RESUMO
Nanoparticles are efficient drug delivery vehicles for targeting specific organs as well as systemic therapy for a range of diseases, including cancer. However, their interaction with the immune system offers an intriguing challenge. Due to the unique physico-chemical properties, carbon nanotubes (CNTs) are considered as nanocarriers of considerable interest in cancer diagnosis and therapy. CNTs, as a promising nanomaterial, are capable of both detecting as well as delivering drugs or small therapeutic molecules to tumour cells. In this study, we coupled a recombinant fragment of human surfactant protein D (rfhSP-D) with carboxymethyl-cellulose (CMC) CNTs (CMC-CNT, 10-20 nm diameter) for augmenting their apoptotic and immunotherapeutic properties using two leukemic cell lines. The cell viability of AML14.3D10 or K562 cancer cell lines was reduced when cultured with CMC-mwCNT-coupled-rfhSP-D (CNT + rfhSP-D) at 24 h. Increased levels of caspase 3, 7 and cleaved caspase 9 in CNT + rfhSP-D treated AML14.3D10 and K562 cells suggested an involvement of an intrinsic pathway of apoptosis. CNT + rfhSP-D treated leukemic cells also showed higher mRNA expression of p53 and cell cycle inhibitors (p21 and p27). This suggested a likely reduction in cdc2-cyclin B1, causing G2/M cell cycle arrest and p53-dependent apoptosis in AML14.3D10 cells, while p53-independent mechanisms appeared to be in operation in K562 cells. We suggest that CNT + rfhSP-D has therapeutic potential in targeting leukemic cells, irrespective of their p53 status, and thus, it is worth setting up pre-clinical trials in animal models.
Assuntos
Apoptose/efeitos dos fármacos , Imunoterapia , Leucemia Mieloide Aguda/terapia , Nanotubos de Carbono/química , Proteína D Associada a Surfactante Pulmonar , Humanos , Células K562 , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Proteína D Associada a Surfactante Pulmonar/química , Proteína D Associada a Surfactante Pulmonar/farmacologia , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacologiaRESUMO
Constructing yolk-shell-structured non-noble-metal composites is very important for improving their activity and stability in catalytic performance. Herein, we report a facile strategy for the synthesis of ternary Cu@SiO2@C yolk-shell composites by converting the resorcinol-formaldehyde (RF) resin-coated Cu2O@SiO2 with a core-shell structure via a thermal treatment under a N2 atmosphere. Notably, the annealing temperature and silica interlayer play vital roles in modulating their structures and catalytic performance. Moreover, this strategy may pave a new way to constructing non-noble-metal-based composites with yolk-shell structures.
RESUMO
A robust prediction of U(VI) on Fe3O4/activated carbon (Fe3O4/AC, fabricated by co-precipitation method under N2 conditions) under different pH was developed via diffuse layer model, in accordance with FI-IR, XRD and XPS analysis. No influence of ionic strength onto U(VI) adsorption by Fe3O4/AC under ambient conditions suggested the inner-sphere surface adsorption, which was attributed to abundant surficial functional groups according to FT-IR and XPS analysis. The batch experiments indicated Fe3O4/AC with fast adsorption rate (equilibrium within 60 min), high adsorption capacity (56 mg/g at pH 4.0) towards U(VI). The adsorbed U(VI) was partly reduced by Fe2+ of Fe3O4/AC by XPS analysis. Surface complexation modeling showed that a single set of monodentate and mononuclear species (SOUO2+) cannot predict U(VI) adsorption at high pH, whereas the robust prediction of U(VI) adsorption over wide pH range was observed by adding the other binuclear and tridentate species ((SO)2UO2(CO3)6-). These findings revealed that magnetic AC as a candidate for immobilization and/or preconcentration of radioactive wastewater in environment management.
Assuntos
Urânio , Poluentes Radioativos da Água , Adsorção , Carvão Vegetal , Concentração Osmolar , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Radioativos da Água/análiseRESUMO
A new photocatalyst of TiO2/C3N4 composite (TiO2/g-C3N4) was synthesized by the hydrothermal method. The characterization showed that TiO2/g-C3N4 extended absorption light range and enhanced generation efficiency of photo-induced electron. Under the simulated solar irradiation, the photodegradation rate of bisphenol A (BPA) by TiO2/g-C3N4 was twice as fast as that of g-C3N4. Furthermore, TiO2/g-C3N4 presented the good stability and excellent selectivity for BPA degradation. The high degradation rate of BPA by TiO2/g-C3N4 was demonstrated to be superoxide radical (·O2-) and singlet oxygen (1O2) by radical quenching experiment, which was further evidenced by EPR, XPS, DRS and PL analysis. These findings revealed that TiO2/g-C3N4 can be used as a potential photocatalyst for removing organic pollutants in actual environmental remediation.
Assuntos
Compostos Benzidrílicos , Luz , Fenóis , Compostos Benzidrílicos/química , Catálise , Fenóis/química , Fotólise , TitânioRESUMO
We determine the structure of Leavitt path algebras of polynomial growth and discuss their automorphisms and involutions.
Assuntos
Matemática/métodos , Modelos TeóricosRESUMO
Malaria remains a serious worldwide health danger and massive economic trouble to disease-endemic nations. Presently, 250 million of malarial cases are expected worldwide. The emergence of fighting of the Plasmodium parasite against the first-line antimalarial drugs has fueled research attention in the way of designing new scaffolds as well as strategies to counter the drug resistance. Chalcones are simple and well-known analogs, which were found in a huge number of natural compounds and also been prepared according to their suitable synthetic approaches. This review illustrates the current progresses on structure-activity relationship (SAR) and mechanism of diverse types of chalcone derivatives that play a significant role for the development of novel safe, less toxic and highly active antimalarials. This present mini-review will be useful to scientists in research fields of medicinal chemistry, organic synthesis, and also various biological applications particularly for the development of novel antiplasmodial and antimalarial agents.
Assuntos
Antimaláricos/farmacologia , Chalcona/farmacologia , Descoberta de Drogas , Malária/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Animais , Antimaláricos/síntese química , Antimaláricos/química , Chalcona/síntese química , Chalcona/química , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Relação Estrutura-AtividadeRESUMO
The simultaneously efficient removal of cationic and anionic radionuclides is an important and challenging topic for nuclear waste remediation as well as environmental protection. Herein, monoclinic ZIF-8 nanosheets modified with ethyleneimine polymer (denoted as ZIF-8/PEI) was achieved and used to determine the capture behaviors of both U(VI) oxycations and Re(VII) oxyanions from aqueous solution. ZIF-8/PEI assemblies showed a maximum U(VI) and Re(VII) uptake capacity of 665.3 (pH 5.0) and 358.2 mg/g (pH 3.5), respectively. Experimental, spectroscopic and theoretical calculation results directly unraveled that U(VI) adsorption onto ZIF-8/PEI assemblies was mainly ascribed to the coordination with abundant amino groups and weakly due to the Zn terminal hydroxyl groups, while anion exchange mechanism contributed predominantly to the Re(VII) sequestration. This work not only sheds light on the interaction mechanisms of simultaneous capture of U(VI) and Re(VII) but also highlights the versatile material design of cationic and anionic radionuclide immobilization in radioactive wastewater remediation.
RESUMO
The encapsulation of small non-noble metal nanoparticles (NPs) within an inorganic layer has received considerable attention owing to their enhanced stability and high catalytic activity. Using a combination of emulsion-free polymerization, inner RF-Ni2+ and outer SiO2 coating, and subsequent carbonization treatment, herein, we have fabricated worm-like structured Ni-based composites in which a high density of nickel NPs are embedded in a carbon layer and also entrapped by SiO2 nanocages. We find that the carbonization temperature plays a vital role in adjusting the size of the Ni NPs. A detailed examination of the encapsulated nickel particles synthesized at 700 °C exhibited the best performance on the catalysis of the reduction of 4-NPs. Moreover, owing to the good alloying ability of the Ni NPs with noble metal NPs, the Ni-Pd alloy NPs are also entrapped in the SiO2 nanocages, which exhibit better performance on the catalysis than the Ni-based composites. The encapsulation of Ni-Pd alloys within SiO2 nanocages also improves stability against agglomeration and metal separation during catalytic operation.
RESUMO
A class of novel δ-sulfonolactone-fused pyrazole scaffold was prepared via sulfur (VI) fluoride exchange (SuFEx) chemistry using aryl sulfonyl fluorides and pyrazolones. Enzyme screening revealed their cholinesterase inhibitory activity, among them, compounds 4a, 5a and 5d were identified as highly selective submicromolar BuChE inhibitors (IC50â¯=â¯0.20, 0.46 and 0.42⯵M, respectively), which exhibited nontoxicity, lipophilicity and remarkable neuroprotective activity. Kinetic studies showed that BuChE inhibition of compounds 5a and 5d was reversible, mixed-type and non-competitive inhibition against BuChE (Kiâ¯=â¯145â¯nM and 60â¯nM, respectively). Compound 5d can be accommodated into hBuChE via π-S interaction and hydrophobic interactions. The title compounds are potentially symptomatic treatment in progressive Alzheimer's disease.
Assuntos
Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Pirazóis/química , Pirazóis/farmacologia , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/enzimologia , Inibidores da Colinesterase/síntese química , Desenho de Fármacos , Humanos , Simulação de Acoplamento Molecular , Naftalenossulfonatos/síntese química , Naftalenossulfonatos/química , Naftalenossulfonatos/farmacologia , Pirazóis/síntese química , Relação Estrutura-AtividadeRESUMO
The objective of present research is to examine the thermal radiation effect in three-dimensional mixed convection flow of viscoelastic fluid. The boundary layer analysis has been discussed for flow by an exponentially stretching surface with convective conditions. The resulting partial differential equations are reduced into a system of nonlinear ordinary differential equations using appropriate transformations. The series solutions are developed through a modern technique known as the homotopy analysis method. The convergent expressions of velocity components and temperature are derived. The solutions obtained are dependent on seven sundry parameters including the viscoelastic parameter, mixed convection parameter, ratio parameter, temperature exponent, Prandtl number, Biot number and radiation parameter. A systematic study is performed to analyze the impacts of these influential parameters on the velocity and temperature, the skin friction coefficients and the local Nusselt number. It is observed that mixed convection parameter in momentum and thermal boundary layers has opposite role. Thermal boundary layer is found to decrease when ratio parameter, Prandtl number and temperature exponent are increased. Local Nusselt number is increasing function of viscoelastic parameter and Biot number. Radiation parameter on the Nusselt number has opposite effects when compared with viscoelastic parameter.