonic Nanomedicine for Cancer Theranostics

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Tumor Microenvironment‐Responsive Mesoporous MnO2‐Coated Upconversion Nanoplatform for Self‐Enhanced Tumor Theranostics

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Phase‐Change Materials Based Nanoparticles for Controlled Hypoxia Modulation and Enhanced Phototherapy

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