RESUMEN

Copper-catalyzed click chemistry offers creative strategies for activation of therapeutics without disrupting biological processes. Despite tremendous efforts, current copper catalysts face fundamental challenges in achieving high efficiency, atom economy, and tissue-specific selectivity. Herein, we develop a facile "mix-and-match synthetic strategy" to fabricate a biomimetic single-site copper-bipyridine-based cerium metal-organic framework (Cu/Ce-MOF@M) for efficient and tumor cell-specific bioorthogonal catalysis. This elegant methodology achieves isolated single-Cu-site within the MOF architecture, resulting in exceptionally high catalytic performance. Cu/Ce-MOF@M favors a 32.1-fold higher catalytic activity than the widely used MOF-supported copper nanoparticles at single-particle level, as first evidenced by single-molecule fluorescence microscopy. Furthermore, with cancer cell-membrane camouflage, Cu/Ce-MOF@M demonstrates preferential tropism for its parent cells. Simultaneously, the single-site CuII species within Cu/Ce-MOF@M are reduced by upregulated glutathione in cancerous cells to CuI for catalyzing the click reaction, enabling homotypic cancer cell-activated in situ drug synthesis. Additionally, Cu/Ce-MOF@M exhibits oxidase and peroxidase mimicking activities, further enhancing catalytic cancer therapy. This study guides the reasonable design of highly active heterogeneous transition-metal catalysts for targeted bioorthogonal reactions.

Asunto(s)

Materiales Biomiméticos , Cobre , Humanos , Cobre/química , Materiales Biomiméticos/química , Catálisis , Estructuras Metalorgánicas/química , Neoplasias/tratamiento farmacológico , Neoplasias/terapia , Cerio/química , Línea Celular Tumoral , Animales , Química Clic/métodos , Biomimética/métodos , Ratones

RESUMEN

Herein, a nanocomposite of Cu,Ce-containing phosphotungstates (Cu,Ce-PTs) with outstanding laccase-like activity was fabricated via a one-pot microwave-assisted hydrothermal method. Notably, it was discovered that both Fe3+ and Cr6+ could significantly enhance the electron transfer rates of Ce3+ and Ce4+, along with generous Cu2+ with high catalytic activity, thereby promoting the laccase-like activity of Cu,Ce-PTs. The proposed system can be used for the detection of Fe3+ and Cr6+ in a range of 0.667-333.33 µg/mL and 0.033-33.33 µg/mL with a low detection limit of 0.135 µg/mL and 0.0288 µg/mL, respectively. The proposed assay exhibits excellent reusability and selectivity and can be used in traditional Chinese medicine samples analysis.

Asunto(s)

Cerio , Cromo , Colorimetría , Cobre , Hierro , Lacasa , Cobre/análisis , Cobre/química , Cromo/análisis , Colorimetría/métodos , Lacasa/metabolismo , Lacasa/química , Hierro/análisis , Hierro/química , Cerio/química , Límite de Detección , Ácido Fosfotúngstico/química , Nanocompuestos/química , Catálisis

RESUMEN

Cerium and cobalt loaded Co-Ce/TiO2 catalyst prepared by impregnation method was investigated for photothermal catalytic toluene oxidation. Based on catalyst characterizations (XPS, EPR and H2-TPR), redox cycle between Co and TiO2 (Co2+ + Ti4+ ↔ Co3+ + Ti3+) results in the formation of Co3+, Ti3+ and oxygen vacancies, which play important roles in toluene catalytic oxidation reaction. The introduction of Ce brings in the dual redox cycles (Co2+ + Ti4+ ↔ Co3+ + Ti3+, Co2+ + Ce4+ ↔ Co3+ + Ce3+), further promoting the elevation of reaction sites amount. Under full spectrum irradiation with light intensity of 580 mW/cm2, Co-Ce/TiO2 catalyst achieved 96% of toluene conversion and 73% of CO2 yield, obviously higher than Co/P25 and Co/TiO2. Co-Ce/TiO2 efficiently maintains 10-hour stability test under water vapor conditions and exhibits better photothermal catalytic performance than counterparts under different wavelengths illumination. Photothermal catalytic reaction displays improved activities compared with thermal catalysis, which is attributed to the promotional effect of light including photocatalysis and light activation of reactive oxygen species.

Asunto(s)

Cerio , Cobalto , Oxidación-Reducción , Titanio , Tolueno , Titanio/química , Cobalto/química , Catálisis , Tolueno/química , Cerio/química , Modelos Químicos , Procesos Fotoquímicos

RESUMEN

Reducing the cost of RuO2/TiO2 catalysts is still one of the urgent challenges in catalytic HCl oxidation. In the present work, a Ce-doped TiO2 supported RuO2 catalyst with a low Ru loading was developed, showing a high activity in the catalytic oxidation of HCl to Cl2. The results on some extensive characterizations of both Ce-doped TiO2 carriers and their supported RuO2 catalysts show that the doping of Ce into TiO2 can effectively change the lattice parameters of TiO2 to improve the dispersion of the active RuO2 species on the carrier, which facilitates the production of surface Ru species to expose more active sites for boosting the catalytic performance even under some harsh reaction conditions. This work provides some scientific basis and technical support for chlorine recycling.

Asunto(s)

Cerio , Ácido Clorhídrico , Oxidación-Reducción , Titanio , Titanio/química , Catálisis , Cerio/química , Ácido Clorhídrico/química , Compuestos de Rutenio/química , Cloruros/química , Modelos Químicos , Cloro/química

RESUMEN

Herein, three supported catalysts, CuO/Al2O3, CeO2/Al2O3, and CuO-CeO2/Al2O3, were synthesized by the convenient impregnation method to reveal the effect of CeO2 addition on catalytic performance and reaction mechanism for toluene oxidation. Compared with CuO/Al2O3, the T50 and T90 (the temperatures at 50% and 90% toluene conversion, respectively) of CuO-CeO2/Al2O3 were reduced by 33 and 39 °C, respectively. N2 adsorption-desorption experiment, XRD, SEM, EDS mapping, Raman, EPR, H2-TPR, O2-TPD, XPS, NH3-TPD, Toluene-TPD, and in-situ DRIFTS were conducted to characterize these catalysts. The excellent catalytic performance of CuO-CeO2/Al2O3 could be attributed to its strong copper-cerium interaction and high oxygen vacancies concentration. Moreover, in-situ DRIFTS proved that CuO-CeO2/Al2O3 promoted the conversion of toluene to benzoate and accelerated the deep degradation path of toluene. This work provided valuable insights into the development of efficient and economical catalysts for volatile organic compounds.

Asunto(s)

Cerio , Cobre , Oxidación-Reducción , Tolueno , Tolueno/química , Catálisis , Cobre/química , Cerio/química , Modelos Químicos , Contaminantes Atmosféricos/química

RESUMEN

Catalytic destruction is an ascendant technology for the abatement of volatile organic compounds (VOCs) originating from solvent-based industrial processes. The varied composition tends to influence each VOC's catalytic behavior in the reaction mixture. We investigated the catalytic destruction of multi-component VOCs including dichloromethane (DCM) and ethyl acetate (EA), as representatives from pharmaceutical waste gases, over co-supported HxPO4-RuOx/CeO2 catalyst. A mutual inhibitory effect relating to concentrations because of competitive adsorption was verified in the binary VOCs oxidation and EA posed a more negative effect on DCM oxidation owing to EA's superior adsorption capacity. Preferential adsorption of EA on acidic sites (HxPO4/CeO2) promoted DCM activation on basic sites (O2-) and the dominating EA oxidation blocked DCM's access to oxidation centers (RuOx/CeO2), resulting in boosted monochloromethane yield and increased chlorine deposition for DCM oxidation. The impaired redox ability of Ru species owing to chlorine deposition in turn jeopardized deep oxidation of EA and its by-products, leading to increased gaseous by-products such as acetic acid originating from EA pyrolysis. Notably, DCM at low concentration slightly promoted EA conversion at low temperatures with or without water, consistent with the enhanced EA adsorption in co-adsorption analyses. This was mainly due to that DCM impeded the shielding effect of hydrolysate deposition from rapid EA hydrolysis depending on the decreased acidity. Moreover, water benefited EA hydrolysis but decreased CO2 selectivity while the generated water derived from EA was likely to affect DCM transformation. This work may provide theoretical guidance for the promotion of applied catalysts toward industrial applications.

Asunto(s)

Acetatos , Cerio , Cloruro de Metileno , Acetatos/química , Catálisis , Cloruro de Metileno/química , Cerio/química , Compuestos Orgánicos Volátiles/química , Adsorción , Oxidación-Reducción , Rutenio/química

RESUMEN

Phosphates within tumors function as key biomolecules, playing a significant role in sustaining the viability of tumors. To disturb the homeostasis of cancer cells, regulating phosphate within the organism proves to be an effective strategy. Herein, we report single-atom Ce-doped Pt hydrides (Ce/Pt-H) with high phosphatase-like activity for phosphate hydrolysis. The resultant Ce/Pt-H exhibits a 26.90- and 6.25-fold increase in phosphatase-like activity in comparison to Ce/Pt and Pt-H, respectively. Mechanism investigations elucidate that the Ce Lewis acid site facilitates the coordination with phosphate groups, while the surface hydrides enhance the electron density of Pt for promoting catalytic ability in H2O cleavage and subsequent nucleophilic attack of hydroxyl groups. Finally, by leveraging its phosphatase-like activity, Ce/Pt-H can effectively regulate intracellular phosphates to disrupt redox homeostasis and amplify oxidative stress within cancer cells, ultimately leading to tumor apoptosis. This work provides fresh insights into noble-metal-based phosphatase mimics for inducing tumor apoptosis.

Asunto(s)

Apoptosis , Cerio , Estrés Oxidativo , Estrés Oxidativo/efectos de los fármacos , Cerio/química , Cerio/farmacología , Apoptosis/efectos de los fármacos , Humanos , Monoéster Fosfórico Hidrolasas/metabolismo , Monoéster Fosfórico Hidrolasas/química , Antineoplásicos/farmacología , Antineoplásicos/química , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ratones

RESUMEN

We design a multi-effective nanoplatform (CeO2:Nd@SiO2@CeO2:Yb,Er@SiO2-RB/MB/CD36) with down/upconversion dual-mode emissions and targeting ability in foam macrophages. Under NIR excitation, this nanoplatform can realize in vivo NIR-II imaging and PDT/PTT coordinated therapy for early AS simultaneously.

Asunto(s)

Aterosclerosis , Rayos Infrarrojos , Fotoquimioterapia , Animales , Aterosclerosis/tratamiento farmacológico , Aterosclerosis/diagnóstico por imagen , Ratones , Dióxido de Silicio/química , Nanopartículas/química , Imagen Óptica , Humanos , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/síntesis química , Células RAW 264.7 , Cerio/química , Cerio/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo

RESUMEN

The design of a catalyst with multifunctional sites is one of the effective methods for low-temperature catalytic oxidation of chlorinated volatile organic compounds (CVOCs). The loss of redox sites and competitive adsorption of H2O prevalent in the treatment of industrial exhaust gases are the main reasons for the weak mineralization ability and poor water vapor resistance of V-based catalysts. In this work, platinum (Pt) is selected to combine with the V/CeO2 catalyst, which provides more redox sites and H2O dissociative activation sites and further enhances its catalytic performance. The results show that PtV/CeO2 achieves 90% of the CO2 yield at 318 °C and maintains excellent catalytic activity rather than continuous deactivation within 15 h after water vapor injection. The formation of Pt-O-V bonds enhances the redox ability and promotes deep oxidation of polychlorinated intermediates, accounting for the significantly improved mineralization ability of PtV/CeO2. The dissociative activation effect of Pt on H2O molecules strengthens the migration and activation of V-adsorbed H2O, precluding V-poisoning and notably improving water resistance. This study lays a solid foundation for the efficient degradation of chlorobenzene under humid conditions.

Asunto(s)

Clorobencenos , Oxidación-Reducción , Platino (Metal) , Agua , Catálisis , Platino (Metal)/química , Clorobencenos/química , Agua/química , Vanadio/química , Cerio/química

RESUMEN

Caffeic acid (CA) is a natural polyphenol that can have various positive effects on human health. However, its extraction and processing can cause significant ecological issues. Therefore, it is crucial to detect and degrade CA effectively in the environment. In this study, we have developed a multifunctional magnetic luminescent nanozyme, Fe3O4@CeO2/Tb-MOF, which combines peroxidase activity to detect and degrade CA. The fluorescence of the nanozyme was significantly attenuated due to the specific nucleophilic reaction between its boronic acid moiety and the o-diphenol hydroxyl group of CA, energy competition absorption and photo-induced electron transfer (PET) effect. This nanozyme demonstrates a linear detection range from 50 nM to 500 µM and an exceptionally low detection limit of 18.9 nM, along with remarkable selectivity and stability. Moreover, the synergistic catalysis of Fe3O4 and CeO2 within Fe3O4@CeO2/Tb-MOF fosters peroxidase activity, leading to the generation of substantial free radicals catalyzed by H2O2, which ensures the efficient degradation of CA (∼95%). The superparamagnetic property of Fe3O4 further enables the efficient reuse and recycling of the nanozyme. This research provides a novel approach for the concurrent detection and remediation of environmental contaminants.

Asunto(s)

Técnicas Biosensibles , Ácidos Cafeicos , Cerio , Límite de Detección , Ácidos Cafeicos/química , Ácidos Cafeicos/análisis , Técnicas Biosensibles/métodos , Cerio/química , Estructuras Metalorgánicas/química , Terbio/química , Ácidos Borónicos/química , Espectrometría de Fluorescencia/métodos , Peróxido de Hidrógeno/química , Fluorescencia , Ácidos Bóricos

RESUMEN

Cerium oxide nanoparticles are known for their antibacterial effects resulting from Ce3+ to Ce4+ conversion. Application of such cerium oxide nanoparticles in dentistry has been previously considered but limited due to deterioration of mechanical properties. Hence, this study aimed to examine mesoporous silica (MCM-41) coated with cerium oxide nanoparticles and evaluate the antibacterial effects and mechanical properties when applied to dental composite resin. Cerium oxide nanoparticles were coated on the MCM-41 surface using the sol-gel method by adding cerium oxide nanoparticle precursor to the MCM-41 dispersion. The samples were tested for antibacterial activity against Streptococcus mutans via CFU and MTT assays. The mechanical properties were assessed by flexural strength and depth of cure according to ISO 4049. Data were analyzed using a t-test, one-way ANOVA, and Tukey's post-hoc test (p = 0.05). The experimental group showed significantly increased antibacterial properties compared to the control groups (p < 0.005). The flexural strength exhibited a decreasing trend as the amount of cerium oxide nanoparticle-coated MCM-41 increased. However, the flexural strength and depth of cure values of the silane group met the ISO 4049 standard. Antibacterial properties increased with increasing amounts of cerium oxide nanoparticles. Although the mechanical properties decreased, silane treatment overcame this drawback. Hence, the cerium oxide nanoparticles coated on MCM-41 may be used for dental resin composite.

Asunto(s)

Antibacterianos , Cerio , Resinas Compuestas , Nanopartículas , Dióxido de Silicio , Streptococcus mutans , Cerio/química , Cerio/farmacología , Dióxido de Silicio/química , Antibacterianos/farmacología , Antibacterianos/química , Resinas Compuestas/química , Resinas Compuestas/farmacología , Streptococcus mutans/efectos de los fármacos , Nanopartículas/química , Resinas Acrílicas/química , Ensayo de Materiales , Poliuretanos/química , Poliuretanos/farmacología , Resistencia Flexional , Porosidad

RESUMEN

Myocardial infarction (MI) has a 5-year mortality rate of more than 50% due to the lack of effective treatments. Interactions between cardiomyocytes and the MI microenvironment (MIM) can determine the progression and fate of infarcted myocardial tissue. Here, a specially designed Melanin-based composite nanomedicines (MCN) is developed to effectively treat MI by reprogramming the MIM. MCN is a nanocomposite composed of polydopamine (P), Prussian blue (PB) and cerium oxide (CexOy) with a Mayuan-like structure, which reprogramming the MIM by the efficient conversion of detrimental substances (H+, reactive oxygen species, and hypoxia) into beneficial status (O2 and H2O). In coronary artery ligation and ischemia reperfusion models of male mice, intravenously injecting MCN specifically targets the damaged area, resulting in restoration of cardiac function. With its promising therapeutic effects, MCN constitutes a new agent for MI treatment and demonstrates potential for clinical application.

Asunto(s)

Cerio , Indoles , Melaninas , Infarto del Miocardio , Nanomedicina , Polímeros , Animales , Melaninas/metabolismo , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/patología , Masculino , Ratones , Nanomedicina/métodos , Indoles/química , Polímeros/química , Cerio/química , Cerio/farmacología , Cerio/administración & dosificación , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Nanocompuestos/química , Modelos Animales de Enfermedad , Especies Reactivas de Oxígeno/metabolismo , Ratones Endogámicos C57BL , Microambiente Celular/efectos de los fármacos , Ferrocianuros

RESUMEN

Diabetic wounds that do not heal for a long time challenge global healthcare. Mesenchymal stem cell (MSC) therapy has positive significance in promoting diabetic wound healing. However, traditional MSC therapy involves exogenous MSCs, which brings many limitations and unsatisfactory treatment. Moreover, the maintenance of MSC viability and function is difficult because of the high level of reactive oxygen species (ROS) in diabetic wounds. Therefore, we developed a nanofibrous dressing to recruit and protect endogenous MSCs while avoiding the inherent disadvantages of exogenous MSCs. Ceria nanoparticles capable of ROS scavenging are integrated into the nanofibrous dressings, together with Apt19S, a DNA aptamer with affinity and selectivity for MSCs. In addition, the homogenization and freeze-drying technology give the nanofibrous dressings good elasticity, which protects the wound from external pressure. Further experiments in diabetic mice show that the dressing has excellent endogenous MSC recruitment and anti-inflammatory properties, thereby synergistically promoting diabetic wound healing. This study is expected to explore an efficient method of stem cell therapy, providing a new way to construct high-performance wound dressings.

Asunto(s)

Vendajes , Diabetes Mellitus Experimental , Células Madre Mesenquimatosas , Nanofibras , Cicatrización de Heridas , Animales , Cicatrización de Heridas/efectos de los fármacos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Ratones , Nanofibras/química , Diabetes Mellitus Experimental/terapia , Especies Reactivas de Oxígeno/metabolismo , Masculino , Aptámeros de Nucleótidos/química , Elasticidad , Humanos , Cerio

RESUMEN

We present the synthesis and characterisation of three Ce-based metal-organic frameworks (Ce-MOFs) using fumaric acid (Fu), terephthalic acid (BDC), and trimesic acid (H3BTC) as linkers. The use of different linkers influenced the size of the MOF particles, surface area, crystallinity, and microporous structure. The successful implementation of Ce-Fu, Ce-BDC, and Ce-H3BTC MOFs for fluoride ion removal from wastewater was carried out, in which Ce-Fu MOFs exhibited a maximum adsorption capacity (AC) of 64.2 mg g-1. The study also reveals that the use of ultrasound as a mediator for adsorption study over conventional method gives rapid adsorption rate, in which 85% of the fluoride uptake took place just in 10 min and achieved maximum AC in 30 min. The kinetics data were most accurately explained by the pseudo-second-order model (PSO). The existence of co-ions such as NO3-, Cl-, HCO3-, SO42-, Br-, CO32-, and PO43- has a substantial effect on fluoride removal. The mechanism between the fluoride ions and the MOF surface took place via the electrostatic force and the ion exchange process, confirmed using X-ray photoelectron spectroscopy (XPS) and delsa nano. The material is sustained its relatively higher F- ions removal efficiency up to the five cycles. This research might help in the development of novel microporous Ce-based MOFs since it possesses a highly stable crystalline structure in water, suggesting a promising role in aqueous applications.

Asunto(s)

Cerio , Fluoruros , Estructuras Metalorgánicas , Adsorción , Estructuras Metalorgánicas/química , Fluoruros/química , Cinética , Cerio/química , Ácidos Ftálicos/química , Contaminantes Químicos del Agua/química , Ligandos

RESUMEN

Low concentrations of nitrate (NO3-) widely exist in wastewater, post-treated wastewater, and natural environments; its further disposal is a challenge but meaningful for its discharge goals. Electroreduction of NO3- is a promising method that allows to eliminate NO3- and even generate higher-value NH3. However, the massive side reaction of hydrogen evolution has raised great obstacles in the electroreduction of low concentrations of NO3-. Herein, we present an efficient electroreduction method for low or even ultralow concentrations of NO3- via NO3- self-enrichment and active hydrogen (H*) inducement on the Ce(IV)-Co3O4 cathode. The key mechanism is that the strong oxytropism of Ce(IV) in Co3O4 resulted in two changes in structures, including loose nanoporous structures with copious dual adsorption sites of Ce-Co showing strong self-enrichment of NO3- and abundant oxygen vacancies (Ovs) inducing substantial H*. Ultimately, the bifunctional role synergistically promoted the selective conversion of NH3 rather than H2. As a result, Ce(IV)-Co3O4 demonstrated a NO3- self-enrichment with a 4.3-fold up-adsorption, a 7.5-fold enhancement of NH3 Faradic efficiency, and a 93.1% diminution of energy consumption when compared to Co3O4, substantially exceeding other reported electroreduction cathodes for NO3- concentrations lower than 100 mg·L-1. This work provides an effective treatment method for low or even ultralow concentrations of NO3-.

Asunto(s)

Electrodos , Nitratos , Nitratos/química , Hidrógeno/química , Cerio/química

RESUMEN

Currently the prevalence of diabetic wounds brings a huge encumbrance onto patients, causing high disability and mortality rates and a major medical challenge for society. Therefore, in this study, we are targeting to fabricate aloe vera extract infused biocompatible nanofibrous patches to facilitate the process of diabetic wound healing. Additionally, clindamycin has been adsorbed onto the surface of in-house synthesized ceria nanoparticles and again used separately to design a nanofibrous web, as nanoceria can act as a good drug delivery vehicle and exhibit both antimicrobial and antidiabetic properties. Various physicochemical characteristics such as morphology, porosity, and chemical composition of the produced nanofibrous webs were investigated. Bacterial growth inhibition and antibiofilm studies of the nanofibrous materials confirm its antibacterial and antibiofilm efficacy against Gram-positive and Gram-negative bacteria. An in vitro drug release study confirmed that the nanofibrous mat show a sustained drug release pattern (90% of drug in 96 h). The nanofibrous web containing drug loaded nanoceria not only showed superior in vitro performance but also promoted greater wound contraction (95 ± 2%) in diabetes-induced mice in just 7 days. Consequently, it efficaciously lowers the serum glucose level, inflammatory cytokines, oxidative stress, and hepatotoxicity markers as endorsed by various ex vivo tests. Conclusively, this in-house-fabricated biocompatible nanofibrous patch can act as a potential medicated suppository that can be used for treating diabetic wounds in the proximate future.

Asunto(s)

Aloe , Antibacterianos , Vendajes , Cerio , Diabetes Mellitus Experimental , Nanofibras , Extractos Vegetales , Cicatrización de Heridas , Cerio/química , Cerio/farmacología , Animales , Ratones , Antibacterianos/química , Antibacterianos/farmacología , Cicatrización de Heridas/efectos de los fármacos , Nanofibras/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Aloe/química , Diabetes Mellitus Experimental/tratamiento farmacológico , Poliuretanos/química , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Polietilenglicoles/química , Ensayo de Materiales , Tamaño de la Partícula , Pruebas de Sensibilidad Microbiana , Nanopartículas/química , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Hipoglucemiantes/administración & dosificación , Masculino , Bacterias Gramnegativas/efectos de los fármacos

RESUMEN

The long-term operation feature of enzymatic biofuel cell-based self-powered biosensor (EBFC-SPB) endows them with the potential to execute dual-signal biosensing without having to integrate an extra signal acquisition device. Herein, cobalt and manganese codoped CeO2 nanospheres (CoMn-CeO2 NSs) with glucose-oxidase-like and peroxidase-like activities have been developed as substrate-switched dual-channel signal transduction components in EBFC-SPB for a dual-signal assay of aflatoxin B1 (AFB1). The CoMn-CeO2 NSs modified with aptamer are anchored to a complementary DNA-attached bioanode of EBFC-SPB by base complementary pairing, which catalyze the glucose oxidation together with the glucose oxidase (GOx) on the bioanode. Once the AFB1 appears, CoMn-CeO2 NSs will be released from the bioanode due to the binding specificity of the aptamer, resulting in a decreased catalytic efficiency and the first declining stage of EBFC-SPB. Accompanied by the introduction of H2O2, the residual CoMn-CeO2 NSs on the bioanode switch to peroxidase-like activity and mediate the production of benzo-4-chlorohexadienone (4-CD) precipitate, which increases the steric hindrance and yields another declining stage of EBFC-SPB. By assessing the variation amplitudes during these two declining stages, the dual-signal assay of AFB1 has been realized with satisfying results. This work not only breaks ground in dual-signal bioassays but also deepens the application of nanozymes in EBFC-SPB.

Asunto(s)

Aflatoxina B1 , Técnicas Biosensibles , Cerio , Técnicas Electroquímicas , Nanosferas , Aflatoxina B1/análisis , Aflatoxina B1/metabolismo , Nanosferas/química , Técnicas Biosensibles/métodos , Cerio/química , Glucosa Oxidasa/metabolismo , Glucosa Oxidasa/química , Cobalto/química , Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/metabolismo , Manganeso/química

RESUMEN

The considerable challenge of wound healing remains. In this study, we fabricated a novel multifunctional core-shell nanofibrous scaffold named EGF@BSP-CeO2/PLGA (EBCP), which is composed of Bletilla striata polysaccharide (BSP), Ceria nanozyme (CeO2) and epidermal growth factor (EGF) as the core and poly(lactic-co-glycolic acid) (PLGA) as the shell via an emulsion electrospinning technique. An increase in the BSP content within the scaffolds corresponded to improved wound healing performance. These scaffolds exhibited increased hydrophilicity and porosity and improved mechanical properties and anti-UV properties. EBCP exhibited sustained release, and the degradation rate was <4 % in PBS for 30 days. The superior biocompatibility was confirmed by the MTT assay, hemolysis, and H&E staining. In addition, the in vitro results revealed that, compared with the other groups, the EBCP group presented excellent antioxidant and antibacterial effects. More importantly, the in vivo results indicated that the wound closure rate of the EBCP group reached 94.0 % on day 10 in the presence of H2O2. The results demonstrated that EBCP could comprehensively regulate the wound microenvironment, possess hemostatic abilities, and significantly promote wound healing. In conclusion, the EBCP is promising for facilitating the treatment of infected wounds and represents a potential material for clinical applications.

Asunto(s)

Nanofibras , Orchidaceae , Polisacáridos , Andamios del Tejido , Cicatrización de Heridas , Cicatrización de Heridas/efectos de los fármacos , Nanofibras/química , Polisacáridos/química , Polisacáridos/farmacología , Animales , Andamios del Tejido/química , Orchidaceae/química , Cerio/química , Cerio/farmacología , Ratones , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Antibacterianos/farmacología , Antibacterianos/química , Antioxidantes/farmacología , Antioxidantes/química , Factor de Crecimiento Epidérmico/farmacología , Ratas , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Masculino , Porosidad , Humanos

RESUMEN

The flattened bamboo board (FB) represents a promising innovation in the bamboo industry. To address the challenges of flammability and hygroscopicity, composite coatings consisting of melamine (MEL), phytic acid (PA), cerium ions (Ce3+), and sodium laurate (La) are assembled on the FB surface through an in-situ impregnation strategy. The resulting MEL/PA-Ce3+@La FB exhibits exceptional flame retardancy. It achieves a V-0 rating in the vertical burning test (UL-94) and boasts a high limiting oxygen index (LOI) value of 38.5 %. The coated FB exhibits superhydrophobicity, evidenced by a water contact angle of 156.5°, which can be attributed to the in-situ growth of PA-Ce3+ complexes (for constructing micro/nanoscale coarse structures) and the modification with La (for reducing surface energy).This superhydrophobic surface imparts both self-cleaning and anti-mold properties to the coated FB. Moreover, the coated FB exhibits excellent mechanical stability, withstanding 36 cycles of sandpaper abrasion and tape peeling without losing its hydrophobicity. In summary, this work provides an innovative strategy for the bamboo processing industry to produce flattened bamboo boards with combined flame retardancy, superhydrophobic and anti-mold properties. Such versatility holds significant potential to facilitate the utilization of flattened bamboo boards in the construction and decorative materials industries.

Asunto(s)

Retardadores de Llama , Interacciones Hidrofóbicas e Hidrofílicas , Retardadores de Llama/análisis , Triazinas/química , Propiedades de Superficie , Ácido Fítico/química , Agua/química , Cerio/química , Humectabilidad

RESUMEN

Cardiovascular diseases pose a significant global health challenge, contributing to high mortality rates and impacting overall well-being and quality of life. Nitric oxide (NO) plays a pivotal role as a vasodilator, regulating blood pressure and enhancing blood flow-crucial elements in preventing cardiovascular diseases, making it a prime therapeutic target. Herein, metal-based nanozymes (NZs) designed to induce NO release from both endogenous and exogenous NO-donors are investigated. Successful synthesis of gold, platinum (Pt) and cerium oxide NZs is achieved, with all three NZs demonstrating the ability to catalyze the NO release from various NO sources, namely S-nitrosothiols and diazeniumdiolates. Pt-NZs exhibit the strongest performance among the three NZ types. Further exploration involved investigating encapsulation and coating techniques using poly(lactic-co-glycolic acid) nanoparticles as experimental carriers for Pt-NZs. Both strategies showed efficiency in serving as platforms for Pt-NZs, successfully showing the ability to trigger NO release.

Asunto(s)

Cerio , Oro , Óxido Nítrico , Platino (Metal) , S-Nitrosotioles , Cerio/química , Cerio/farmacología , Óxido Nítrico/metabolismo , Óxido Nítrico/química , Oro/química , Platino (Metal)/química , Platino (Metal)/farmacología , S-Nitrosotioles/química , S-Nitrosotioles/farmacología , Compuestos Azo/química , Compuestos Azo/farmacología , Nanopartículas del Metal/química , Catálisis , Tamaño de la Partícula , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Donantes de Óxido Nítrico/química , Donantes de Óxido Nítrico/farmacología