7 research outputs found

    Bottom-Up Synthesis of Metal-Ion-Doped WS<sub>2</sub> Nanoflakes for Cancer Theranostics

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    Recently, two-dimensional transition metal dichalcogenides (TMDCs) have received tremendous attention in many fields including biomedicine. Herein, we develop a general method to dope different types of metal ions into WS<sub>2</sub> nanoflakes, a typical class of TMDCs, and choose Gd<sup>3+</sup>-doped WS<sub>2</sub> (WS<sub>2</sub>:Gd<sup>3+</sup>) with polyethylene glycol (PEG) modification as a multifunctional agent for imaging-guided combination cancer treatment. While WS<sub>2</sub> with strong near-infrared (NIR) absorbance and X-ray attenuation ability enables contrasts in photoacoustic (PA) imaging and computed tomography (CT), Gd<sup>3+</sup> doping offers the nanostructure a paramagnetic property for magnetic resonance (MR) imaging. As revealed by trimodal PA/CT/MR imaging, WS<sub>2</sub>:Gd<sup>3+</sup>-PEG nanoflakes showed efficient tumor homing after intravenous injection. <i>In vivo</i> cancer treatment study further uncovered that WS<sub>2</sub>:Gd<sup>3+</sup>-PEG could not only convert NIR light into heat for photothermal therapy (PTT) but also enhance the ionizing irradiation-induced tumor damage to boost radiation therapy (RT). Owing to the improved tumor oxygenation after the mild PTT, the combination of PTT and RT induced by WS<sub>2</sub>:Gd<sup>3+</sup>-PEG resulted in a remarkable synergistic effect to destroy cancer. Our work highlights the promise of utilizing inherent physical properties of TMDC-based nanostructures, whose functions could be further enriched by elementary doping, for applications in multimodal bioimaging and synergistic cancer therapy

    Antigen-Loaded Upconversion Nanoparticles for Dendritic Cell Stimulation, Tracking, and Vaccination in Dendritic Cell-Based Immunotherapy

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    A dendritic cell (DC) vaccine, which is based on efficient antigen delivery into DCs and migration of antigen-pulsed DCs to draining lymph nodes after vaccination, is an effective strategy in initiating CD8<sup>+</sup> T cell immunity for immunotherapy. Herein, antigen-loaded upconversion nanoparticles (UCNPs) are used to label and stimulate DCs, which could be precisely tracked after being injected into animals and induce an antigen-specific immune response. It is discovered that a model antigen, ovalbumin (OVA), could be adsorbed on the surface of dual-polymer-coated UCNPs <i>via</i> electrostatic interaction, forming nanoparticleā€“antigen complexes, which are efficiently engulfed by DCs and induce DC maturation and cytokine release. Highly sensitive <i>in vivo</i> upconversion luminescence (UCL) imaging of nanoparticle-labeled DCs is successfully carried out, observing the homing of DCs to draining lymph nodes after injection. In addition, strong antigen-specific immune responses including enhanced T cell proliferation, interferon gamma (IFN-Ī³) production, and cytotoxic T lymphocyte (CTL)-mediated responses are induced by a nanoparticle-pulsed DC vaccine, which is promising for DC-based immunotherapy potentially against cancer

    Graphene-Based Nanocomposite As an Effective, Multifunctional, and Recyclable Antibacterial Agent

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    The development of new antibacterial agents that are highly effective are of great interest. Herein, we present a recyclable and synergistic nanocomposite by growing both iron oxide nanoparticles (IONPs) and silver nanoparticles (AgNPs) on the surface of graphene oxide (GO), obtaining GO-IONP-Ag nanocomposite as a novel multifunctional antibacterial material. Compared with AgNPs, which have been widely used as antibacterial agents, our GO-IONP-Ag shows much higher antibacterial efficiency toward both Gram-negative bacteria <i>Escherichia coli</i> (<i>E. coli</i>) and Gram-positive bacteria <i>Staphylococcus aureus</i> (<i>S. aureus</i>). Taking the advantage of its strong near-infrared (NIR) absorbance, photothermal treatment is also conducted with GO-IONP-Ag, achieving a remarkable synergistic antibacterial effect to inhibit <i>S. aureus</i> at a rather low concentration of this agent. Moreover, with magnetic IONPs existing in the composite, we can easily recycle GO-IONP-Ag by magnetic separation, allowing its repeated use. Given the above advantages as well as its easy preparation and cheap cost, GO-IONP-Ag developed in this work may find potential applications as a useful antibacterial agent in the areas of healthcare and environmental engineering

    Hyaluronidase To Enhance Nanoparticle-Based Photodynamic Tumor Therapy

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    Photodynamic therapy (PDT) is considered as a safe and selective way to treat a wide range of cancers as well as nononcological disorders. However, as oxygen is required in the process of PDT, the hypoxic tumor microenvironment has largely limited the efficacy of PDT to treat tumors especially those with relatively large sizes. To this end, we uncover that hyaluronidase (HAase), which breaks down hyaluronan, a major component of extracellular matrix (ECM) in tumors, would be able to enhance the efficacy of nanoparticle-based PDT for in vivo cancer treatment. It is found that the administration of HAase would lead to the increase of tumor vessel densities and effective vascular areas, resulting in increased perfusion inside the tumor. As a result, the tumor uptake of nanomicelles covalently linked with chlorine e6 (NM-Ce6) would be increased by āˆ¼2 folds due to the improved ā€œenhanced permeability and retentionā€ (EPR) effect, while the tumor oxygenation level also shows a remarkable increase, effectively relieving the hypoxia state inside the tumor. Those effects taken together offer significant benefits in greatly improving the efficacy of PDT delivered by nanoparticles. Taking advantage of the effective migration of HAase from the primary tumor to its drainage sentinel lymph nodes (SLNs), we further demonstrate that this strategy would be helpful to the treatment of metastatic lymph nodes by nanoparticle-based PDT. Lastly, both enhanced EPR effect of NM-Ce6 and relieved hypoxia state of tumor are also observed after systemic injection of modified HAase, proving its potential for clinical translation. Therefore, our work presents a new concept to improve the efficacy of nanomedicine by modulating the tumor microenvironment

    Dual-Modality Positron Emission Tomography/Optical Image-Guided Photodynamic Cancer Therapy with Chlorin e6-Containing Nanomicelles

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    Multifunctional nanoparticles with combined diagnostic and therapeutic functions show great promise in nanomedicine. Herein, we develop an organic photodynamic therapy (PDT) system based on polyethylene glycol (PEG)-coated nanomicelles conjugated with āˆ¼20% chlorin e6 (PEG-Ce 6 nanomicelles), which functions as an optical imaging agent, as well as a PDT agent. The formed PEG-Ce 6 nanomicelles with the size of āˆ¼20 nm were highly stable in various physiological solutions for a long time. Moreover, Ce 6 can also be a <sup>64</sup>Cu chelating agent for <i>in vivo</i> positron emission tomography (PET). By simply mixing, more than 90% of <sup>64</sup>Cu was chelator-free labeled on PEG-Ce 6 nanomicelles, and they also showed high stability in serum conditions. Both fluorescence imaging and PET imaging revealed that PEG-Ce 6 nanomicelles displayed high tumor uptake (13.7 Ā± 2.2%ID/g) after intravenous injection into tumor-bearing mice at the 48 h time point. In addition, PEG-Ce 6 nanomicelles exhibited excellent PDT properties upon laser irradiation, confirming the theranostic properties of PEG-Ce 6 nanomicelles for imaging and treatment of cancer. In addition, PDT was not shown to render any appreciable toxicity. This work presents a theranostic platform based on polymer nanomicelles with great potential in multimodality imaging-guided photodynamic cancer therapy

    Discovery of 6ā€‘Fluoro-5ā€‘(<i>R</i>)ā€‘(3ā€‘(<i>S</i>)ā€‘(8-fluoro-1-methyl-2,4-dioxo-1,2-dihydroquinazolin-3(4<i>H</i>)ā€‘yl)-2-methylphenyl)-2ā€‘(<i>S</i>)ā€‘(2-hydroxypropan-2-yl)-2,3,4,9-tetrahydroā€‘1<i>H</i>ā€‘carbazole-8-carboxamide (BMS-986142): A Reversible Inhibitor of Brutonā€™s Tyrosine Kinase (BTK) Conformationally Constrained by Two Locked Atropisomers

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    Bruton's tyrosine kinase (BTK), a nonreceptor tyrosine kinase, is a member of the Tec family of kinases. BTK plays an essential role in B cell receptor (BCR)-mediated signaling as well as FcĪ³ receptor signaling in monocytes and FcĪµ receptor signaling in mast cells and basophils, all of which have been implicated in the pathophysiology of autoimmune disease. As a result, inhibition of BTK is anticipated to provide an effective strategy for the clinical treatment of autoimmune diseases such as lupus and rheumatoid arthritis. This article details the structureā€“activity relationships (SAR) leading to a novel series of highly potent and selective carbazole and tetrahydrocarbazole based, reversible inhibitors of BTK. Of particular interest is that two atropisomeric centers were rotationally locked to provide a single, stable atropisomer, resulting in enhanced potency and selectivity as well as a reduction in safety liabilities. With significantly enhanced potency and selectivity, excellent in vivo properties and efficacy, and a very desirable tolerability and safety profile, <b>14f</b> (BMS-986142) was advanced into clinical studies

    Identification of a Potent, Selective, and Efficacious Phosphatidylinositol 3ā€‘Kinase Ī“ (PI3KĪ“) Inhibitor for the Treatment of Immunological Disorders

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    PI3KĪ“ plays an important role controlling immune cell function and has therefore been identified as a potential target for the treatment of immunological disorders. This article highlights our work toward the identification of a potent, selective, and efficacious PI3KĪ“ inhibitor. Through careful SAR, the successful replacement of a polar pyrazole group by a simple chloro or trifluoromethyl group led to improved Caco-2 permeability, reduced Caco-2 efflux, reduced hERG PC activity, and increased selectivity profile while maintaining potency in the CD69 hWB assay. The optimization of the aryl substitution then identified a 4ā€²-CN group that improved the human/rodent correlation in microsomal metabolic stability. Our lead molecule is very potent in PK/PD assays and highly efficacious in a mouse collagen-induced arthritis model
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