Nanozymes have attracted extensive interest owing to their high stability, low cost and easy preparation, especially in the field of cancer therapy. However, the relatively low catalytic activity of nanozymes in the tumor microenvironment (TME) has limited their applications. Herein, we report a novel nanozyme (PtFe@Fe3O4) with dual enzyme‐like activities for highly efficient tumor catalytic therapy. PtFe@Fe3O4 shows the intrinsic photothermal effect as well as photo‐enhanced peroxidase‐like and catalase‐like activities in the acidic TME, thereby effectively killing tumor cells and overcoming the tumor hypoxia. Importantly, a possible photo‐enhanced synergistic catalytic mechanism of PtFe@Fe3O4 was first disclosed. We believe that this work will advance the development of nanozymes in tumor catalytic therapy.
The high reactive oxygen species (ROS) generation ability and simple construction of sonosensitizer systems remain challenging in sonodynamic therapy against the hypoxic tumor. In this work, we rationally prepared MOF‐derived double‐layer hollow manganese silicate nanoparticle (DHMS) with highly effective ROS yield under ultrasound irradiation for multimodal imaging‐guided sonodynamic therapy (SDT). The presence of Mn in DHMS increased ROS generation efficiency because it could be oxidized by holes to improve the electron–hole separation. Moreover, DHMS could produce oxygen in the tumor microenvironment, which helps overcome the hypoxia of the solid tumor and thus enhance the treatment efficiency. In vivo experiments demonstrated efficient tumor inhibition in DHMS‐mediated SDT guided by ultrasound and magnetic resonance imaging. This work presents a MOF‐derived nanoparticle with sonosensitive and oxygen generating ability, which provides a promising strategy for tumor hypoxia in SDT.
Although near‐infrared (NIR)‐light‐mediated photothermal thrombolysis has been investigated to overcome the bleeding risk of clinical clot‐busting agents, the secondary embolism of post‐phototherapy fragments (>10 µm) for small vessels should not be ignored in this process. In this study, dual‐modality photothermal/photodynamic thrombolysis is explored using targeting nanoagents with an emphasis on improving biosafety as well as ameliorating the thrombolytic effect. The nanoagents can actively target glycoprotein IIb/IIIa receptors on thrombus to initiate site‐specific thrombolysis by hyperthermia and reactive oxygen species under NIR laser irradiation. In comparison to single photothermal thrombolysis, an 87.9% higher re‐establishment rate of dual‐modality photothermal/photodynamic thrombolysis by one‐time treatment is achieved in a lower limb thrombosis model. The dual‐modality thrombolysis can also avoid re‐embolization after breaking fibrin into tiny fragments. All the results show that this strategy is a safe and validated protocol for thrombolysis, which fits the clinical translational trend of nanomedicine.
Carbon
nanomaterials have flourished for cancer therapy for decades.
However, their practical applications on clinical bases still pose
a challenge to address the dilemma of metabolism in vivo. In this study, an attempt is made to design a degradable carbon–silica
nanocomposite (CSN) with immunoadjuvant property, which could undergo
an enzyme-free degradation process into small particles (∼5
nm) and facilitate its clinical application. CSN harbors photothermal
and photodynamic properties and as an immunoadjuvant would help to
generate tumor-associated antigens and mature dendritic cells (DCs).
Potent antitumor effects have been achieved in both 4T1 and patient-derived
xenograft tumor models with tumor inhibition efficiencies of 93.2%
and 92.5%, respectively. We believe that this strategy will benefit
the possible clinical translation and carbon–silica-nanomaterial-based
cancer therapy.
Magnetic composites consisting of magnetite (Fe3O4), graphene oxide (GO), and Mg3Al-OH layered double hydroxide (LDH), denoted as MGL composites, with varying GO contents (RGO) were synthesized by a mechano-hydrothermal (MHT) route using Fe3O4, Mg(OH)2, and Al(OH)3 as the inorganic starting materials. The application of the synthesized MGLs for removing the heavy-metal Pb(II) and the hydrophobic organic pesticide 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous solutions was investigated. Chemical bonding among the GO, Fe3O4, and LDH components was observed in the MGLs. The MGL composites showed good water-dispersity, strong magnetic response, and high sorption capacities and removal efficiencies for both Pb(II) and 2,4-D pollutants. The sorption capacities of the MGL for the pollutants significantly increased with an increase in RGO. Increasing pH could increase the removal efficiency for Pb(II) but decrease that for 2,4-D. The MGLs showed more affinity for Pb(II) than for 2,4-D in the competitive sorption. In addition, the MGLs could remain almost constant removal efficiency for the pollutants after reuse over six cycles, indicating their potential use as sorbents in wastewater treatment. Furthermore, a Cs effect was observed in the sorption equilibriums, which could be described using the Langmuir-SCA and Freundlich-SCA isotherms. The removal mechanisms of the MGL for Pb(II) and 2,4-D were discussed. The MHT method provided a simple and environmentally friendly route for synthesizing GO-LDH composite materials.
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