RESUMEN

Background: Challenges such as poor drug selectivity, non-target reactivity, and the development of drug resistance continue to pose significant obstacles in the clinical application of cancer therapeutic drugs. To overcome the limitations of drug resistance in chemotherapy, a viable treatment strategy involves designing multifunctional nano-platforms that exploit the unique physicochemical properties of tumor microenvironment (TME). Methods: Herein, layer-by-layer nanoparticles with polyporous CuS as delivery vehicles, loaded with a sonosensitizer (tetra-(4-aminophenyl) porphyrin, TAPP) and sequentially functionalized with pH-responsive CaCO3, targeting group hyaluronic acid (HA) were designed and synthesized for synergistic treatment involving chemodynamic therapy (CDT), sonodynamic therapy (SDT), photothermal therapy (PTT), and calcium overload. Upon cleavage in an acidic environment, CaCO3 nanoparticles released TAPP and Ca2+, with TAPP generating 1O2 under ultrasound trigger. Exposed CuS produced highly cytotoxic ·OH in response to H2O2 and also exhibited a strong PTT effect. Results: CuS@TAPP-CaCO3/HA (CTCH) delivered an enhanced ability to release more Ca2+ under acidic conditions with a pH value of 6.5, which in situ causes damage to HeLa mitochondria. In vitro and in vivo experiments both demonstrated that mitochondrial dysfunction greatly amplified the damage caused by reactive oxygen species (ROS) to tumor, which strongly confirms the synergistic effect between calcium overload and reactive oxygen therapy. Conclusion: Collectively, the development of CTCH presents a novel therapeutic strategy for tumor treatment by effectively responding to the acidic TME, thus holding significant clinical implications.

Asunto(s)

Carbonato de Calcio , Calcio , Nanopartículas , Microambiente Tumoral , Humanos , Animales , Nanopartículas/química , Calcio/química , Carbonato de Calcio/química , Carbonato de Calcio/farmacología , Microambiente Tumoral/efectos de los fármacos , Células HeLa , Especies Reactivas de Oxígeno/metabolismo , Ratones , Ácido Hialurónico/química , Porfirinas/química , Porfirinas/farmacología , Porfirinas/farmacocinética , Porfirinas/administración & dosificación , Terapia Fototérmica/métodos , Concentración de Iones de Hidrógeno , Terapia por Ultrasonido/métodos , Neoplasias/terapia , Neoplasias/tratamiento farmacológico , Mitocondrias/efectos de los fármacos , Antineoplásicos/química , Antineoplásicos/farmacología , Ratones Endogámicos BALB C , Ratones Desnudos , Nanopartículas Capa por Capa

RESUMEN

Conventional wound dressings are monolithically designed to cover the injured areas as well as absorb the exudates at injured site. Furthermore, antibacterial drugs and growth prompting factors are additionally appended to realize sensible and omnibearing wound management, exhibiting long and tedious treatment process in practice. Consequently, the creation of multifunctional wound dressings that combines wound repair enhancement with antibacterial properties turns out to be significant for simplifying wound managements. In our investigation, electronegative human epidermal growth factor (hEGF) was combined with the positively charged Zn-Al layered double hydroxides (Zn-Al LDHs) via electrostatic interaction while the obtained hEGF/LDH was integrated with sodium hyaluronate hydrogel (SH) hydrogel, forming a composite hydrogel with synergistic benefits for wound management. The innovative hEGF/LDH@SH hydrogel equipped with fine biocompatibility was designed to optimize wound healing in which hEGF stimulates epithelial cell growth while LDH released antibacterial factor Zn2+ against Methicillin-resistant staphylococcus aureus (MRSA) and Escherichia coli (E.coli) under acidic wound environment. Additionally, the SH hydrogel constructed a three-dimensional structure that not only safeguarded the wound area but also maintained a moist environment conducive to recovery. The synthesized hEGF/LDH was confirmed via fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and thermo-gravimetry (TG) measurements. The release of Zn2+ from Zn-Al LDH under acid circumstance was detected via inductively coupled plasma (ICP) and the in vitro bactericidal experiments endowed the antibacterial property of hEGF/LDH@SH hydrogel. In vitro drug release experiments illustrated the controlled-release of hEGF from hEGF/LDH which promoted the long-term affect of hEGF at wound site. In vitro cell experiments verified that the hEGF/LDH@SH hydrogel motivated the promotion on cell proliferation and migration without cytotoxicity. An in vivo study of the repairing of MRSA-infected wound in mice indicated that hEGF/LDH@SH hydrogel serves as a simple and novel, innoxious and efficient wound healing approach. This brand new hydrogel possesses properties of promoting the regeneration of skin tissue, achieving antimicrobial therapy without any accessional antibacterial drugs as well as realizing controlled release of hEGF.

Asunto(s)

Antibacterianos , Ácido Hialurónico , Hidrogeles , Staphylococcus aureus Resistente a Meticilina , Cicatrización de Heridas , Cicatrización de Heridas/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Ácido Hialurónico/química , Ácido Hialurónico/farmacología , Hidrogeles/química , Hidrogeles/farmacología , Animales , Ratones , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Humanos , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Factor de Crecimiento Epidérmico/farmacología , Factor de Crecimiento Epidérmico/química , Pruebas de Sensibilidad Microbiana , Zinc/química , Zinc/farmacología , Concentración de Iones de Hidrógeno

RESUMEN

Sonodynamic therapy (SDT), a tumor treatment modality with high tissue penetration and low side effects, is able to selectively kill tumor cells by producing cytotoxic reactive oxygen species (ROS) with ultrasound-triggered sonosensitizers. N-type inorganic semiconductor TiO2 has low ROS quantum yields under ultrasound irradiation and inadequate anti-tumor activity. Herein, by using atomic layer deposition (ALD) to create a heterojunction between porous TiO2 and CoOx, the sonodynamic therapy efficiency of TiO2 can be improved. Compared to conventional techniques, the high controllability of ALD allows for the delicate loading of CoOx nanoparticles into TiO2 pores, resulting in the precise tuning of the interfaces and energy band structures and ultimately optimal SDT properties. In addition, CoOx exhibits a cascade of H2O2→O2→·O2 - in response to the tumor microenvironment, which not only mitigates hypoxia during the SDT process, but also contributes to the effect of chemodynamic therapy (CDT). Correspondingly, the synergistic CDT/SDT treatment is successful in inhibiting tumor growth. Thus, ALD provides new avenues for catalytic tumor therapy and other pharmaceutical applications.

Asunto(s)

Peróxido de Hidrógeno , Nanopartículas , Humanos , Especies Reactivas de Oxígeno , Catálisis , Hipoxia

RESUMEN

The development of nanoparticles capable of inducing reactive oxygen species (ROS) formation has become an important strategy for cancer therapy. Simultaneously, the preparation of multifunctional nanoparticles that respond to the tumor microenvironment is crucial for the diagnosis and treatment of tumors. In this study, we designed a Molybdenum disulfide (MoS2) core coated with Manganese dioxide (MnO2), which possessed a good photothermal effect and could produce Fenton-like Mn2+ in response to highly expressed glutathione (GSH) in the tumor microenvironment, thereby generating a chemodynamic therapy (CDT). The nanoparticles were further modified with Methoxypoly(Ethylene Glycol) 2000 (mPEG-NH2) to improve their biocompatibility, resulting in the formation of MoS2@MnO2-PEG. These nanoparticles were shown to possess significant Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) imaging capabilities, making them useful in tumor diagnosis. In vitro and in vivo experiments demonstrated the antitumor ability of MoS2@MnO2-PEG, with a significant killing effect on tumor cells under combined treatment. These nanoparticles hold great potential for CDT/photothermal therapy (PTT) combined antitumor therapy and could be further explored in biomedical research.

RESUMEN

Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, with ineffective treatment and poor prognosis. It is in great demand to develop a novel theranostic strategy for accurate diagnosis and targeted treatment of TNBC. In the present study, one nanoplatform (HA-ICG-Fe-PDA), endowed with multimodal imaging-guided chemodynamic/photodynamic/photothermal (CDT/PDT/PTT) synergistic therapy capacity toward TNBC, was innovatively constructed. The nanoplatform was prepared by covalently conjugating ICG-decorated hyaluronic acid (HA) on Fe3+-chelated polydopamine (PDA). HA facilitated the targeting and accumulating of the nanoplatform in tumor tissue and cells of TNBC, thus producing enhanced magnetic resonance signal. Upon entering into TNBC cells, the intracellular hyaluronidase-catalyzed cleavage of HA-ICG-Fe-PDA activated the prequenched near-infrared (NIR) fluorescence signal, allowing for the activatable NIR fluorescence imaging. On the other hand, Fe3+ in the nanoplatform could be reduced to reactive Fe2+ in tumor microenvironment, guaranteeing efficient Fenton reaction-mediated CDT. The combination of ICG with Fe-PDA enhanced the NIR absorption of the nanoplatform so that considerable PTT/PDT and photothermal imaging were achieved under 808 nm laser irradiation. In vitro and in vivo experiments have verified that the proposed nanoplatform integrates the potential of TNBC-targeting, precise NIR fluorescence/magnetic resonance/photothermal trimodal imaging, efficient treatment via synergistic CDT/PDT/PTT, as well as excellent biocompatibility. Therefore, this multifunctional nanoplatform provides a simple and versatile strategy for imaging-guided theranostics of TNBC.

Asunto(s)

Nanopartículas , Fotoquimioterapia , Neoplasias de la Mama Triple Negativas , Humanos , Neoplasias de la Mama Triple Negativas/diagnóstico por imagen , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Terapia Fototérmica , Línea Celular Tumoral , Fototerapia , Fotoquimioterapia/métodos , Nanomedicina Teranóstica , Microambiente Tumoral

RESUMEN

The hypoxia-activated and nitroreductase-responsive phototheranostic probe has been developed by incorporating a nitro group into a hemicyanine fluorophore. The probe displays extremely sensitive and selective near-infrared fluorescence enhancement to nitroreductase with the detection limit of 2.10 ng/mL. The detection mechanism relies on the nitroreductase-catalyzed reduction of the nitro group to an amino group, along with the generation of the fluorophore. The availability of the probe in fluorescence imaging and photodynamic therapy was demonstrated at cellular level and in vivo. The probe can image endogenous nitroreductase and the hypoxia status of living cells. The probe also exhibits significant phototoxicity to hypoxia tumor cells under the 660 nm laser irradiation. More importantly, the probe has been successfully utilized in imaging tiny tumor (about 6 mm3) and tumor photodynamic therapy in vivo. The proposed probe integrates accurate near-infrared fluorescence imaging and photodynamic therapy into the same molecule, which probably become a promising agent in the early diagnosis and therapy of tumors.

Asunto(s)

Fotoquimioterapia , Colorantes Fluorescentes , Microscopía Fluorescente , Nitrorreductasas , Imagen Óptica

RESUMEN

For the past few years, organic-inorganic hybrid nanocarriers have been widely explored for effective drug delivery and preferable disease treatments. In this article, hydrothermal method was utilized to prepare fine dispersed layered double hydroxide (Mg-Al LDH) suspension. Polyethylene glycol (PEG) was grafted on the surface of LDH lamella in order to improve the dispersibility of LDH. Besides, the anti-cancer drug gemcitabine was grafted on the surface of LDH lamellas through chemical grafting. Hence a novel new type of organic-inorganic hybrid drug delivery system LDH-mPEG-Gemcitabine was obtained. In addition, the siRNA was intercalated into the LDH interlamination by ion exchange method to realize drug and gene co-delivery. The loading capacity of LDH and LDH-mPEG-Gemcitabine was evaluated by agarose gel electrophoresis. The characterization by laser particle size analyzer, TEM, FT-IR, XRD, in vitro cell viability and in vitro drug release demonstrated that LDH-mPEG-Gemcitabine possessed fine dispersibility, uniform morphology and particle size, fine biocompatibility, ideal drug loading and releasing capacity and held great potential to be used as a desired co-delivery system for drug and gene.

Asunto(s)

Hidróxidos , Polietilenglicoles , Desoxicitidina/análogos & derivados , Sistemas de Liberación de Medicamentos , Espectroscopía Infrarroja por Transformada de Fourier , Gemcitabina

RESUMEN

The incidence of breast cancer, one of the most common malignancies affecting women, is increasing significantly worldwide. Given the rapid development of medical technology, early and effective diagnostic methods should be able to improve the survival rate and quality of life of patients suffering from disease. However, although existing treatment options, including chemotherapy and endocrine therapies, have greatly improved the survival of patients, disease recurrence in the long term remains a challenge. Because breast cancer is a heterogeneous and complex disease, which includes several subtypes with different responses to treatment, the continual acquisition of spatial information on related biomolecules is important for accurate tracking of the tumor heterogeneity and microenvironment. At present, prognostic and predictive biomarkers, such as human epidermal growth factor receptor 2 (HER2), estrogen receptor (ER), Ki-67, progesterone receptor (PR), and programmed death-ligand 1 (PD-L1), are validated for use in the decision-making over breast cancer therapies. Mass spectrometry imaging (MSI) is a useful technique for acquiring molecular information about biological tissues, including qualitative, quantitative, and spatial distribution information, because it is based on the ion mass-to-charge ratio of the biomolecules and avoids the need for their labeling and staining. MSI can also acquire molecular information on drugs and their metabolites, as well as that on molecules related to endogenous metabolism, such as lipids, peptides, and proteins. Of the various ion sources available for MSI, the most popular are matrix-assisted laser desorption ionization, secondary ion mass spectrometry, and desorption electrospray ionization, and modifications or derivatives of these sources are still emerging. MSI-based techniques provide new ideas and directions for the molecular typing of tumors, as well as knowledge on the metabolism of related antitumor drugs. The process of MSI analysis generally involves tissue acquisition, section preparation, mass spectrometry ionization, map acquisition, and data analysis, with the most crucial step being sample handling to preserve the original chemical and location information of the analytes. The sample preparation steps are sample collection, storage, and slicing, tissue pretreatment, and matrix spraying. This review focuses mainly on the preparation of biological specimens for MSI analysis and the recent progress made in breast cancer research with this technology. With regard to sample preparation, four aspects are discussed: small-molecule samples, macromolecular samples, paraffin-embedded samples, and matrix spraying methods. To solve the difficulties associated with small-molecule sample processing, including the low extraction efficiency for certain lipids and matrix interference in the low-molecular-weight region, the addition of a cationic reagent to the extractant, the use of a new matrix, and tissue derivatization have been used. In the review of macromolecular sample processing, several different washing protocols are summarized. With regard to paraffin-embedded samples, the solutions to several common problems are reviewed. Additionally, the application of MSI to three models associated with breast cancer research is discussed, viz. cell models, animal models, and clinical tumor samples. For these models, MSI technology is used to evaluate the penetration and metabolism of antitumor agents in breast cancer, which can better reflect the malignant transformation of cells and changes in the microenvironment. With regard to lipid molecules, the use of MSI to study differences in their spatial distribution may provide a better understanding of the relationship between lipid metabolism and cancer. This review also provides important information for accurate molecular typing and drug screening in cancer research. Analytically, the tissue preparation method, tissue storage conditions, instrumentation choice, and experimental parameters have all been associated with variability in the imaging and mass-spectral qualities of MSI, thereby affecting the performance of the method. Large-scale studies using diverse sample cohorts are therefore needed to properly evaluate the robustness of MSI molecular markers and workflows for the clinical diagnosis and characterization of breast cancer variants. Our review provides strong evidence that MSI is a reliable, highly reproducible, and rapid technique for the diagnosis of breast cancer biopsies and may be useful in clinical application.

Asunto(s)

Neoplasias de la Mama , Espectrometría de Masas/métodos , Animales , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/tratamiento farmacológico , Femenino , Humanos , Calidad de Vida , Tecnología , Microambiente Tumoral

RESUMEN

The first ultrafast fluorescence probe with response time in seconds (10 s) for fluoride ions (F-) has been proposed by conjugating dimethylthiophosphoryl group as a recognition unit with the near-infrared fluorophore of hemicyanine. The response mechanism is the F--induced cleavage of the dimethylthiophosphoryl group, along with the liberation of the fluorophore, which results in a distinctly enhanced fluorescence intensity at 730 nm (λex = 680 nm). The fluorescence enhancement of the probe is directly proportional to the F- concentration in the range of 10-300 µM with the detection limit of 4.28 µM. The probe has been successfully used to determine F- concentration in real water and toothpaste samples as well as image F- in living cells. The simplicity and quick response of this probe endow it with the ability of detecting F- rapidly in real samples.

Asunto(s)

Colorantes Fluorescentes , Fluoruros , Fluorescencia , Flúor , Agua

RESUMEN

Metabolites of methionine cycle, urea cycle and polyamine metabolism play important roles in regulating the metabolic processes and the development of diseases. It is rewarding and interesting to monitor the levels of the above metabolites in biological matrices to investigate pathological mechanisms. However, their quantitation is still unsatisfactory due to the poor retention behavior of the analytes on the traditional reversed-phase column. And never a single analytical method simultaneously quantify these three classes of metabolites. Besides, the concentrations of some metabolites are too low to be detected in the biological samples. In this study, we developed a UHPLC-ESI-MS/MS method to simultaneously determine the levels of 14 metabolites, including 4 methionine metabolism metabolites (methionine, homocysteine, S-adenosylmethionine and S-adenosylhomocysteine), 3 urea cycle intermediates (arginine, citrulline and ornithine) and 7 polyamines (putrescine, spermidine, spermine, N1-acetylputrescine, N1-acetylspermidine, N1-acetylspermine and N1,N12-diacetylspermine). The chromatographic separation was performed on the BEH amide column within 14 min using water and acetonitrile (both with 0.1% formic acid) as the mobile phases. The results of method validation showed good selectivity, linearity (r2 > 0.99), recovery (93.1%-112.1%), inter-day and intra-day precision (RSD < 13.6% and RSD < 11.0%, respectively), stability (RSD < 15.1%) and matrix effect (76.0%-113.2%). The method is simple, quick and sensitive without derivatization processes and the use of ion-pairing reagents. This approach was successfully applied in urine, serum and tissue matrices, as well as in identifying potential biomarkers for hyperthyroidism and hypothyroidism. The method is promising to provide more information on pathophysiological mechanisms in metabolomics study.

Asunto(s)

Poliaminas , Espectrometría de Masas en Tándem , Cromatografía Líquida de Alta Presión , Metionina , Reproducibilidad de los Resultados , Urea

RESUMEN

A transferrin receptor (TfR)-targeted nanodrug [green fluorescence emission carbon dot (GCD)-polyethylene glycol (PEG)-transferrin (Tf)@doxorubicin (Dox)] for cancer therapy was developed by functionalizing GCDs with PEG, Tf, and Dox. GCDs were synthesized by the one-step hydrothermal method, followed by conjugating PEG and Tf by covalent bonds and loading Dox by electrostatic interactions. The nanodrug exhibits high stability under neutral conditions and effectively releases Dox at pH of 5.5. GCD-PEG-Tf@Dox can be selectively internalized by TfR-overexpressed tumor cells (MCF-7 and K150) via receptor-mediated endocytosis and further release Dox to the nuclei. As a result, GCD-PEG-Tf@Dox exhibits significant lethality to tumor cells (MCF-7 and K150) but greatly reduced toxicity to normal cells [Chinese hamster ovary cell line (CHO)] compared with free Dox. In vivo studies have confirmed that GCD-PEG-Tf@Dox can effectively inhibit tumor proliferation with negligible side effects.

Asunto(s)

Neoplasias , Transferrina , Animales , Células CHO , Carbono/metabolismo , Línea Celular Tumoral , Cricetinae , Cricetulus , Doxorrubicina/farmacología , Sistemas de Liberación de Medicamentos/métodos , Neoplasias/tratamiento farmacológico , Polietilenglicoles/química , Transferrina/química

RESUMEN

Herein, nitrogen-doped carbon dots (N-CDs) emitting blue fluorescence were prepared using L-tartaric acid and triethylenetetramine through a simple and quick microwave-assisted method. The synthesized N-CDs displayed excitation-dependent fluorescence behavior, and their maximum excitation and emission wavelengths were 350 and 425 nm, respectively. The obtained N-CDs, which featured excellent fluorescence properties with a high fluorescence quantum yield of 31%, were applied to detect metronidazole (MNZ), which can effectively quench the fluorescence intensity of N-CDs due to the inner filter effect. This phenomenon was used as basis to develop a label-free fluorescent method for rapid MNZ determination, with the limit of detection of 0.22 µM and corresponding linear range of 0.5-22 µM. Hence, we had established a fluorescence method for MNZ detection and applied it to detect MNZ in real samples with satisfactory results. Finally, N-CDs with superior biocompatibility were applied for cell imaging and MNZ detection by the changes in fluorescence intensity.

Asunto(s)

Carbono/química , Metronidazol/análisis , Nitrógeno/química , Imagen Óptica , Puntos Cuánticos/química , Animales , Muerte Celular , Supervivencia Celular , Humanos , Células MCF-7 , Leche/química , Espectroscopía de Fotoelectrones , Puntos Cuánticos/ultraestructura , Espectrometría de Fluorescencia

RESUMEN

A highly sensitive and selective fluorescent probe for fluoride ions has been developed by incorporating the dimethylphosphinothionyl group as a recognition moiety into the fluorophore of coumarin. The detection mechanism is based on the fluoride ion-triggered cleavage of the dimethylphosphinothionyl group, followed by the release of coumarin, which leads to a large fluorescence enhancement at 455 nm (λ ex = 385 nm). Under the optimized conditions, the fluorescence enhancement of the probe is directly proportional to the concentration of fluoride ions in the range of 0-30 µM with a detection limit of 0.29 µM, which is much lower than the maximum content of fluoride ions guided by WHO. Notably, satisfying results have been obtained by utilizing the probe to determine fluoride ions in real-water samples and commercially available toothpaste samples. The proposed probe is rather simple and may be useful in the detection of fluoride ions in more real samples.

RESUMEN

A rapid method has been developed for the determination of Hg(II) and sulfide by using graphitic carbon nitride quantum dots (g-CNQDs) as a fluorescent probe. The interaction between Hg(II) and g-CNQDs leads to the quenching of the blue g-CNQD fluorescence (with excitation/emission peaks at 390/450 nm). However, the fluorescence can be recovered after addition of sulfide such that the "turn-off" state is switched back to the "turn-on" state. The g-CNQDs were fully characterized by transmission electron microscopy, X-ray diffractometry, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, UV-vis absorption and fluorescence spectroscopy. Under the optimal experimental conditions, this probe is highly selective and sensitive to Hg(II). The linear response to Hg(II) extends from 0.20 to 21 µM with a detection limit of 3.3 nM. In addition, sulfide can be detected via the recovery of fluorescence. The linear response range for sulfide species is from 8.0 to 45 µM with a detection limit of 22 nM. The mechanism of the "turn-off-on" scheme is discussed. The methods have been applied to the analysis of spiked tap water, lake water and wastewater samples. Graphical abstract Schematic of an off-on fluorescent probe for mercury(II). The fluorescence of graphitic carbon nitride quantum dots (g-CNQDs) is quenched by Hg2+ but is recovered after reacting with S2- as it can combine with Hg2+ on the surface of g-CNQDs.

RESUMEN

A facile and efficient strategy is presented for the encapsulation of Ag NPs within hierarchical porous silicalite-1. The physicochemical properties of the resultant catalyst are characterized by TEM, XRD, FTIR, and N2 adsorption-desorption analytical techniques. It turns out that the Ag NPs are well distributed in MFI zeolite framework, which possesses hierarchical porous characteristics (1.75, 3.96 nm), and the specific surface area is as high as 243 m2 · g-1. More importantly, such catalyst can rapidly transform the 4-nitrophenol to 4-aminophenol in aqueous solution at room temperature, and a quantitative conversion is also obtained after being reused 10 times. The reasons can be attributed to the fast mass transfer, large surface area, and spatial confinement effect of the advanced support.

RESUMEN

Most carbon dots (CDs) conventional fabrication approaches produce single colored fluorescent materials, different methods are required to synthesize distinct carbon dots for specific optical applications. Herein, using one-pot hydrothermal treatment of Syringa obtata Lindl, a facile, low-cost and green assay is achieved in the controllable synthesis of blue and green fluorescent carbon dots. The fluorescent emission of CDs can be well-tuned by adding sodium hydroxide in the precursor solution. Blue fluorescent CDs are applied to Fe3+ sensing with a low detection limit of 0.11 µM of linear range from 0.5 to 80 µM, and then further extended to analysis river water samples. Green fluorescent CDs can be applied to pH detection, which show a remarkable linear enhancement in the green fluorescence emission region when the pH is increased from 1.98 to 8.95. Eventually, the detection of Fe3+ and pH are applied for the living cells fluorescent images in MCF-7 cells are achieved successfully, indicating as-synthesized CDs potential toward diverse application as promising candidate.

Asunto(s)

Técnicas Biosensibles/métodos , Carbono/química , Células/metabolismo , Tecnología Química Verde/métodos , Imagenología Tridimensional , Puntos Cuánticos/química , Muerte Celular , Fluorescencia , Humanos , Concentración de Iones de Hidrógeno , Iones , Límite de Detección , Células MCF-7 , Puntos Cuánticos/ultraestructura , Ríos/química , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Agua/química

RESUMEN

A novel mercaptotetrazole-silica hybrid monolithic column was prepared for capillary liquid chromatography, in which the thiol-end mercaptotetrazole was mixed with hydrolyzed γ-methacryloxypropyltrimethoxysilane and tetramethyloxysilane for the co-polycondensation and thiol-ene click reaction in a one-pot process. The effects of the molar ratio of silanes, the amount of mercaptotetrazole, and the volume of porogen on the morphology, permeability and pore properties of the as-prepared mercaptotetrazole-silica hybrid monoliths were investigated in detail. A series of test compounds including alkylbenzenes, amides and anilines were employed for evaluating the retention behaviors of the mercaptotetrazole-silica hybrid monolithic columns. The results demonstrated that the mercaptotetrazole-silica hybrid monoliths exhibited hydrophobic, hydrophilic as well as ion-exchange interaction. The run-to-run, column-to-column and batch-to-batch reproducibilities of the mercaptotetrazole-silica hybrid monoliths were satisfactory with the relative standard deviations less than 1.4 (n = 5), 3.9 (n = 3) and 4.0% (n = 5), respectively. In addition, the mercaptotetrazole-silica hybrid monolith was further applied to the separation of sulfonamides, nucleobases and protein tryptic digests. These successful applications confirmed the promising potential of the mercaptotetrazole-silica hybrid monolith in the separation of complex samples.

RESUMEN

A highly enantioselective conjugate addition of 2-substituted benzofuran-3(2H)-ones to α,ß-unsaturated ketones promoted by chiral copper complexes has been developed, affording the Michael addition products with quaternary stereocenters in good to high yields (up to 95% yield) with excellent enantioselectivities (up to 99% ee). The chiral Michael adducts could be readily converted to the polycyclic benzofuran-type framework via the Robinson annulation.

RESUMEN

A potential adsorbent based on betaine-modified magnetic iron oxide nanoparticles (BMNPs) was successfully synthesized by facile method, characterized and applied for methyl blue (MB) removal from aqueous solution. The characterization results of FTIR, transmission electron microscopy (TEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) showed that the prepared nanoparticles could be well dispersed in water and exhibited excellent superparamagnetism. These properties imply the potential to recycle BMNPs from wastewater through magnetic field. In the adsorption process, the effects of main experimental parameters such as pH of MB solution, initial concentration of MB, contact time, and adsorption capacity for MB were studied and optimized. These results demonstrated that large amounts of quaternary ammonium groups existing on the surface of BMNPs could promote absorption of MB via electrostatic forces. Additionally, the adsorption kinetics of MB was found to follow a pseudo-second-order kinetic model and the adsorption equilibrium data fitted very closely to the Langmuir adsorption isotherm model. The maximum adsorption capacity for MB was calculated to be 136mgg-1 at room temperature. Moreover, the BMNPs showed good reusability with 73.33% MB adsorption in the 5th cycle.