Nanomaterials with enzyme‐mimicking activity (nanozymes) show potential for therapeutic interventions. However, it remains a formidable challenge to selectively kill tumor cells through enzymatic reactions, while leaving normal cells unharmed. Herein, we present a new strategy based on a single‐site cascade enzymatic reaction for tumor‐specific therapy that avoids off‐target toxicity to normal tissues. A copper hexacyanoferrate (Cu‐HCF) nanozyme with active single‐site copper exhibited cascade enzymatic activity within the tumor microenvironment: Tumor‐specific glutathione oxidase activity by the Cu‐HCF single‐site nanozymes (SSNEs) led to the depletion of intracellular glutathione and the conversion of single‐site CuII species into CuI for subsequent amplified peroxidase activity through a Fenton‐type Harber–Weiss reaction. In this way, abundant highly toxic hydroxyl radicals were generated for tumor cell apoptosis. The results show that SSNEs could amplify the tumor‐killing efficacy of reactive oxygen species and suppress tumor growth in vivo.
Organic optoelectronic functional
materials featuring circularly
polarized emission and persistent luminescence represent a novel research
frontier and show promising applications in data encryption, displays,
biological imaging, and so on. Herein, we present a simple and universal
approach to achieve circularly polarized organic phosphorescence (CPP)
from amorphous copolymers by the incorporation of axial chiral chromophores
into polymer chains via radical cross-linked polymerization. Our experimental
data reveal that copolymers (R/S)-PBNA exhibit a maximum CPP efficiency of 30.6% and the largest
dissymmetric factor of 9.4 × 10–3 and copolymers
(R/S)-PNA show the longest lifetime
of 0.68 s under ambient conditions. Given the CPP property of these
copolymers, their potential applications in multiple information encryption
and displays are demonstrated, respectively. These findings not only
lay the foundation for the development of amorphous polymers with
superior CPP but also expand the outlook of room-temperature phosphorescent
materials.
The therapeutic effect of chemodynamic therapy (CDT) is significantly restricted by the stern reaction conditions and slow reaction rate of the Fenton reaction (pH 3−4). Herein, we report an ultrasmall trimetallic (Pd, Cu, and Fe) alloy nanozyme (PCF-a NEs) possessing dynamic active-site synergism, thus exhibiting a cascade glutathione peroxidase and peroxidase (POD) mimicking activities in circumneutral pH. PCF-a NEs exhibit photothermally augmented POD property and high photothermal conversion efficiency (62%) for synergistic tumor cell apoptosis. In addition, ultrasound can also enhance the mass transfer at active catalytic sites of PCF-a NEs, in turn accelerating Fenton-like reaction for tumor-specific CDT. This work provides a strategy for engineering alloy nanozymes in a bioinspired way for the amplification of intratumor reactive oxygen species in response to external stimuli, demonstrating enhanced efficiency for the inhibition of tumor growth in vitro and in vivo.
Photodynamic therapy suffers from poor tumor selectivity and poor therapeutical efficacy. In this paper, an amphiphilic chimeric peptide is fabricated to realize sequential acidity‐responsive tumor‐targeted transport of photosensitizer and in situ photodynamic therapy in nuclei. In vitro studies demonstrate that the acidic tumor microenvironment successfully sheds the mask of cationic nuclear localization sequence (NLS) of the negatively charged chimeric peptide. This charge reversal remarkably accelerates cellular uptake of chimeric peptide in tumor cells and maximizes the photodynamic therapeutical efficacy in nuclei. Most importantly, direct disguise of the biofunctional NLS sequence decreases the complexity and increases the performance of the chimeric peptide further by achieving long blood retention time, specific tumor accumulation, minimal side effects, and efficient antitumor therapy in vivo.
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