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1.
J Cancer Res Clin Oncol ; 146(4): 875-882, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32107624

RESUMEN

PURPOSE: Presently, liver cancer is still one of the malignant tumors with high mortality. As far as the treatment of liver cancer is concerned, the most effective method is still liver transplantation. But every year, many liver cancer patients die from the lack of a proper liver transplant, or from waiting for a liver transplant. Therefore, it is very important to find new and effective treatment for patients with liver cancer. METHODS: Herein, the cell model and the orthotropic liver tumor mice model have been performed to verify the results of our treatment. We found that the in situ synthesized gold nanocluster-PTEN (GNC-PTEN) complexes can effectively target and realize the fluorescence imaging of the liver tumor. RESULTS: GNC-PTEN complexes could inhibit the proliferation, invasion, and metastasis of liver cancer cells. And the results also showed that GNC-PTEN complexes could be well targeted liver tumor at 6 h and the liver tumor in mice group treated with GNC-PTEN complexes almost disappeared. CONCLUSION: This is a simply and effectively method to realize liver cancer imaging and inhibition. This may raise the possibility for the accurate image/diagnosis and simultaneously efficient treatment of liver cancer in the relevant clinic application.


Asunto(s)
Oro/administración & dosificación , Neoplasias Hepáticas/tratamiento farmacológico , Nanopartículas del Metal/administración & dosificación , Fosfohidrolasa PTEN/administración & dosificación , Animales , Oro/química , Células Hep G2 , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/enzimología , Neoplasias Hepáticas/genética , Nanopartículas del Metal/química , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Fosfohidrolasa PTEN/química , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Distribución Aleatoria , Ensayos Antitumor por Modelo de Xenoinjerto
2.
J Agric Food Chem ; 68(9): 2826-2831, 2020 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-32045247

RESUMEN

In this work, we have developed an all-in-one aptasensor based on an enzyme-driven three-dimensional DNA walker for antibiotic detection. To overcome the drawback of time-consuming methods, high-density substrate strands were anchored on the walking interface that accelerated the signal amplification efficiency. Such an all-in-one design integrated the functionality of target recognition, signal amplification, as well as signal output into a single probe. Upon addition of kanamycin, the activated walking strand moved along the track by the stepwise cleavage of a nicking enzyme, which resulted in the enhancement of the fluorescence intensity of the solution. Under the optimized conditions, the detection process was accomplished in 40 min with a low detection limit of 1.23 pM. This aptasensor was also applied in spiked milk samples with satisfactory recoveries of 97.76% to 105.33%, demonstrating an excellent stability and accuracy. Therefore, this all-in-one aptasensor shows great potential for applications in food safety.


Asunto(s)
Antibacterianos/análisis , Técnicas Biosensibles/métodos , Animales , Aptámeros de Nucleótidos/química , Técnicas Biosensibles/instrumentación , Bovinos , Contaminación de Alimentos/análisis , Oro/química , Kanamicina/análisis , Límite de Detección , Leche/química
3.
Phys Chem Chem Phys ; 22(8): 4490-4500, 2020 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-32067002

RESUMEN

Once introduced into the human body, nanoparticles often interact with blood proteins, which in turn undergo structural changes upon adsorption. Although protein corona formation is a widely studied phenomenon, the structure of proteins adsorbed on nanoparticles is far less understood. We propose a model to describe the interaction between human serum albumin (HSA) and nanoparticles (NPs) with arbitrary coatings. Our model takes into account the competition between protonated and unprotonated polymer ends and the curvature of the NPs. To this end, we explored the effects of surface ligands (citrate, PEG-OMe, PEG-NH2, PEG-COOH, and glycan) on gold nanoparticles (AuNPs) and the pH of the medium on structural changes in the most abundant protein in blood plasma (HSA), as well as the impact of such changes on cytotoxicity and cellular uptake. We observed a counterintuitive effect on the ζ-potential upon binding of negatively charged HSA, while circular dichroism spectroscopy at various pH values showed an unexpected pattern in the reduction of α-helix content, as a function of surface chemistry and curvature. Our model qualitatively reproduces the decrease in α-helix content, thereby offering a rationale based on particle curvature. The simulations quantitatively reproduce the charge inversion measured experimentally through the ζ-potential of the AuNPs in the presence of HSA. Finally, we found that AuNPs with adsorbed HSA display lower toxicity and slower cell uptake rates, compared to functionalized systems in the absence of protein. Our study allows examining and explaining the conformational dynamics of blood proteins triggered by NPs and corona formation, thereby opening new avenues toward designing safer NPs for drug delivery and nanomedical applications.


Asunto(s)
Oro/química , Oro/metabolismo , Nanopartículas del Metal/química , Albúmina Sérica Humana/química , Humanos , Enlaces de Hidrógeno , Concentración de Iones de Hidrógeno , Unión Proteica , Estructura Terciaria de Proteína , Albúmina Sérica Humana/metabolismo , Electricidad Estática , Propiedades de Superficie
4.
J Photochem Photobiol B ; 204: 111800, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32028188

RESUMEN

Herein, we have reported the synthesis, characterization and catalytic activity of highly stable gold nanoparticles (Au NPs) using red cabbage extract (RCE) under UV irradiation. The anthocyanin groups predominantly existing in RCE play an essential role for biosynthesis of stable Au NPs. The reasons for using anthocyanins: 1) they act as chelating agents for preferentially reacting with gold ions (Au3+) to form Au3+- anthocyanin complexes, 2) as light-active reductants for reduction of Au3+ to zero valent Au0 under UV irradiation and 3) as stabilizing agent for preventing Au NPs from aggregation in high salt concentration owing to their unique salt tolerance property. We also demonstrate that how reaction time, concentration of RCE, pH value of reaction solutions and using one more reducing agent affected formation of the Au NPs. The stability of RCE Au NPs was comparatively studied with commercial (citrate stabilized) Au NPs against 100 mM salt (NaCl) solution. The RCE-Au NP showed reduction ability for conversion of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). UV-vis spectrometry, transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential (ZT) methods were utilized to characterize the Au NPs. We demonstrated that how whole RCE (anthocyanins molecules are major component) can be used as photo-active reducing and stabilizing agents to form Au NPs in a short time under UV irradiation and strong reducing agent without additional agents.


Asunto(s)
Brassica/química , Oro/química , Nanopartículas del Metal/química , Rayos Ultravioleta , Antocianinas/química , Brassica/metabolismo , Catálisis , Tecnología Química Verde , Nitrofenoles/química , Oxidación-Reducción , Extractos Vegetales/química , Sales (Química)/química
5.
J Phys Chem Lett ; 11(5): 1697-1701, 2020 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-32039604

RESUMEN

Here we demonstrate sub-10 nm spatial resolution sampling of a volume of ∼360 molecules with a strong field enhancement at the sample-tip junction by implementing noble metal substrates (Au, Ag, Pt) in photoinduced force microscopy (PiFM). This technique shows the versatility and robustness of PiFM and is promising for application in interfacial studies with hypersensitivity and super spatial resolution.


Asunto(s)
Metales/química , Microscopía de Fuerza Atómica/métodos , Animales , Bovinos , Oro/química , Platino (Metal)/química , Albúmina Sérica Bovina/química , Dióxido de Silicio/química , Plata/química
6.
J Photochem Photobiol B ; 204: 111812, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32062391

RESUMEN

One of the most important barriers to the detection of the biological autoluminescence (BAL) from biosystems using a non-invasive monitoring approach, in both the in vivo and the in vitro applications, is its very low signal intensity (< 1000 photons/s/cm2). Experimental studies have revealed that the formation of electron excited species, as a result of reactions of biomolecules with reactive oxygen species (ROS), is the principal biochemical source of the BAL which occurs during the cell metabolism. Mitochondria, as the most important organelles involved in oxidative metabolism, are considered to be the main intracellular BAL source. Hence, in order to achieve the BAL enhancement via affecting the mitochondria, we prepared a novel mitochondrial-liposomal nanocarrier with two attractive features including the intra-liposomal gold nanoparticle synthesizing ability and the mitochondria penetration capability. The results indicate that these nanocarriers (with the average size of 131.1 ±â€¯20.1 nm) are not only able to synthesize the gold nanoparticles within them (with the average size of 15 nm) and penetrate into the U2OS cell mitochondria, but they are also able to amplify the BAL signals. Our results open new possibilities for the use of biological autoluminescence as a non-invasive and label-free monitoring method in nanomedicine and biotechnology.


Asunto(s)
Oro/química , Liposomas/química , Nanopartículas del Metal/química , Mitocondrias/metabolismo , Línea Celular Tumoral , Humanos , Liposomas/metabolismo , Microscopía Fluorescente , Especies Reactivas de Oxígeno/metabolismo
7.
Nat Commun ; 11(1): 207, 2020 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-31924755

RESUMEN

Label-free surface-enhanced Raman spectroscopy (SERS) can interrogate systems by directly fingerprinting their components' unique physicochemical properties. In complex biological systems however, this can yield highly overlapping spectra that hinder sample identification. Here, we present an artificial-nose inspired SERS fingerprinting approach where spectral data is obtained as a function of sensor surface chemical functionality. Supported by molecular dynamics modeling, we show that mildly selective self-assembled monolayers can influence the strength and configuration in which analytes interact with plasmonic surfaces, diversifying the resulting SERS fingerprints. Since each sensor generates a modulated signature, the implicit value of increasing the dimensionality of datasets is shown using cell lysates for all possible combinations of up to 9 fingerprints. Reliable improvements in mean discriminatory accuracy towards 100% are achieved with each additional surface functionality. This arrayed label-free platform illustrates the wide-ranging potential of high-dimensionality artificial-nose based sensing systems for more reliable assessment of complex biological matrices.


Asunto(s)
Técnicas Biosensibles , Nariz Electrónica , Espectrometría Raman/métodos , Fenómenos Químicos , Oro/química , Nanopartículas del Metal/química , Modelos Biológicos , Simulación de Dinámica Molecular , Análisis Multivariante , Espectrometría Raman/instrumentación
8.
Nat Commun ; 11(1): 192, 2020 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-31924791

RESUMEN

Epithelial-mesenchymal transition (EMT) is critically involved in a variety of biological processes. Electrochemical sensing offers potential to develop more effective technology for EMT detection. In this study, by using the unique performance of quantum dot (QD)-nanocomposite materials, we establish an electrochemical biosensor that can specifically detect the change of E-cadherin and analyze different stages of EMT. The signal for EMT is largely magnified due to the transmission of molecular information to the electronic device. In addition, differential pulse voltammetry reveals that the response of the electrochemical signals is rapid and sensitive, due to the synergistic effect of QDs and carbon nanotube-gold nanoparticles. Our study thus suggests that electrochemical sensing is an effective technology for detecting EMT and may have broad applications in analyzing various cell type transitions.


Asunto(s)
Técnicas Biosensibles/instrumentación , Cadherinas/aislamiento & purificación , Electroquímica/instrumentación , Electroquímica/métodos , Transición Epitelial-Mesenquimal , Células A549 , Antígenos CD/aislamiento & purificación , Electrodos , Diseño de Equipo , Oro/química , Humanos , Nanopartículas del Metal/química , Nanocompuestos/química , Nanotubos de Carbono/química , Puntos Cuánticos/química , Sensibilidad y Especificidad
9.
Anal Bioanal Chem ; 412(6): 1317-1324, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31927600

RESUMEN

Herein, a dual-emission metal-organic framework based ratiometric fluorescence nanoprobe was reported for detecting copper(II) ions. In particular, carbon dots (CDs) and gold nanoclusters (AuNCs) were embedded into ZIF-8 (one of the classical metal-organic frameworks) to form CDs/AuNCs@ZIF-8 nanocomposites, which exhibited dual-emission peaks at UV excitation. In the presence of Cu2+, the fluorescence attributed to AuNCs can be rapidly quenched, while the fluorescence of CDs serves as reference with undetectable changes. Therefore, the CDs/AuNCs@ZIF-8 nanocomposites were utilized as a ratiometric fluorescence nanoprobe for sensitive and selective detection of Cu2+. A good linear relationship between the ratiometric fluorescence signal of CDs/AuNCs@ZIF-8 and Cu2+ concentration was obtained in the range of 10-3-103 µM, and the detection limit was as low as 0.3324 nM. The current ratiometric fluorescence nanoprobe showed promising prospects in cost-effective and rapid determination of Cu2+ ions with good sensitivity and selectivity. Furthermore, this nanoprobe has been successfully applied for the quantitative detection of Cu2+ in serum samples, indicating its value of practical application. Graphical abstract Carbon dots (CDs) and gold nanoclusters (AuNCs) were embedded into metal-organic frameworks (ZIF-8) to form CDs/AuNCs@ZIF-8 nanocomposites, which exhibited dual-emission peaks at 365 nm excitation. In the presence of Cu2+, the fluorescence emission peak at 574 nm can rapidly respond by quenching, while the fluorescence at 462 nm serves as reference with undetectable changes.


Asunto(s)
Carbono/química , Cobre/análisis , Oro/química , Nanopartículas del Metal/química , Estructuras Metalorgánicas/química , Puntos Cuánticos/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Cobre/sangre , Humanos , Límite de Detección
10.
Bioelectrochemistry ; 132: 107416, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31981968

RESUMEN

A hybrid bilayer lipid membrane (hBLM), constructed with a 1-hexadecanethiol self-assembled interior leaflet and a 1,2-dipalmitoyl-sn-glycero-3-cytidine nucleolipid exterior leaflet, was deposited at the surface of a gold (111) electrode. This system was used to investigate the molecular recognition reaction between the cytosine moieties of the lipid head group with guanine molecules in the bulk electrolyte solution. Electrochemical measurements and photon polarization modulation infrared reflection absorption spectroscopy (PMIRRAS) were employed to characterize the system and determine the extent of the molecular recognition reaction. The capacitance of the hBLM-covered gold electrode was very low (~1 µF cm-2), therefore the charge density at the gold surface was small. Changing the electrode potential had a minimal effect on the complexation between the cytosine moieties and guanine molecules due to small changes in the static electric field across the membrane. This behavior favored the formation of the guanine-cytosine complex.


Asunto(s)
Citosina/química , Electrodos , Oro/química , Guanina/química , Membrana Dobles de Lípidos/química , Espectrofotometría Infrarroja
11.
Chem Commun (Camb) ; 56(12): 1784-1787, 2020 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-31950129

RESUMEN

Nanozymes have attracted extensive attention due to their great potential as alternatives to natural enzymes. Optical control as an external stimulus has become the most attractive method because of its high spatial and temporal resolution. Under the action of excitation light, free electrons on the surface of gold nanorods (GNRs) will collectively oscillate, which is called localized surface plasmon resonance (LSPR). This unique LSPR effect is promising in the application of plasmon-accelerated enzyme-like catalytic reactions. Pt-tipped gold nanorod-based nanozymes (Pt-GNRs) were synthesized by the modification of Pt nanoclusters onto the tips of GNRs. The as-prepared Pt-GNRs exhibited excellent enzyme-like catalytic activity toward hydrogen peroxide. Furthermore, it was found that the enzyme-like catalytic activity of Pt-GNRs could be notably enhanced using near-infrared (NIR) light irradiation, because of the photothermal effect and hot electron effect produced by the LSPR of GNRs. Finally, the catalytic activity and cytotoxicity of Pt-GNRs were evaluated in 4T1 cells, which further demonstrated that the Pt-GNR-based nanozymes possess great potential in cancer treatment.


Asunto(s)
Antineoplásicos/química , Oro/química , Nanopartículas del Metal/química , Platino (Metal)/química , Resonancia por Plasmón de Superficie , Antineoplásicos/farmacología , Catálisis , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Oro/farmacología , Humanos , Rayos Infrarrojos , Platino (Metal)/farmacología , Relación Estructura-Actividad
12.
Chem Commun (Camb) ; 56(14): 2135-2138, 2020 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-31970341

RESUMEN

Based on the structural programmability and spatial addressability of DNA nanodevices, a target-triggered, enzyme-free 3D DNA walker, comprising of hairpin DNA assembled gold nanoparticles with a local catalytic hairpin assembly reaction, was developed for the highly sensitive detection of intracellular tumor-associated microRNAs.


Asunto(s)
ADN/química , MicroARNs/química , Técnicas de Amplificación de Ácido Nucleico , Línea Celular Tumoral , Oro/química , Células HEK293 , Humanos , Nanopartículas del Metal/química
13.
Chem Commun (Camb) ; 56(10): 1561-1564, 2020 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-31930270

RESUMEN

A glass nanopipette functionalized with ATP-responsive gold nanoparticle assemblies was developed for ATP detection in single-cells and used for analysing the content change of ATP during electrostimulus (ES)-induced apoptosis. The variation of ATP content in single normal cells and cancer cells during apoptosis was detected by the method.


Asunto(s)
Adenosina Trifosfato/análisis , Oro/química , Nanopartículas del Metal/química , Nanotecnología/métodos , Apoptosis , Línea Celular , Electricidad , Vidrio/química , Células HeLa , Humanos , Microscopía Fluorescente , Nanoporos , Análisis de la Célula Individual
14.
Chem Commun (Camb) ; 56(11): 1717-1720, 2020 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-31942593

RESUMEN

A novel sensor array based on a (+)AuNP/AuNC nanocomposite was constructed for the selective discrimination of 10 types of Gram-negative bacteria (including 3 types of antibiotic-resistant strains) at a low concentration level of OD600 = 0.015. By recognizing the triple optical patterns of Gram-negative bacteria with the assistance of LDA, the sensor array is able to group the bacteria with respect to their species to each other.


Asunto(s)
Técnicas de Tipificación Bacteriana/métodos , Bacterias Gramnegativas/aislamiento & purificación , Nanopartículas del Metal/química , Análisis por Conglomerados , Análisis Discriminante , Oro/química , Bacterias Gramnegativas/clasificación , Bacterias Grampositivas/clasificación , Bacterias Grampositivas/aislamiento & purificación , Humanos , Nanocompuestos/química , Dispersión de Radiación , Espectrometría de Fluorescencia , Orina/microbiología , Vancomicina/química
15.
Chem Commun (Camb) ; 56(11): 1705-1708, 2020 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-31942910

RESUMEN

We report ultrathin organic photovoltaic elements optimized to run photofaradaic reactions in biological conditions. We demonstrate concurrent oxygen reduction to hydrogen peroxide and glucose oxidation. The devices are powered by deep-red irradiation in the tissue transparency window. We utilize bilayers of phthalocyanine, acting as the light absorber, and perylene diimide, functioning as both electron-acceptor and the hydrogen peroxide evolution electrocatalyst. These heterojunction bilayers are stable when irradiated in simulated physiological conditions, producing photovoltages sufficient to simultaneously drive cathodic oxygen reduction to H2O2 and anodic oxidation of glucose. We find that optimization of the anode metal is critical for sustained photofaradaic reactivity. Our results demonstrate a robust "wet" thin film photovoltaic with potential for physiological applications where localized electrochemical manipulation is desired, in particular the delivery of reactive oxygen species.


Asunto(s)
Técnicas Electroquímicas/métodos , Peróxido de Hidrógeno/síntesis química , Imidas/química , Indoles/química , Perileno/análogos & derivados , Técnicas Electroquímicas/instrumentación , Diseño de Equipo , Glucosa/química , Oro/química , Imidas/efectos de la radiación , Indoles/efectos de la radiación , Luz , Membranas Artificiales , Oxidación-Reducción , Oxígeno/química , Perileno/química , Perileno/efectos de la radiación , Fotoquímica/métodos
16.
Chemphyschem ; 21(3): 188-193, 2020 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-31912640

RESUMEN

Tip-enhanced Raman spectroscopy (TERS) is a promising technique for structural studies of biological systems and biomolecules, owing to its ability to provide a chemical fingerprint with sub-diffraction-limit spatial resolution. This application of TERS has thus far been limited, due to difficulties in generating high field enhancements while maintaining biocompatibility. The high sensitivity achievable through TERS arises from the excitation of a localized surface plasmon resonance in a noble metal atomic force microscope (AFM) tip, which in combination with a metallic surface can produce huge enhancements in the local optical field. However, metals have poor biocompatibility, potentially introducing difficulties in characterizing native structure and conformation in biomolecules, whereas biocompatible surfaces have weak optical field enhancements. Herein, a novel, biocompatible, highly enhancing surface is designed and fabricated based on few-monolayer mica flakes, mechanically exfoliated on a metal surface. These surfaces allow the formation of coupled plasmon enhancements for TERS imaging, while maintaining the biocompatibility and atomic flatness of the mica surface for high resolution AFM. The capability of these substrates for TERS is confirmed numerically and experimentally. We demonstrate up to five orders of magnitude improvement in TERS signals over conventional mica surfaces, expanding the sensitivity of TERS to a wide range of non-resonant biomolecules with weak Raman cross-sections. The increase in sensitivity obtained through this approach also enables the collection of nanoscale spectra with short integration times, improving hyperspectral mapping for these applications. These mica/metal surfaces therefore have the potential to revolutionize spectromicroscopy of complex, heterogeneous biological systems such as DNA and protein complexes.


Asunto(s)
Silicatos de Aluminio/química , Materiales Biocompatibles/química , Oro/química , Microscopía de Fuerza Atómica/instrumentación , ADN/análisis , Microscopía de Fuerza Atómica/métodos , Espectrometría Raman/métodos , Resonancia por Plasmón de Superficie/métodos
17.
J Photochem Photobiol B ; 203: 111741, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31901721

RESUMEN

Spinal cord injury (SCI) is a distressing injury and an irretrievable dramatic event that can debilitate victims for lifespan. Recovery and treatment of SCI is critical challenges for medicine, to overcome the hurdles stem cells and hydrogel scaffolds implantation is a boon for SCI recovery. In this regard, we reported the synthesis of Gold nanoparticles (Au NPs) loaded Agarose/Poly (N-isopropylacrylamide) (PNIPAM) as promising materials for SCI treatment. Herein, Au NPs was synthesized by well-established citrate reduction method and the prepared materials were characterised by UV-visible spectroscopy (UV-vis), Transmission electron microscopy (TEM), Fourier- transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), and EDAX analysis. The microscopic images showed an elliptical or ovoid porous structure nature of hydrogel, and successful and homogenous loading of photo plasmonic nanoparticles into the hydrogel structure. The in vitro cell viability and inflammation analyses data exhibited that prepared hydrogels have no toxic to the cells and displayed high anti-regenerative ability with bone marrow Mesenchymal stem cells (MSCs) and macrophages cells. The in vivo analysis study demonstrated that the treated materials with encapsulated MSCs have greater nerve tissue regeneration efficacy which was confirmed by the results of BBB scores. The hind limb locomotion of treated model animals was totally vanished after post-operational surgery. It's established that implanted nano-hydrogel materials combined with MSCs have quicker recovery of motor function after post-operative surgery, when compared to the other implanted animal groups.


Asunto(s)
Materiales Biocompatibles/química , Hidrogeles/química , Trasplante de Células Madre Mesenquimatosas , Nanopartículas del Metal/química , Traumatismos de la Médula Espinal/terapia , Vejiga Urinaria/fisiopatología , Resinas Acrílicas/química , Animales , Células de la Médula Ósea/citología , Oro/química , Miembro Posterior/fisiología , Locomoción , Células Madre Mesenquimatosas/química , Células Madre Mesenquimatosas/citología , Tejido Nervioso/fisiología , Regeneración , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/patología , Andamios del Tejido/química
19.
J Photochem Photobiol B ; 203: 111770, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31918236

RESUMEN

Dopamine (DA) is a monoamine neurotransmitter of phenethylamine and catecholamine families, which is present in the central nervous system (CNS) and its periphery. Since DA is associated with several functions in the brain and body (motivational salience, reward, motor control, paracrine messenger, etc.), any imbalance in the DA level can trigger several neurodegenerative and other diseases. On the other hand, the spherical gold nanoparticles (AuNPs) can be used for drug delivery in several parts of the body. In addition, AuNPs also have the potentiality to penetrate through the blood-brain barrier and interact with the central nervous system without causing any toxicity. In view of many applications, it is important to look into the interaction between DA and AuNPs for a potential drug delivery model in DA related diseases. Here, we have used the steady-state and time-resolved fluorescence spectroscopic tools to investigate the binding interaction of DA with AuNPs. The nature of the quenching mechanism was confirmed through both steady-state and time-resolved fluorescence measurements. The binding constants along with the number of binding sites were estimated from the steady-state fluorescence measurements. The distance between DA and AuNPs was calculated using Förster's theory to verify the possibility of fluorescence resonance energy transfer (FRET) from DA to AuNPs.


Asunto(s)
Dopamina/química , Oro/química , Nanopartículas del Metal/química , Sitios de Unión , Transferencia Resonante de Energía de Fluorescencia , Espectrometría de Fluorescencia , Termodinámica
20.
J Photochem Photobiol B ; 203: 111778, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31931389

RESUMEN

In the last decade, gold nanoparticles have emerged as promising agents for in vitro bio-sensing and in vivo cancer theranostics. However, different investigations have reported widely varying cytotoxicity and uptake efficiency of gold nanoparticles depending upon their size. Therefore, more extensive studies are needed to standardize these biological effects as a function of size on a particular cell line. In addition, to obtain robust confirmation on the correlation of a size to biological effect, thorough mechanistic study must also be performed. In this study, the size dependent biological activities of gold nanoparticles on osteosarcoma cells is investigated towards exploring their potential theranostic application in bone cancer, for which very scarce literature reports are available. Tris-assisted citrate based method was optimized to synthesize stable gold naoparticles of 40-60 nm sizes. Nanoparticles were characterized through UV-Vis spectroscopy, field emission scanning electron microscope (FESEM) and dynamic light scattering (DLS). Increasing concentrations of gold nanoparticles (AuNPs) of 46 nm size, enhanced the rate of reactive oxygen species (ROS)-induced apoptosis in MG63 cells by disrupting their mitochondrial membrane potential. Considerably higher cell death was observed for 46 and 60 nm AuNPs compared to 38 nm at all concentrations of 200, 400 and 800 ng/mL. Further, molecular signatures of cellular apoptosis under nanoparticle treatment were optically assessed through surface enhanced Raman scattering (SERS). A significant Raman enhancement in cancer cells under treatment of larger gold nanoparticles (46 and 60 nm) at fixed wavelength of 785 nm and laser power of 8.0 mW was evident. In corroboration with molecular biology techniques, SERS observation confirmed the size-dependent apoptotic phenomena in osteosarcoma cells under treatment of gold nanoparticles. Study demonstrates a facile, non-active targeting approach for detection of size-dependent AuNP-induced apoptosis in osteosarcoma cells through label-free SERS method.


Asunto(s)
Apoptosis/efectos de los fármacos , Oro/química , Nanopartículas del Metal/toxicidad , Caspasa 3/metabolismo , Línea Celular Tumoral , Dispersión Dinámica de Luz , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Nanopartículas del Metal/química , Microscopía Fluorescente , Osteosarcoma/metabolismo , Osteosarcoma/patología , Tamaño de la Partícula , Especies Reactivas de Oxígeno/metabolismo , Espectrometría Raman
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