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1.
Chemosphere ; 242: 125201, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31677514

RESUMO

Photocatalytic disinfection with high performance is thought to be a promising way for water purification. Herein, plasmonic Ag doped urea-derived graphitic carbon nitride (g-C3N4) composites were fabricated via in-situ photo-deposition at room temperature as the visible-light photocatalyst. Scan electron microscopy and transmission electron microscopy images showed the uniform dispersion of Ag nanoparticles on the surface of g-C3N4 sheet, which facilitated the synergistic effect of antibacterial performance from Ag and photocatalytic property from Ag/g-C3N4 composites. Photocatalytic water disinfection against Escherichia coli with visible light was performed to demonstrate the improved photocatalytic property with assistance of Ag. The 3-Ag/g-C3N4 exhibited the best bactericidal performance by inactivating all bacteria within 120 min with damaged cell membranes of Escherichia coli observed by scan electron microscopy and transmission electron microscopy images. Photoluminescence spectra, steady-state surface photovoltage spectra, photocurrent response, and electrochemical impedance spectra results revealed that Ag nanoparticles inhibited the recombination of photo-generated e- and h+ pairs and further reinforced the photocatalytic performance of g-C3N4. Scavenger experiments indicated that h+ produced on valence band of g-C3N4 dominated the photocatalytic disinfection process against Escherichia coli. This work further proved Ag/g-C3N4 showed great potential in photocatalytic water disinfection under visible-light irradiation.

2.
Nanoscale ; 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31720650

RESUMO

Lanthanide-doped nanoparticles have long been stereotyped for optical luminescence bioimaging. However, they are known to be unable to produce therapeutic abilities. Here, we describe a lanthanide-based theranostic agent, namely, prussian blue (PB)-coated NaErF4@NaYF4@NaNdF4 core/shell/shell nanocrystals encapsulated in a phospholipid PEG micelle (PEG-CSS@PB), which showed switched imaging and hyperthermia abilities under distinct near infrared (NIR) light activation. The erbium (Er3+)-enriched inner core nanocrystals (NaErF4) enabled the emission of tissue-penetrating luminescence (1525 nm) in the second biological window (NIR-II, 1000-1700 nm), which endowed high-resolution optical imaging of the blood vessels and tumors under ∼980 nm excitation. High neodymium (Nd3+) concentrations in the epitaxial outer NaNdF4 shell introduced maximum cross relaxation processes that converted the absorbed NIR light (∼808 nm) into heat at high efficiencies, thus providing abilities for photothermal therapy (PTT). Importantly, the coated Prussian blue (PB) increased light absorption by about 10-fold compared to the composite free of PB, thus entailing a high light-to-heat conversion efficiency of ∼50.5%. This commensurated with that of well-established gold nanorods. As a result, the PEG-CSS@PB nanoparticles with MTT-determined low toxicities resulted in ∼80% death of HeLa cells at a dose of 600 µg mL-1 under 808 nm laser irradiance (1 W cm-2) for 10 min. Moreover, utilizing the same light dose, a single PTT treatment in tumor-bearing BALB/c mice shrunk the tumor size by ∼12-fold compared to the tumors without treatment. Our results, here, constituted a solid step forward to entitle lanthanide-based nanoparticles as theranostic agents in nanomedicine studies.

3.
Mater Sci Eng C Mater Biol Appl ; 105: 110088, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546431

RESUMO

The antibacterial PE cling films were successfully obtained through precipitation polymerization and UV polymerization of N,N'-[(4,5-dihydroxy-1, 2-phenylene)bis(methylene)] bisacrylamide (OHABA) monomers, respectively. The inhibition rates of the PE cling films using UV polymerization method against E. coli and B. subtilis were 85.1% and 92.1% respectively, whilst the inhibition rates of the antibacterial PE cling films prepared by precipitation polymerization method against E. coli and B. subtilis were 97.7% and 91.4% respectively. The antibacterial PE cling films using precipitation polymerization method was found to have more excellent antibacterial ability than that using UV polymerization method probably due to the larger surface coverage of OHABA. The POHABA modified PE cling films have great potential in food packaging.

4.
Biophys Chem ; 253: 106217, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31306917

RESUMO

The production of giant unilamellar vesicles (GUVs) with specific size and structure has been a challenge on the design of quantitative biological assays in cell-mimetic micro-compartments. In this study, the effect of electroformation parameters (electric potential, frequency, and temperature) on the size of GUVs was investigated. Using response surface methodology based on Box-Behnken design, GUVs from neutral, positive and negative charges were formulated. The average diameter of GUVs was determined for each formulation. The acquired data of these GUVs were successfully fitted with quadratic regression models. These models were applied to visualize the parameters for ideal GUVs with wanted diameters by the obtained phase diagrams. These results show that response surface methodology can be used to estimate the electroformation parameters for specifically sized GUVs.

5.
Phys Rev E ; 99(6-1): 063002, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31330730

RESUMO

We use an ultrasonic standing wave to simultaneously trap and deform thousands of soft lipid vesicles immersed in a liquid solution. In our device, acoustic radiation stresses comparable in magnitude to those generated in optical stretching devices are achieved over a spatial extent of more than ten acoustic wavelengths. We solve the acoustic scattering problem in the long-wavelength limit to obtain the radiation stress. The result is then combined with thin-shell elasticity theory to form expressions that relate the deformed geometry to the applied acoustic field intensity. Using observation of the deformed geometry and this model, we rapidly extract mechanical properties, such as the membrane Young's modulus, from populations of lipid vesicles.

6.
Anal Chem ; 91(10): 6859-6864, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31020837

RESUMO

The chemical signal communication among organelles in the cell is extremely important for life. We demonstrate here the chemical signal communication between two protoorganelles using cascade enzyme reactions in a lipid-based artificial cell. Two protoorganelles inside the artificial cell are large unilamellar vesicles containing glucose oxidase (GOx-LUVs) and a vesicle containing horseradish peroxidase (HRP) and Amplex red, respectively. The glucose molecules outside the artificial cell penetrate the lipid bilayer through mellitin pores and enter into one protoroganelle (GOx-LUV) to produce H2O2, which subsequently is transported to the other protoorganelle to oxidize Amplex red into red resorufin catalyzed by HRP. The number of GOx-LUVs in an artificial cell is controlled by using a GOx-LUV solution with different density during the electroformation. The reaction rate for resorufin in the protoorganelle increases with more GOx-LUVs inside the artificial cell. The artificial cell developed here paves the way for a more complicated signal transduction mechanism study in a eukaryocyte.

7.
Biomater Sci ; 7(5): 2165-2173, 2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-30896681

RESUMO

Neurodegenerative diseases and acute nerve injuries are becoming global clinical problems. Engineering three-dimensional (3D), anisotropic neural cellular structures in vitro is therefore desirable in the regenerative medicine research community. Here, we present, for the first time, a single-step, facile but delicate, fabrication of a 3D macroporous microfibrous scaffold with both anisotropic nanogrooved topography and in situ functionalization with a mussel inspired bioadhesive, poly(norepinephrine) (pNE). Specifically, immiscible blends of polycaprolactone (PCL) and polyethylene oxide (PEO) were electrospun into a grounded coagulation bath containing the precursor of pNE. Upon jet entrance in the bath, both phase-separation-driven longitudinal nanotopography and in situ pNE surface functionalization were introduced on individual microfibers that were packed into a 3D macroporous structure. The resulting scaffold significantly promoted 3D neurite extension capacity, 8-fold higher neurite extension over the isotropic counterpart, demonstrating that such a scaffold has great promise in 3D neural cell culture for nerve tissue modelling and engineering.


Assuntos
Materiais Biocompatíveis/farmacologia , Nanotecnologia , Neuritos/efeitos dos fármacos , Neuritos/metabolismo , Adesividade , Animais , Anisotropia , Materiais Biocompatíveis/química , Eletricidade , Teste de Materiais , Células PC12 , Poliésteres/química , Polietilenoglicóis/química , Porosidade , Ratos
8.
ACS Nano ; 13(3): 3573-3579, 2019 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-30855945

RESUMO

Topological defects are crucial to the shaping of the crystalline membrane systems such as lipid bilayers, virus capsids, and graphene as well as the arrangement of cells in tissues. In a typical case, the introduction of disclination defects elastically buckles the crystalline membranes into conical shapes. However, how planar membranes transform to cones triggered by disclinations is still rarely observed in the experiments. Herein, we experimentally observe the transformation from phospholipid bicelles to cones in response to disclinations. During the transformation process, the wall thickness increases, while the conical generatrix length remains the same with respect to the radius of bicelles. The cones with apex angles of 112.8°, 83.6°, 60°, 39°, and 19.2° are observed when 1, 2, 3, 4, and 5 pentagon defects are introduced, respectively. Monodispersed microcones are obtained by adjusting aging temperature and time. These microcones are then used as templates to form platinum conical micromotors with open tips or closed tips, which display different heading directions in H2O2 solution. Our work provides a shape evolution pathway of planar membranes in response to disclinations. The homogeneous microcones can find wide applications in micromotors fabrication, the study of curvature-dependent processes, and the formation of advanced materials.

9.
Nanoscale ; 11(4): 1968-1977, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30644942

RESUMO

Of the many strategies for precise tumor treatment, near-infrared (NIR) light-activated "one-for-all" theranostic modality with real-time diagnosis and therapy has attracted extensive attention from researchers. Herein, a brand-new theranostic nanoplatform was established on versatile vanadium nitride (VN) nanosheets, which show significant NIR optical absorption, and resultant photothermal effect and reactive oxygen species activity under NIR excitation, thereby realizing the synergistic action of photothermal/photodynamic co-therapy. As expected, systematic in vitro and in vivo antitumor evaluations demonstrated efficient cancer cell killing and solid tumor removal without recurrence. Meanwhile, the surface modification of VN nanosheets with poly(allylamine hydrochloride) and bovine serum albumin enhanced the biocompatibility of VN and made it more suitable for in vivo delivery. Moreover, VN has been ascertained as a potential photoacoustic imaging contrast for in vivo tumor depiction. Thus, this work highlights the potential of VN nanosheets as a single-component theranostic nanoplatform.


Assuntos
Nanoestruturas/química , Fármacos Fotossensibilizantes/química , Vanádio/química , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/uso terapêutico , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Células Hep G2 , Humanos , Hipertermia Induzida , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Poliaminas/química , Espécies Reativas de Oxigênio/metabolismo , Soroalbumina Bovina/química , Nanomedicina Teranóstica
11.
Anal Chem ; 2018 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-30481002

RESUMO

Giant unilamellar vesicles (GUVs) are widely used as artificial cell models which contribute to elucidate fundamental questions on origin of life and cell functions. Herein, the GUV microarrays were developed using a point-to-plane electrode system combined with microcontact stripping technique. The biomolecules (DNA, etc.) were selectively encapsulated only inside patterned GUVs. The GUV arrays were used to investigate species mass transport across cell membranes. The release of carboxyfluorescein from GUVs showed a melittin concentration dependent manner. The diffusion coefficient were 0.37 × 10-11, 0.36 × 10-11, 0.54 × 10-11, 1.10 × 10-11, 1.74 × 10-11, 2.31 × 10-11, and 3.62 × 10-11 m2/s for 0, 0.5, 1.0, 2.0, 3.0, 4.0, and 5.0 µM melittin, respectively. The GUV arrays were also a good platform for cell metabolism investigation. Horseradish peroxidase (HRP) loaded GUV microarrays were used to mimic internal metabolism by exposing them to the substrates of H2O2 and o-PD to yield fluorescent 2,3-diaminophenazine (2,3-DAP).The proposed GUV arrays have great potential in cell function studies.

12.
iScience ; 8: 138-147, 2018 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-30312864

RESUMO

Nature has evolved elaborate, dynamic organelle morphologies for optimal organelle functions. Among them, cisternae stacks are the universal structure for most organelles. However, compared with the well-studied spherical cell/organelle membrane mimic, the fabrication of the ubiquitously present cisternal organelle-like membrane structures for organelle mimic remains a challenging task. Herein, rough endoplasmic reticulum (RER)-like helicoidal cisternae stacks were assembled to mimic the enzyme crowded environment in spatially confined RER cisternae. RER-like single helicoid, multiple helicoids, and secondary helix are all observed. Membrane electrostatics drives their formation and controls the percentages, which indicates the possible role of membrane electrostatics in RER shaping. The organelle-like cisternae stacks can reversibly expand and compress, which provides modulated crowded or de-crowded enzyme environment for biochemical reactions. This work provides advanced membrane models, and novel mechanisms for organelle shaping and helicoids formation, and holds great potential in biomimetics, cell biology, and advanced materials design.

13.
J Environ Sci (China) ; 73: 47-57, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30290871

RESUMO

Dyestuffs and heavy metal ions in water are seriously harmful to the ecological environment and human health. Three-dimensional (3D) flowerlike Fe(OH)3 microspheres were synthesized through a green yet low-cost injection method, for the removal of organic dyes and heavy metal ions. The Fe(OH)3 microspheres were characterized by thermal gravimetric analysis (TGA), Fourier transform infrared (FT-IR), and transmission electron microscopy (TEM) techniques. The adsorption kinetics of Congo Red (CR) on Fe(OH)3 microspheres obeyed the pseudo-second-order model. Cr6+ and Pb2+ adsorption behaviors on Fe(OH)3 microspheres followed the Langmuir isotherm model. The maximum adsorption capacities of the synthesized Fe(OH)3 were 308, 52.94, and 75.64mg/g for CR, Cr6+, and Pb2+ respectively. The enhanced adsorption performance originated from its surface properties and large specific surface area of 250m2/g. The microspheres also have excellent adsorption stability and recyclability. Another merit of the Fe(OH)3 material is that it also acts as a Fenton-like catalyst. These twin functionalities (both as adsorbent and Fenton-like catalyst) give the synthesized Fe(OH)3 microspheres great potential in the field of water treatment.


Assuntos
Compostos Férricos/química , Metais Pesados/química , Microesferas , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Biomacromolecules ; 19(11): 4379-4385, 2018 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-30231209

RESUMO

Multicompartmentalized microreactors are considered as cell mimics with hierarchical structures inspired by mammalian cells. We report the successful assembly and encapsulation of purified nuclei from RAW 264.7 cells (pNuc) into alginate-based microreactors. We demonstrate the preserved function of nuclei within the microreactors for mRNA production. Further, we load catalase-loaded liposomes (Lcat) into the microreactors to break down hydrogen peroxide (H2O2) into oxygen and water. Assemblies containing both natural pNuc and synthetic Lcat show significantly higher mRNA production in the presence of H2O2 compared to microreactors without Lcat or no H2O2 present, suggesting a beneficial effect of the locally enzymatically produced oxygen for transcription. This novel type of microreactors, containing both natural and synthetic compartments, presents a substantial advancement from assemblies equipped with solely synthetic units and offers opportunities as hypoxia models or for cell-free protein synthesis.

15.
Colloids Surf B Biointerfaces ; 172: 459-463, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30196231

RESUMO

Biological membrane plays an important role in maintaining an osmotic equilibrium between the cytoplasm and the extracellular solution of cells. Here, the giant unilamellar vesicles (GUVs) as cell models were used to investigate the effect of osmotic stress on phospholipid membranes. The deformation of GUVs, including inward budding and outward budding, was systematically investigated by the osmotic press from glucose, sucrose, LiCl, and KCl solutions. The permeability (P) of DMPC, DMPC/10 mol% Chol GUVs, DMPC/25 mol% Chol GUVs, and DMPC/40 mol% Chol GUVs in glucose, sucrose, LiCl, and KCl solutions were all obtained. The P value decreases with the addition of more cholesterol in the bilayer. The monovalent cations caused higher permeability of lipid bilayer membranes due to their combination with phospholipids. The molar flux of water (J) value was found to be the key factor for determining the deformation state from mainly inward budding to mainly outward budding. The findings in this paper may help us to understand cell transformation triggered with osmotic stress.

16.
Langmuir ; 34(32): 9561-9571, 2018 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-30028144

RESUMO

The nanoscale organization and dynamics of lipid molecules in self-assembled membranes is central to the biological function of cells and in the technological development of synthetic lipid structures as well as in devices such as biosensors. Here, we explore the nanoscale molecular arrangement and dynamics of lipids assembled in monolayers at the surface of highly ordered pyrolytic graphite (HOPG), in different ionic solutions, and under electrical potentials. Using a combination of atomic force microscopy and fluorescence recovery after photobleaching, we show that HOPG is able to support fully formed and fluid lipid membranes, but mesoscale order and corrugations can be observed depending on the type of the lipid considered (1,2-dioleoyl- sn-glycero-3-phosphocholine, 1,2-dioleoyl- sn-glycero-3-phospho-l-serine (DOPS), and 1,2-dioleoyl-3-trimethylammoniumpropane) and the ion present (Na+, Ca2+, Cl-). Interfacial solvation forces and ion-specific effects dominate over the electrostatic changes induced by moderate electric fields (±1.0 V vs Ag/AgCl reference electrode) with particularly marked effects in the presence of calcium, and for DOPS. Our results provide insights into the interplay between the molecular, ionic, and electrostatic interactions and the formation of dynamical ordered structures in fluid lipid membranes.

17.
Langmuir ; 34(23): 6874-6886, 2018 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-29776311

RESUMO

The success of nanoparticulate formulations in drug delivery depends on various aspects including their toxicity, internalization, and intracellular location. Vesicular assemblies consisting of phospholipids and amphiphilic block copolymers are an emerging platform, which combines the benefits from liposomes and polymersomes while overcoming their challenges. We report the synthesis of poly(cholesteryl methacrylate)- block-poly(2-(dimethylamino) ethyl methacrylate) (pCMA- b-pDMAEMA) block copolymers and their assembly with phospholipids into hybrid vesicles. Their geometry, their ζ-potential, and their ability to adsorb onto polymer-coated surfaces were assessed. Giant unilamellar vesicles were employed to confirm the presence of both the phospholipids and the block copolymer in the same membrane. Furthermore, the cytotoxicity of selected hybrid vesicles was determined in RAW 264.7 mouse macrophages, primary rat Kupffer cells, and human macrophages. The internalization and lysosomal escape ability of the hybrid vesicles were confirmed using RAW 264.7 mouse macrophages. Taken together, our findings illustrate that the reported hybrid vesicles are a promising complementary drug delivery platform for existing liposomes and polymersomes.

18.
Environ Sci Pollut Res Int ; 25(20): 19480-19487, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29730757

RESUMO

Disinfection of bacteria in water with sustainable and energy-efficient methods is still a great challenge. Herein, a novel gelatin sponge with embedded AgNPs is fabricated via freeze-drying using gelatin as the reducing agent to synthesize AgNPs in situ. UV-vis spectroscopy, HRTEM, XRD, and XPS characterization prove the formation of AgNPs with an average size of 8.55 ± 0.35 nm. TEM and SEM images confirm the even distribution of AgNPs throughout the AgNPs/gelatin sponges. The composite sponge has a low bulk density of 20 ± 3.5 mg/cm3 and a pore size of 6.2 ± 1.5 µm. The AgNPs/gelatin sponges exhibit excellent antibacterial performance to E. coli in water, probably by destroying their cell membranes. The porous AgNPs/gelatin composite sponges are promising filter materials for water disinfection. The removal rate of AgNPs/gelatin composite sponges on E. coli reached almost 100%. Graphical abstract ᅟ.

19.
Adv Mater ; 30(25): e1707482, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29707837

RESUMO

Membranes in cells display elaborate, dynamic morphologies intimately tied to defined cellular functions. Cisternae stacks are a common membrane morphology in cells widely found in organelles. However, compared with the well-studied spherical cell membrane mimics, cisternae stacks as organelle membrane mimics are greatly neglected because of the difficulty of fabricating this unique structure. Herein, the grana-like cisternae stacks are assembled via the reorganization of stacked microsized bicelles to mimic grana functions. The cisternae stacks are connected by fusion regions between adjacent cisternae. The number of cisternae can be controlled from ≈4 to 15 by the variation of ethanol volume percentage. Under the stimulation of solvent or negatively charged nanoparticles, the cisternae stacks can reversibly compress and expand, similar to the "breathing" property of natural grana. During the "breathing" process, nanoparticles are reversibly captured and released. Frequency resonance energy transfer is realized on the cisternae stacks trapped with two kinds of quantum dots. The cisternae stacks provide advanced membrane model for cell biotechnology, and clues for the shaping of organelles composed of cisternae. The ability of the cisternae stacks to capture materials enables them to possibly be applied in biomimetics and the design of advanced functional materials.

20.
ACS Synth Biol ; 7(3): 945-951, 2018 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-29439569

RESUMO

The fabrication of artificial cells containing nature components is challenging. Herein we construct a thylakoid containing artificial cell (TA-cell) by forming multicompartmental structure inside giant unilamellar vesicles (GUVs) using osmotic stress. The thylakoids are selectively loaded inside each compartment in GUVs to mimic "chloroplast". The TA-cells are able to carry out photosynthesis upon light on. The TA-cells keep their 50% functionality of electron transfer for 12 days, which is twice of those of free thylakoids. Using TA-cells the inhibition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and heavy metal ions (Hg2+, Cu2+, Cd2+, Pb2+ and Zn2+) on the electron transfer process in TA-cells is systematically investigated. Their half maximal inhibitory concentration (IC50) values are 36.23 ± 1.87, 0.02 ± 0.01, 0.42 ± 0.08, 0.82 ± 0.12, 1.97 ± 0.21, and 4.08 ± 0.18 µM, respectively. Hg2+ is the most toxic ion for the photosynthesis process among these five heavy metal ions. This biomimetic system can be expanded to study other processes during the photosynthesis. The TA-cells pave a way to fabricate more complicated nature component containing artificial cells.


Assuntos
Células Artificiais/metabolismo , Células Artificiais/efeitos da radiação , Elétrons , Luz , Fotossíntese/efeitos da radiação , Tilacoides/metabolismo , Células Artificiais/efeitos dos fármacos , Diurona/farmacologia , Transporte de Elétrons/efeitos dos fármacos , Transporte de Elétrons/efeitos da radiação , Íons , Metais Pesados/química , Nanoporos , Fotossíntese/efeitos dos fármacos , Spinacia oleracea/metabolismo , Spinacia oleracea/efeitos da radiação , Tilacoides/efeitos dos fármacos , Tilacoides/efeitos da radiação
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