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1.
Nat Commun ; 11(1): 4502, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32908136

RESUMO

Biological tissues, such as muscle, can increase their mechanical strength after swelling due to the existence of many biological membrane barriers that can regulate the transmembrane transport of water molecules and ions. Oppositely, typical synthetic materials show a swelling-weakening behavior, which always suffers from a sharp decline in mechanical strength after swelling, because of the dilution of the network. Here, we describe a swelling-strengthening phenomenon of polymer materials achieved by a bioinspired strategy. Liposomal membrane nanobarriers are covalently embedded in a crosslinked network to regulate transmembrane transport. After swelling, the stretched network deforms the liposomes and subsequently initiates the transmembrane diffusion of the encapsulated molecules that can trigger the formation of a new network from the preloaded precursor. Thanks to the tough nature of the double-network structure, the swelling-strengthening phenomenon is achieved to polymer hydrogels successfully. Swelling-triggered self-strengthening enables the development of various dynamic materials.


Assuntos
Materiais Biomiméticos/química , Hidrogéis/química , Lipossomos/química , Nanoestruturas/química , Força Compressiva , Reagentes para Ligações Cruzadas/química , Lipossomos/ultraestrutura , Teste de Materiais , Microscopia Eletrônica de Transmissão , Nanoestruturas/ultraestrutura , Resistência à Tração
2.
Biosens Bioelectron ; 169: 112578, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32911317

RESUMO

The ongoing global pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to active research in its associated diagnostics and medical treatments. While quantitative reverse transcription polymerase chain reaction (qRT-PCR) is the most reliable method to detect viral genes of SARS-CoV-2, serological tests for specific antiviral antibodies are also important as they identify false negative qRT-PCR responses, track how effectively the patient's immune system is fighting the infection, and are potentially helpful for plasma transfusion therapies. In this work, based on the principle of localized surface plasmon resonance (LSPR), we develop an opto-microfluidic sensing platform with gold nanospikes, fabricated by electrodeposition, to detect the presence and amount of antibodies specific to the SARS-CoV-2 spike protein in 1µL of human plasma diluted in 1mL of buffer solution, within ∼30min. The target antibody concentration can be correlated with the LSPR wavelength peak shift of gold nanospikes caused by the local refractive index change due to the antigen-antibody binding. This label-free microfluidic platform achieves a limit of detection of ∼0.08ng/mL (∼0.5pM), falling under the clinical relevant concentration range. We demonstrate that our opto-microfluidic platform offers a promising point-of-care testing tool to complement standard serological assays and make SARS-CoV-2 quantitative diagnostics easier, cheaper, and faster.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Infecções por Coronavirus/sangue , Nanoestruturas/química , Pneumonia Viral/sangue , Glicoproteína da Espícula de Coronavírus/imunologia , Ressonância de Plasmônio de Superfície/instrumentação , Anticorpos Antivirais/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Desenho de Equipamento , Ouro/química , Humanos , Dispositivos Lab-On-A-Chip , Limite de Detecção , Nanoestruturas/ultraestrutura , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/virologia
3.
Int J Nanomedicine ; 15: 4763-4778, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32753865

RESUMO

Introduction: Methotrexate exhibits poor cutaneous bioavailability and systemic side effects on topical administration, so there is an unmet need for a novel carrier and its optimized therapy. Methotrexate-loaded nanostructured lipid carriers (MTXNLCs) were formulated and characterized to determine in vitro drug release and evaluate the role of MTXNLC gel in the topical treatment of psoriasis. Methods: A solvent diffusion technique was employed to prepare MTXNLCs, which was optimized using 32 full factorial designs. The mean diameter and surface morphology of MTXNLCs was evaluated. The crystallinity of lyophilized MTXNLCs was characterized by differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD). MTXNLCs were integrated in 1% w/w Carbopol 934 P gel base, and in vitro skin deposition studies in human cadaver skin (HCS) were carried out. Results: The optimized MTXNLCs were rod-shaped, with an average particle size of 253 ± 8.65 nm, a zeta potential of -26.4±0.86 mV, and EE of 54.00±1.49%. DSC and XRD data confirmed the formation of NLCs. Significantly higher deposition of MTX was found in HCS from MTXNLC gel (71.52 ±1.13%) as compared to MTX plain gel (38.48±0.96%). In vivo studies demonstrated significant improvement in therapeutic response and reduction in local side effects with MTXNLCs-loaded gel in the topical treatment of psoriasis. Anti-psoriatic efficacy of MTXNLCs 100 ug/cm2 compared with plain MTX gel was evaluated using imiquimod (IMQ)-induced psoriasis in BALB/c mice. The topical application of MTXNLCs to the mouse ear resulted in a significant reduction of psoriatic area and severity index, oxidative stress, inflammatory cytokines like TNF-α, IL-1ß, and IL-6 and IMQ-induced histopathological alterations in mouse ear samples. Conclusion: Developed formulation of MTXNLC gel demonstrated better anti-psoriatic activity and also displayed prolonged and sustained release effect, which shows that it can be a promising alternative to existing MTX formulation for the treatment of psoriasis.


Assuntos
Composição de Medicamentos , Géis/química , Imiquimode/uso terapêutico , Inflamação/tratamento farmacológico , Lipídeos/química , Metotrexato/uso terapêutico , Nanoestruturas/química , Psoríase/tratamento farmacológico , Administração Cutânea , Administração Tópica , Animais , Catalase/metabolismo , Citocinas/metabolismo , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Glutationa/metabolismo , Humanos , Inflamação/patologia , Malondialdeído/metabolismo , Camundongos Endogâmicos BALB C , Nanoestruturas/ultraestrutura , Tamanho do Órgão , Superóxido Dismutase/metabolismo
4.
PLoS One ; 15(7): e0228607, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645009

RESUMO

Among the first steps in inflammation is the conversion of arachidonic acid (AA) stored in the cell membranes into leukotrienes. This occurs mainly in leukocytes and depends on the interaction of two proteins: 5-lipoxygenase (5LO), stored away from the nuclear membranes until use and 5-lipoxygenase activating protein (FLAP), a transmembrane, homotrimeric protein, constitutively present in nuclear membrane. We could earlier visualize the binding of 5LO to nanodiscs in the presence of Ca2+-ions by the use of transmission electron microscopy (TEM) on samples negatively stained by sodium phosphotungstate. In the absence of Ca2+-ions 5LO did not bind to the membrane. In the present communication, FLAP reconstituted in the nanodiscs which could be purified if the His-tag was located on the FLAP C-terminus but not the N-terminus. Our aim was to find out if 1) 5LO would bind in a Ca2+-dependent manner also when FLAP is present? 2) Would the substrate (AA) have effects on 5LO binding to FLAP-nanodiscs? TEM was used to assess the complex formation between 5LO and FLAP-nanodiscs along with, sucrose gradient purification, gel-electrophoresis and mass spectrometry. It was found that presence of AA by itself induces complex formation in the absence of added calcium. This finding corroborates that AA is necessary for the complex formation and that a Ca2+-flush is mainly needed for the recruitment of 5LO to the membrane. Our results also showed that the addition of Ca2+-ions promoted binding of 5LO on the FLAP-nanodiscs as was also the case for nanodiscs without FLAP incorporated. In the absence of added substances no 5LO-FLAP complex was formed. Another finding is that the formation of a 5LO-FLAP complex appears to induce fragmentation of 5LO in vitro.


Assuntos
Proteínas Ativadoras de 5-Lipoxigenase/metabolismo , Araquidonato 5-Lipoxigenase/metabolismo , Ácido Araquidônico/metabolismo , Cálcio/metabolismo , Proteínas Ativadoras de 5-Lipoxigenase/química , Ácido Araquidônico/química , Centrifugação com Gradiente de Concentração , Eletroforese em Gel de Poliacrilamida , Humanos , Espectrometria de Massas , Microscopia Eletrônica de Transmissão , Modelos Moleculares , Nanoestruturas/ultraestrutura , Ligação Proteica , Conformação Proteica , Sacarose
5.
J Vis Exp ; (159)2020 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-32478740

RESUMO

Resistive switching crossbar architecture is highly desired in the field of digital memories due to low cost and high-density benefits. Different materials show variability in resistive switching properties due to the intrinsic nature of the material used, leading to discrepancies in the field because of underlying operation mechanisms. This highlights a need for a reliable technique to understand mechanisms using nanostructural observations. This protocol explains a detailed process and methodology of in situ nanostructural analysis as a result of electrical biasing using transmission electron microscopy (TEM). It provides visual and reliable evidence of underlying nanostructural changes in real time memory operations. Also included is the methodology of fabrication and electrical characterizations for asymmetric crossbar structures incorporating amorphous vanadium oxide. The protocol explained here for vanadium oxide films can be easily extended to any other materials in a metal-dielectric-metal sandwiched structure. Resistive switching crossbars are predicted to serve the programmable logic and neuromorphic circuits for next-generation memory devices, given the understanding of the operation mechanisms. This protocol reveals the switching mechanism in a reliable, timely, and cost-effective way in any type of resistive switching materials, and thereby predicts the device's applicability.


Assuntos
Microscopia Eletrônica de Transmissão , Óxidos/química , Metais/química , Nanoestruturas/ultraestrutura
6.
Artigo em Inglês | MEDLINE | ID: mdl-32515974

RESUMO

Geometry-matching has been known to benefit the formation of stable biological interactions in natural systems. Herein, we report that the spiky nanostructures with matched topography to the influenza A virus (IAV) virions could be used to design next-generation advanced virus inhibitors. We demonstrated that nanostructures with spikes between 5 and 10 nm bind significantly better to virions than smooth nanoparticles, due to the short spikes inserting into the gaps of glycoproteins of the IAV virion. Furthermore, an erythrocyte membrane (EM) was coated to target the IAV, and the obtained EM-coated nanostructures could efficiently prevent IAV virion binding to the cells and inhibit subsequent infection. In a postinfection study, the EM-coated nanostructures reduced >99.9% virus replication at the cellular nontoxic dosage. We predict that such a combination of geometry-matching topography and cellular membrane coating will also push forward the development of nanoinhibitors for other virus strains, including SARS-CoV-2.


Assuntos
Betacoronavirus/ultraestrutura , Infecções por Coronavirus/virologia , Nanoestruturas/ultraestrutura , Pneumonia Viral/virologia , Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Sítios de Ligação , Infecções por Coronavirus/tratamento farmacológico , Desenho de Fármacos , Humanos , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza A/ultraestrutura , Microscopia Eletrônica , Modelos Biológicos , Nanotecnologia , Pandemias , Pneumonia Viral/tratamento farmacológico , Glicoproteína da Espícula de Coronavírus/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/ultraestrutura , Internalização do Vírus/efeitos dos fármacos
7.
Artigo em Inglês | MEDLINE | ID: mdl-32551679

RESUMO

We report cellular nanosponges as an effective medical countermeasure to the SARS-CoV-2 virus. Two types of cellular nanosponges are made of the plasma membranes derived from human lung epithelial type II cells or human macrophages. These nanosponges display the same protein receptors, both identified and unidentified, required by SARS-CoV-2 for cellular entry. It is shown that, following incubation with the nanosponges, SARS-CoV-2 is neutralized and unable to infect cells. Crucially, the nanosponge platform is agnostic to viral mutations and potentially viral species, as well. As long as the target of the virus remains the identified host cell, the nanosponges will be able to neutralize the virus.


Assuntos
Betacoronavirus , Infecções por Coronavirus/prevenção & controle , Nanoestruturas , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Betacoronavirus/patogenicidade , Betacoronavirus/fisiologia , Membrana Celular/virologia , Infecções por Coronavirus/virologia , Células Epiteliais/virologia , Interações entre Hospedeiro e Microrganismos , Humanos , Pulmão/citologia , Pulmão/virologia , Macrófagos/virologia , Nanoestruturas/ultraestrutura , Nanotecnologia , Pneumonia Viral/virologia , Receptores Virais/fisiologia , Internalização do Vírus
8.
Nat Commun ; 11(1): 3188, 2020 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-32581225

RESUMO

Nitric oxide (NO) has been implicated in a variety of physiological and pathological processes. Monitoring cellular levels of NO requires a sensor to feature adequate sensitivity, transient recording ability and biocompatibility. Herein we report a single-atom catalysts (SACs)-based electrochemical sensor for the detection of NO in live cellular environment. The system employs nickel single atoms anchored on N-doped hollow carbon spheres (Ni SACs/N-C) that act as an excellent catalyst for electrochemical oxidation of NO. Notably, Ni SACs/N-C shows superior electrocatalytic performance to the commonly used Ni based nanomaterials, attributing from the greatly reduced Gibbs free energy that are required for Ni SACs/N-C in activating NO oxidation. Moreover, Ni SACs-based flexible and stretchable sensor shows high biocompatibility and low nanomolar sensitivity, enabling the real-time monitoring of NO release from cells upon drug and stretch stimulation. Our results demonstrate a promising means of using SACs for electrochemical sensing applications.


Assuntos
Técnicas Biossensoriais/métodos , Níquel/química , Óxido Nítrico/análise , Nitrogênio/química , Técnicas Biossensoriais/instrumentação , Carbono/química , Catálise , Eletroquímica , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Óxido Nítrico/metabolismo , Oxirredução
9.
Proc Natl Acad Sci U S A ; 117(26): 14667-14675, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32532923

RESUMO

Many natural materials possess built-in structural variation, endowing them with superior performance. However, it is challenging to realize programmable structural variation in self-assembled synthetic materials since self-assembly processes usually generate uniform and ordered structures. Here, we report the formation of asymmetric microribbons composed of directionally self-assembled two-dimensional nanoflakes in a polymeric matrix during three-dimensional direct-ink printing. The printed ribbons with embedded structural variations show site-specific variance in their mechanical properties. Remarkably, the ribbons can spontaneously transform into ultrastretchable springs with controllable helical architecture upon stimulation. Such springs also exhibit superior nanoscale transport behavior as nanofluidic ionic conductors under even ultralarge tensile strains (>1,000%). Furthermore, to show possible real-world uses of such materials, we demonstrate in vivo neural recording and stimulation using such springs in a bullfrog animal model. Thus, such springs can be used as neural electrodes compatible with soft and dynamic biological tissues.


Assuntos
Neuroestimuladores Implantáveis , Microtecnologia/instrumentação , Nanoestruturas , Impressão Tridimensional , Animais , Anuros , Elasticidade , Grafite/química , Íons/química , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Neurofisiologia/instrumentação , Nervo Isquiático/fisiologia
10.
Nat Commun ; 11(1): 2778, 2020 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-32513979

RESUMO

The use of photothermal agents (PTAs) in cancer photothermal therapy (PTT) has shown promising results in clinical studies. The rapid degradation of PTAs may address safety concerns but usually limits the photothermal stability required for efficacious treatment. Conversely, PTAs with high photothermal stability usually degrade slowly. The solutions that address the balance between the high photothermal stability and rapid degradation of PTAs are rare. Here, we report that the inherent Cu2+-capturing ability of black phosphorus (BP) can accelerate the degradation of BP, while also enhancing photothermal stability. The incorporation of Cu2+ into BP@Cu nanostructures further enables chemodynamic therapy (CDT)-enhanced PTT. Moreover, by employing 64Cu2+, positron emission tomography (PET) imaging can be achieved for in vivo real-time and quantitative tracking. Therefore, our study not only introduces an "ideal" PTA that bypasses the limitations of PTAs, but also provides the proof-of-concept application of BP-based materials in PET-guided, CDT-enhanced combination cancer therapy.


Assuntos
Cobre/química , Hipertermia Induzida , Neoplasias/terapia , Fósforo/química , Fototerapia , Tomografia por Emissão de Pósitrons , Animais , Morte Celular , Linhagem Celular Tumoral , Terapia Combinada , Cobre/farmacocinética , Humanos , Íons , Camundongos , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Oligopeptídeos/química , Fósforo/farmacocinética , Polietilenoglicóis/química , Espectrofotometria Ultravioleta , Nanomedicina Teranóstica
11.
Artigo em Inglês | MEDLINE | ID: mdl-32484683

RESUMO

The COVID-19 pandemic is currently causing a severe disruption and shortage in the global supply chain of necessary personal protective equipment (e.g., N95 respirators). The U.S. CDC has recommended use of household cloth by the general public to make cloth face coverings as a method of source control. We evaluated the filtration properties of natural and synthetic materials using a modified procedure for N95 respirator approval. Common fabrics of cotton, polyester, nylon, and silk had filtration efficiency of 5-25%, polypropylene spunbond had filtration efficiency 6-10%, and paper-based products had filtration efficiency of 10-20%. An advantage of polypropylene spunbond is that it can be simply triboelectrically charged to enhance the filtration efficiency (from 6 to >10%) without any increase in pressure (stable overnight and in humid environments). Using the filtration quality factor, fabric microstructure, and charging ability, we are able to provide an assessment of suggested fabric materials for homemade facial coverings.


Assuntos
Betacoronavirus , Infecções por Coronavirus/prevenção & controle , Máscaras , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Têxteis , Aerossóis , Microbiologia do Ar , Infecções por Coronavirus/transmissão , Eletricidade , Desenho de Equipamento , Filtração , Humanos , Máscaras/provisão & distribução , Microscopia Eletrônica de Varredura , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Nanotecnologia , Tamanho da Partícula , Equipamento de Proteção Individual/provisão & distribução , Pneumonia Viral/transmissão
12.
Int J Nanomedicine ; 15: 3281-3290, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32440124

RESUMO

Introduction: Cells exhibit high sensitivity and a diverse response to the nanotopography of the extracellular matrix, thereby endowing materials with instructive performances formerly reserved for growth factors. This finding leads to opportunities for improvement. However, the interplay between the topographical surface and cell behaviors remains incompletely understood. Methods: In the present study, we showed nanosurfaces with various dimensions of nanopits (200-750 nm) fabricated by self-assembling polystyrene (PS) nanospheres. Human adipose-derived stem cell behaviors, such as cell morphology, adhesion, cytoskeleton contractility, proliferation, and differentiation, were investigated on the prepared PS nanopit surface. Results: The osteogenic differentiation can be enhanced by nanopits with a diameter of 300-400 nm. Discussion: The present study provided exciting new avenues to investigate cellular responses to well-defined nanoscale topographic features, which could further guide bone tissue engineering and stem cell clinical research. The capability to control developing biomaterials mimicking nanotopographic surfaces promoted functional tissue engineering, such as artificial joint replacement, bone repair, and dental applications.


Assuntos
Tecido Adiposo/citologia , Diferenciação Celular , Nanoestruturas/química , Osteogênese , Poliestirenos/farmacologia , Células-Tronco/citologia , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Nanoestruturas/ultraestrutura , Osteogênese/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Células-Tronco/ultraestrutura
13.
Neuron ; 107(2): 257-273.e5, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32392471

RESUMO

The brain's complex microconnectivity underlies its computational abilities and vulnerability to injury and disease. It has been challenging to illuminate the features of this synaptic network due to the small size and dense packing of its elements. Here, we describe a rapid, accessible super-resolution imaging and analysis workflow-SEQUIN-that quantifies central synapses in human tissue and animal models, characterizes their nanostructural and molecular features, and enables volumetric imaging of mesoscale synaptic networks without the production of large histological arrays. Using SEQUIN, we identify cortical synapse loss resulting from diffuse traumatic brain injury, a highly prevalent connectional disorder. Similar synapse loss is observed in three murine models of Alzheimer-related neurodegeneration, where SEQUIN mesoscale mapping identifies regional synaptic vulnerability. These results establish an easily implemented and robust nano-to-mesoscale synapse quantification and characterization method. They furthermore identify a shared mechanism-synaptopathy-between Alzheimer neurodegeneration and its best-established epigenetic risk factor, brain trauma.


Assuntos
Lesões Encefálicas Traumáticas/patologia , Sistema Nervoso Central/diagnóstico por imagem , Nanoestruturas/ultraestrutura , Vias Neurais/diagnóstico por imagem , Vias Neurais/ultraestrutura , Neuroimagem/métodos , Sinapses/ultraestrutura , Animais , Mapeamento Encefálico , Sistema Nervoso Central/ultraestrutura , Córtex Cerebral/patologia , Humanos , Mamíferos , Camundongos
14.
Int J Nanomedicine ; 15: 2541-2553, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32368039

RESUMO

Background: In the emerging field of nanotechnology, copper oxide (CuO) nanomaterials are considered to be one of the most important transition metal oxides owing to its fascinating properties. Its synthesis from green chemistry principles is gaining importance as next-generation antibiotics due to its simplicity, eco-friendliness, and cost-effectiveness. In the present study, CuO nanorods (CuO NRs) were synthesized from the aqueous fruit extract of Momordica charantia and characterized using different analytical techniques. Further, the biomedical therapeutic potential was evaluated against multi-drug resistant microbial strains. Materials and Methods: To synthesize CuO NRs, 0.1M of CuSO4.5H2O solution was added to aqueous extract of Momordica charantia in a 1:3 (v/v) ratio (pH=11) and heated at 50°C followed by washing and drying. The synthesized CuO NRs were subjected to characterization using different analytical techniques such as UV visible spectroscopy, zeta sizer equipped with zeta potential, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). Further, the application as a biomedical therapeutic potential was evaluated in vitro using well diffusion method against eleven multidrug-resistant clinical bacterial strains, a fungus- Trichophyton rubrum and in ovo against the R2B virus using haemagglutination (HA) test. Results: Characterization was preliminarily done by the spectral study that confirms the absorbance band at 245nm. FTIR analysis at 628 cm-1 peak identified copper oxide vibration. SEM analysis revealed agglomerated particle clusters. However, with TEM clear nanorods of average diameter of 61.48 ± 2 nm were observed. EDAX confirmed CuO formation while XRD showed a typical monoclinic structure with 6 nm crystallite size. Biological screening of CuO NRs showed significant results against both in vitro and in ovo methods. Significant inhibitory activity (p<0.0001) was noted against most of the resistant human pathogenic strains including both Gram-positive and Gram-negative bacteria. The highest efficacy was observed against Bacillus cereus with a 31.66 mm zone of inhibition. Besides, the therapeutic potential of CuO NRs against Corynebacterium xerosis, Streptococcus viridians and R2B strain of Newcastle disease is reported for the first time. Conclusion: Based on the present results, it could be expected that green synthesized CuO NRs would find potential applications in the field of nanomedicine.


Assuntos
Antibacterianos/farmacologia , Cobre/farmacologia , Química Verde , Momordica charantia/química , Nanoestruturas/química , Animais , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Galinhas , Fungos/efeitos dos fármacos , Testes de Hemaglutinação , Humanos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Nanoestruturas/ultraestrutura , Nanotubos/química , Nanotubos/ultraestrutura , Tamanho da Partícula , Espectrometria por Raios X , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Difração de Raios X
15.
Nucleic Acids Res ; 48(9): 5135-5146, 2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32232413

RESUMO

Although the field of structural DNA nanotechnology has been advancing with an astonishing pace, de novo design of complex 3D nanostructures and functional devices remains a laborious and time-consuming process. One reason for that is the need for multiple cycles of experimental characterization to elucidate the effect of design choices on the actual shape and function of the self-assembled objects. Here, we demonstrate a multi-resolution simulation framework, mrdna, that, in 30 min or less, can produce an atomistic-resolution structure of a self-assembled DNA nanosystem. We demonstrate fidelity of our mrdna framework through direct comparison of the simulation results with the results of cryo-electron microscopy (cryo-EM) reconstruction of multiple 3D DNA origami objects. Furthermore, we show that our approach can characterize an ensemble of conformations adopted by dynamic DNA nanostructures, the equilibrium structure and dynamics of DNA objects constructed using off-lattice self-assembly principles, i.e. wireframe DNA objects, and to study the properties of DNA objects under a variety of environmental conditions, such as applied electric field. Implemented as an open source Python package, our framework can be extended by the community and integrated with DNA design and molecular graphics tools.


Assuntos
Simulação por Computador , DNA/química , Modelos Moleculares , Nanoestruturas/química , Microscopia Crioeletrônica , DNA/ultraestrutura , Nanoestruturas/ultraestrutura , Conformação de Ácido Nucleico
16.
Nat Commun ; 11(1): 1294, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32157090

RESUMO

Recently, it has been shown that animals such as jumping spiders, birds, and butterflies have evolved ultra-black coloration comparable to the blackest synthetic materials. Of these, certain papilionid butterflies have reflectances approaching 0.2%, resulting from a polydisperse honeycomb structure. It is unknown if other ultra-black butterflies use this mechanism. Here, we examine a phylogenetically diverse set of butterflies and demonstrate that other butterflies employ simpler nanostructures that achieve ultra-black coloration in scales thinner than synthetic alternatives. Using scanning electron microscopy, we find considerable interspecific variation in the geometry of the holes in the structures, and verify with finite-difference time-domain modeling that expanded trabeculae and ridges, found across ultra-black butterflies, reduce reflectance up to 16-fold. Our results demonstrate that butterflies produce ultra-black by creating a sparse material with high surface area to increase absorption and minimize surface reflection. We hypothesize that butterflies use ultra-black to increase the contrast of color signals.


Assuntos
Escamas de Animais/anatomia & histologia , Borboletas/anatomia & histologia , Nanoestruturas/química , Pigmentação , Escamas de Animais/ultraestrutura , Animais , Borboletas/ultraestrutura , Simulação por Computador , Nanoestruturas/ultraestrutura , Refratometria , Asas de Animais/anatomia & histologia
17.
Cell Prolif ; 53(4): e12787, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32162733

RESUMO

OBJECTIVES: To provide a new research direction for nerve regeneration and strategy for Alzheimer's disease treatment, tetrahedral DNA nanostructures (TDNs)-novel tetrahedral framework nucleic acid molecule nanoparticles (tFNA) that can inhibit the apoptosis of nerve cells are employed in the experiment. MATERIALS AND METHODS: To verify the successful preparation of TDNs, the morphology of TDNs was observed by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The expression of apoptosis-related genes and proteins was investigated by confocal microscope, flow cytometry, PCR and Western blot to detect the impact of TDNs on the Alzheimer's model. And finally, Morris water maze experiment was used to test behavioural changes and Nissl stain was detected to observe the morphology and quantity of neurons in the hippocampus. Immunofluorescence stain was used to observe the Aß stain, and TUNEL dyeing was utilized to observe neuronal apoptosis. RESULTS: In vitro and in vivo experiments confirm that TDNs, in a specific concentration range, have no toxic or side effects on nerve cells, can effectively inhibit apoptosis in an Alzheimer's disease cell model and effectively improve memory and learning ability in a rat model of Alzheimer's disease. CONCLUSIONS: These findings suggest that TDNs may be a promising drug for the treatment of Alzheimer's disease.


Assuntos
Doença de Alzheimer/tratamento farmacológico , DNA/uso terapêutico , Nanoestruturas/uso terapêutico , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/análise , Animais , Apoptose/efeitos dos fármacos , DNA/farmacocinética , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Aprendizagem/efeitos dos fármacos , Memória/efeitos dos fármacos , Modelos Moleculares , Nanoestruturas/ultraestrutura , Células PC12 , Ratos , Ratos Sprague-Dawley
18.
Nat Commun ; 11(1): 862, 2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-32054841

RESUMO

Complex hierarchical structure governs emergent properties in biopolymeric materials; yet, the material processing involved remains poorly understood. Here, we investigated the multi-scale structure and composition of the mussel byssus cuticle before, during and after formation to gain insight into the processing of this hard, yet extensible metal cross-linked protein composite. Our findings reveal that the granular substructure crucial to the cuticle's function as a wear-resistant coating of an extensible polymer fiber is pre-organized in condensed liquid phase secretory vesicles. These are phase-separated into DOPA-rich proto-granules enveloped in a sulfur-rich proto-matrix which fuses during secretion, forming the sub-structure of the cuticle. Metal ions are added subsequently in a site-specific way, with iron contained in the sulfur-rich matrix and vanadium coordinated by DOPA-catechol in the granule. We posit that this hierarchical structure self-organizes via phase separation of specific amphiphilic proteins within secretory vesicles, resulting in a meso-scale structuring that governs cuticle function.


Assuntos
Materiais Revestidos Biocompatíveis/química , Metaloproteínas/química , Mytilus edulis/química , Estruturas Animais/anatomia & histologia , Estruturas Animais/química , Estruturas Animais/ultraestrutura , Animais , Di-Hidroxifenilalanina/química , Imageamento Tridimensional , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Mytilus edulis/anatomia & histologia , Mytilus edulis/ultraestrutura , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Vesículas Secretórias/química , Vesículas Secretórias/ultraestrutura
19.
Macromol Rapid Commun ; 41(5): e1900555, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32003532

RESUMO

Structured color in nature is controlled by nano- and micro-structured interfaces giving rise to a photonic bandgap. This study presents a biomimetic optical material based on polymeric inverse opals that respond to enzyme activity. Polymer colloids provide a template in which acryloyl-functionalized poly(ethylene glycol) is integrated; dissolution of the colloids leads to a hydrogel inverse opal that can be lithographically patterned using transfer printing. Incorporating enzyme substrates within the voids provides a material that responds to the presence of proteases through a shift in the optical properties.


Assuntos
Materiais Biocompatíveis/química , Hidrogéis/química , Nanoestruturas/química , Peptídeo Hidrolases/metabolismo , Polímeros/química , Materiais Biomiméticos/química , Coloides/química , Cor , Iridescência , Microscopia Eletrônica de Varredura , Nanoestruturas/ultraestrutura , Fótons , Polietilenoglicóis/química , Polimetil Metacrilato/química , Impressão
20.
Macromol Rapid Commun ; 41(6): e1900586, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32022359

RESUMO

Orthogonal dynamic covalent self-assembly is used as a facile method for constructing polymer hollow nanocapsules (NCs) and thin films. The bifunctional precursor 4-formylphenylboronic acid is symmetrically installed with a boronic acid group for the boroxine linkage, and an aldehyde group for the Schiff base reaction which can react with twofold symmetry linkers ethylenediamine and para phenylenediamine to attain polymer NCs and nanosheets. Owing to the reversibility of the imine linkages, the mutual morphological transformation between polymer NCs and thin films via an amine-imine-exchange strategy is successfully achieved. Multiple reversible covalent bonds allow the control the release of the load in polymer NCs using different techniques. This may be useful for designing stimulus-responsive smart materials.


Assuntos
Benzaldeídos/química , Ácidos Borônicos/química , Etilenodiaminas/química , Iminas/química , Nanocápsulas/química , Fenilenodiaminas/química , Polímeros/química , Polímeros/síntese química , Aldeídos/química , Aminas/química , Nanocápsulas/ultraestrutura , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Bases de Schiff/química , Propriedades de Superfície
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