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Hypoxia-Irrelevant Photonic Thermodynamic Cancer Nanomedicine
摘要： The hypoxic tumor microenvironment severely lowers the therapeutic efficacy of oxygen-dependent anticancer modalities because tumor hypoxia hinders the generation of toxic reactive oxygen species. Here we report a thermodynamic cancer-therapeutic modality that employs oxygen-irrelevant free radicals generated from thermo-labile initiators for inducing cancer-cell death. Free radical nanogenerator was engineered via direct growth of mesoporous silica layer onto the surface of two-dimensional Nb2C MXene nanosheets towards multifunctionality, where the mesopore provided the reservoirs for initiators and MXene core acted as the photonic-thermal trigger at near infrared-II biowindow (NIR-II). Upon illumination by a 1064 nm NIR-II laser, the photothermal-conversion effect of Nb2C MXene induced the fast release and quick decomposition of the encapsulated initiators (AIPH) to produce free radicals, which promoted cancer-cell apoptosis in both normoxic and hypoxic microenvironment. Systematic in vitro and in vivo evaluations have demonstrated the synergistic-therapeutic outcome of this intriguing photonic nanoplatform-enabled thermodynamic cancer therapy for completely eradicating the tumors without recurrence by NIR-II laser irradiation. This work pioneers the thermodynamic therapy for oxygen-independent cancer treatment by photonic triggering at NIR-II biowindow.
关键词： nanomedicine,thermodynamic therapy,photothermal effect,tumor hypoxia,free radicals
更新于2025-09-23 15:23:52
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Blue light photoredox decarboxylation and tin-free Barton-McCombie reactions in the stereoselective synthesis of (+)-muscarine
摘要： Starting from a 1,2-O-isopropylidene-D-xylofuranose derivative, a non-toxic free-radical approach for the synthesis of (+)-muscarine is reported. To this end, a stereoselective allylation reaction at the anomeric position of a respective xylofuranose derivative was employed as a new synthetic strategy for the installation of the methyl group at the C-5 position of (+)-muscarine. Accordingly, the allyl group was transformed into the methyl group in three sequential steps highlighting a blue-light photoredox decarboxylation reaction. Additionally, a tin-free Barton-McCombie deoxygenation reaction of the respective C-methyl glycoside allowed the completion of this free-radical approach to (+)-muscarine.
关键词： C-glycosylation,chiron approach,free radicals,Photoredox reaction
更新于2025-09-23 15:23:52
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Self-assembled flower-like (BiO)2CO3a??CdSa??CuS stable heterojunction degrades toluene under visible light response
摘要： The toluene as a representative VOCs is not only difficult to degrade, but also very harmful. In this manuscript, we use photocatalytic materials to degrade toluene. At first, the sheet-like structure decorated (BiO)2CO3 flowers were fabricated. The tight decoration of sheet-like structure over (BiO)2CO3 flowers provided greater specific surface area to contact with the toluene. Finally, the (BiO)2CO3 and CdS–CuS were fabricated to form a ternary heterojunction by one-step hydrothermal method. The activity enhancement should be ascribed to that the ternary heterojunction could produce more active material ?OH for toluene degradation. The 3p-orbital in the sulfur atom in CuS can be used as an electron acceptor to effectively improve the stability of sulfur vacancies on the surface of CdS. In addition, the presence of CuS could solve the problem of deactivation caused by photo-etching of CdS under illumination conditions. The valence change of the S element in CuS-CdS-BOC is only 1.1%, but up to 7.5% in CdS-BOC before and after the reaction. The highest degradation effect was exhibited, the degradation of toluene at 3000 ppm could reach 67%. In addition, The band gap of the composite material was reduced from 3.2eV to 2.25eV. A new alternative catalytic material was provided for the degradation of toluene. A reliable strategy was provide for enhancing the stability of S in CdS by this work.
关键词： Toluene,Stability,Photocatalysis,Free radicals
更新于2025-09-23 15:21:01
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Role of intermediate species in the formation of an energetic ion latent track in PADC: A review
摘要： This review paper intends at identifying the early processes arising during the formation of a latent ion track in Poly Allyl Diglycol Carbonate (PADC). We briefly summarize the physical and chemical processes specific to the description of the interaction of ionizing radiation with matter. Then we gather published information in relation to PADC response regarding energy absorption and further transient species formation. Emphasis is given to the chemistry of radicals. Due to a lack of available data in relation with clearly identified unpaired electron carriers in PADC, we use data stemming from surrogate molecules. Based on such data we suggest mechanisms for the decomposition of PADC during the early times of ion track formation. The a-sites of ether functional groups in PADC appear undoubtedly as critical targets which during further decomposition behave as the most probable origin of Carbon dioxide release. All suggested mechanisms are multi-step processes. Combining different concepts and data in relation with the dynamics of transient species formed in the ion track of a polymer material, we propose that the effective track radius may be described as the radial extension of reactive species formed rather than the maximum distance at which d-rays escape out of ion’s trajectory. Lastly, generalization of the different processes collected allows two major pathways to be proposed for describing the fate of damaged ether moieties in PADC. This way, evidence is given for a higher sensitivity of ether functional groups compared to ester carbonate ones. The latter generally being destroyed as a consequence of prior damaging of the ether group.
关键词： Latent track,latent track dynamics,Track core & penumbra,Free radicals,PADC
更新于2025-09-19 17:15:36
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Hyperthermia and Controllable Free Radicals Co-Enhanced Synergistic Therapy in Hypoxia Enabled by Near-Infrared-II Light Irradiation
摘要： Tumor cells metabolism and tumor blood vessels proliferation represent in a distinctive way compared to normal cells. The resulting tumor microenvironment will presents a characteristic of hypoxia, which greatly limits the generation of oxygen free radicals and affects the therapeutic effect of photodynamic therapy. Here, we developed an oxygen-independent free radicals generated nanosystem (CuFeSe2-AIPH@BSA) with dual-peak absorption in both near-infrared (NIR) regions and utilized it for imaging-guided synergistic treatment. The special absorption endows the nanosystem with high photothermal conversion efficiency and favorably matched photoactivity in both (I and II) NIR biological windows. Upon NIR light irradiation, the generated heat could prompt AIPH release and decompose, and then to produce oxygen-independent free radicals for killing cancer cells effectively. The contrastive research results show the enhanced therapeutic efficacy of NIR-II over NIR-I principally due to its deeper tissue penetration and higher maximum permission exposure benefited from longer wavelength. Hyperthermia effect and the production of toxic free radicals upon NIR-II laser illumination are extremely effective in triggering apoptosis and death of cancer cells in tumor hypoxia microenvironment. The high biocompatibility and excellent anti-cancer efficiency of CuFeSe2-AIPH@BSA allow it to be an ideal oxygen-independent nanosystem for imaging-guided and NIR-II-mediated synergistic therapy via systemic administration.
关键词： second near-infrared window,free radicals,photothermal,hypoxia,oxygen-independent,CuFeSe2
更新于2025-09-19 17:13:59
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The Ability of Functionalized Fullerenes and Surface Modified TiO <sub/>2</sub> Nanoparticles to Photosensitize Peroxidation of Lipids in Selected Model Systems
摘要： Photochemical properties of a new class of inorganic nanoparticles, namely a cationic C60 fullerene substituted with three quaternary pyrrolidinium groups (BB6) and a surface modified nanocrystalline TiO2 with bromopyrogallol red (Brp@TiO2) were examined for their effectiveness in photogenerating singlet oxygen and free radicals. In particular, their ability to photosensitize peroxidation of unsaturated lipids was analyzed in POPC:cholesterol liposomes and B16 mouse melanoma cells employing a range of spectroscopic and analytical methods. Because melanoma cells typically are pigmented, we examined the effect of melanin on the photosensitized peroxidation of lipids in liposomes and B16 melanoma cells, mediated by BB6 and Brp@TiO2 nanoparticles. The obtained results suggest that peroxidation of unsaturated lipids, photosensitized by BB6 occurs mainly, although not exclusively, via Type II mechanism involving singlet oxygen. On the other hand, if surface modified TiO2 is used as a photosensitizer, Type I mechanism of lipid peroxidation dominates, as indicated by the predominant formation of the free-radical dependent cholesterol oxidation products. The protective effect of melanin was particularly evident when BB6 was used as a photosensitizer, suggesting that melanin could efficiently interfere with Type II processes.
关键词： Lipid peroxidation,Melanin,Fullerenes,Singlet oxygen,TiO2 nanoparticles,Free radicals,Photodynamic therapy
更新于2025-09-10 09:29:36