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1.
Small ; 18(8): e2104142, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34881499

RESUMEN

Metal single atom catalysts (SAC) have been successfully used in heterogeneous catalysis but developing a scalable and economic support for SAC is still a great challenge. Here, cyclized polyacrylonitrile (CPAN) is proposed as a promising support for single atom metal catalysts. CPAN can be easily prepared from cheap industrial product polyacrylonitrile (PAN), which has excellent processability. A series of SAC on CPAN (M/CPAN, M = Ag, Cu, Ru) are designed and the catalytic activities of the as synthesized M/CPAN are investigated by the model reduction reaction of p-nitrophenol (4-NP). M/CPAN presents excellent catalytic performance with high stability and theoretical calculations elucidate that Ag/CPAN synergistically catalyze 4-NP reduction following the Langmuir-Hinshelwood (L-H) mechanism with 4-NP preferentially adsorbing at the Ag sites and H adsorbing at the bridge C sites. These results, for the first time, reveal that the single atom on CPAN can catalyze 4-NP reduction efficiently. This methodology provides a convenient route for the preparation of a variety of SAC, and this strategy is readily scalable and holds great potential in catalytic applications.


Asunto(s)
Resinas Acrílicas , Metales , Catálisis , Dominio Catalítico , Metales/química
2.
J Colloid Interface Sci ; 670: 297-310, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38763026

RESUMEN

Fenton/Fenton-like reaction induced chemical dynamic therapy (CDT) has been widely recognized in tumor therapy. Due to the low efficiency of conversion from high-valent metal ions (M(n+1)+) to low-valent ions (Mn+) in the Fenton/Fenton-like catalytic process, enhancing the conversion efficiency safely and effectively would create a great opportunity for the clinical application of CDT. In the study, a universal nanoreactor (NR) consisting of liposome (Lip), tumor cell membrane (CM), and bis(2,4,5-trichloro-6-carboxyphenyl) oxalate (CPPO) is developed to tackle this challenge. The CPPO was first discovered to decompose under weak acidity and H2O2 conditions to generate carboxylic acids (R'COOH) and alcohols (R'OH) with reducibility, which will reduce M(n+1)+ to Mn+ and magnify the effect of CDT. Furthermore, glucose oxidase (GOx) was introduced to decompose glucose in tumor and generate H2O2 and glucose acid, which promote the degradation of CPPO, further strengthening the efficiency of CDT, leading to a butterfly effect. This demonstrated that the butterfly effect triggered by NR and GOx encourages Fenton/Fenton-like reactions of Fe3O4 and MoS2, thereby enhancing the tumor inhibition effect. The strategy of combining GOx and CPPO to strengthen the Fenton/Fenton-like reaction is a universal strategy, which provides a new and interesting perspective for CPPO in the application of CDT, reflecting the exquisite integration of Fenton chemistry and catalytic medicine.


Asunto(s)
Peróxido de Hidrógeno , Peróxido de Hidrógeno/química , Humanos , Hierro/química , Liposomas/química , Glucosa Oxidasa/química , Glucosa Oxidasa/metabolismo , Animales , Propiedades de Superficie , Antineoplásicos/química , Antineoplásicos/farmacología , Oxalatos/química , Ratones , Tamaño de la Partícula , Supervivencia Celular/efectos de los fármacos
3.
J Mater Chem B ; 9(18): 3925-3934, 2021 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-33942817

RESUMEN

Nanozymes, as a kind of artificial mimic enzymes, have superior catalytic capacity and stability. As lack of O2 in tumor cells can cause resistance to drugs, we designed drug delivery liposomes (MnO2-PTX/Ce6@lips) loaded with catalase-like nanozymes of manganese dioxide nanoparticles (MnO2 NPs), paclitaxel (PTX) and chlorin e6 (Ce6) to consume tumor's native H2O2 and produce O2. Based on the catalysis of MnO2 NPs, a large amount of oxygen was produced by MnO2-PTX/Ce6@lips to burst the liposomes and achieve a responsive release of the loaded drug (paclitaxel), and the released O2 relieved the chemoresistance of tumor cells and provided raw materials for photodynamic therapy. Subsequently, MnO2 NPs were decomposed into Mn2+ in an acidic tumor environment to be used as contrast agents for magnetic resonance imaging. The MnO2-PTX/Ce6@lips enhanced the efficacy of chemotherapy and photodynamic therapy (PDT) in bearing-tumor mice, even achieving complete cure. These results indicated the great potential of MnO2-PTX/Ce6@lips for the modulation of the TME and the enhancement of chemotherapy and PDT along with MRI tracing in the treatment of tumors.


Asunto(s)
Nanoestructuras/uso terapéutico , Neoplasias/tratamiento farmacológico , Nanomedicina Teranóstica , Animales , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/metabolismo , Antineoplásicos Fitogénicos/farmacología , Antineoplásicos Fitogénicos/uso terapéutico , Supervivencia Celular/efectos de los fármacos , Clorofilidas , Medios de Contraste/química , Humanos , Peróxido de Hidrógeno/química , Peróxido de Hidrógeno/metabolismo , Luz , Liposomas/química , Imagen por Resonancia Magnética , Compuestos de Manganeso/química , Ratones , Nanopartículas/química , Nanoestructuras/química , Nanoestructuras/toxicidad , Neoplasias/diagnóstico por imagen , Óxidos/química , Oxígeno/química , Oxígeno/metabolismo , Paclitaxel/química , Paclitaxel/metabolismo , Paclitaxel/farmacología , Paclitaxel/uso terapéutico , Fotoquimioterapia , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/metabolismo , Fármacos Fotosensibilizantes/uso terapéutico , Porfirinas/química
4.
J Mater Chem B ; 9(9): 2323-2333, 2021 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-33621309

RESUMEN

Tumor-associated immunosuppression, as a key barrier, prevents immunotherapy-resistant tumors. In this study, an ingenious "nanoconverter" was designed to convert immunosuppression into immunoactivation, which was a C6-ceramide (C6)-modified tumor cytomembrane-coated polydopamine-paclitaxel system (PTX/PDA@M-C6). The co-administration of C6-ceramide and tumor cytomembrane changed an adaptive immune state to an activation state, which induced a robust antigen presentation ability of tumor-infiltrating dendritic cells to activate T1 helper cells and cytotoxic T lymphocytes. Meanwhile, C6-ceramide regulated the phenotype of macrophages via the reactive oxygen species pathway, which resulted in the conversion of M2-like macrophages by infiltration within tumors into M2-like macrophages, and therefore, M2-like macrophage-mediated immunosuppression was weakened distinctly. The "nanoconverter"-mediated conversion process upregulated the expression of related immune factors including interleukin-12, interleukin-6, tumor necrosis factor-α and interferon-γ and executed positive anti-tumor effects. In addition, under the protection of tumor-homologous cytomembrane, the "nanoconverter" exhibited excellent delivery efficiency (23.22%), and subsequently, accumulated special structural "nanoconverter" could break down into smaller nanoparticles for deep penetration into the tumor tissue under a NIR laser. Ultimately, chemo/thermal therapy-assisted immunotherapy completely eliminated the tumors of tumor-bearing mice, and a potent memory response relying on effector memory T cells still persisted to protect against tumor relapse after the end of treatment. The "nanoconverter" serves as a promising nanodrug delivery system for the conversion of immunosuppression and enhanced chemo/thermal therapy. Therefore, the highly cumulative "nanoconverter" has great potential for promoting the effect and clinical application of immunotherapy.


Asunto(s)
Inmunoterapia/métodos , Nanoestructuras/química , Animales , Transformación Celular Neoplásica , Ceramidas/química , Humanos , Indoles/química , Interferón gamma/metabolismo , Interleucina-12/metabolismo , Interleucina-6/metabolismo , Macrófagos/citología , Macrófagos/metabolismo , Ratones , Paclitaxel/química , Paclitaxel/metabolismo , Paclitaxel/farmacología , Fenotipo , Polímeros/química , Especies Reactivas de Oxígeno/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
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