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2.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360543

RESUMO

Pregnancy is associated with hypercoagulation states and increased thrombotic risk, especially in women with thrombophilia. We combine atomic force microscopy (AFM) and flow cytometry to examine the morphology and nanomechanics of platelets derived from women with early pregnancy loss (EPL) and control pregnant (CP) and non-pregnant (CNP) women. Both control groups exhibit similar morphometric parameters (height and surface roughness) and membrane stiffness of platelets. EPL patients' platelets, on the other hand, are more activated than the control groups, with prominent cytoskeletal rearrangement. In particular, reduced membrane roughness (22.9 ± 6 nm vs. 39.1 ± 8 nm) (p < 0.05) and height (692 ± 128 nm vs. 1090 ± 131 nm) (p < 0.05), strong alteration in the membrane Young modulus, increased production of platelets' microparticles, and higher expression of procoagulant surface markers, as well as increased occurrence of thrombophilia (FVL, FII20210A, PLA1/A2, MTHFR C677T or 4G/5G PAI-1) polymorphisms were found. We suggest that the carriage of thrombophilic mutations triggers structural and nanomechanical abnormalities in platelets, resulting in their increased activation. The activation state of platelets can be well characterized by AFM, and the morphometric and nanomechanical characteristics might serve as a new criterion for evaluation of the cause of miscarriage and offer the prospect of an innovative approach serving for diagnostic purposes.


Assuntos
Aborto Habitual/patologia , Plaquetas/patologia , Nanoestruturas/química , Polimorfismo Genético , Trombofilia/complicações , Aborto Habitual/etiologia , Aborto Habitual/metabolismo , Adulto , Plaquetas/metabolismo , Estudos de Casos e Controles , Feminino , Humanos , Gravidez
3.
Molecules ; 26(16)2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34443336

RESUMO

We develop a suitable delivery system for niaouli essential oil (NEO) using a nanoemulsification method for acne vulgaris. Prepared nanoemulsions (NEs) were characterized for droplet dimension, rheology, surface charge, and stability. The ability of NEO formulations against Propionibacterium acnes and Staphylococcus epidermidis was investigated and all formulations showed antiacne potential in vitro. Ex vivo permeation studies indicated significant improvement in drug permeations and steady state flux of all NEO-NEs compared to the neat NEO (p < 0.05). On the basis of the studied pharmaceutical parameters, enhanced ex vivo skin permeation, and marked effect on acne pathogens, formulation NEO-NE4 was found to be the best (oil (NEO; 10% v/v); Kolliphor EL (9.25% v/v), Carbitol (27.75% v/v), and water (53% v/v)). Concisely, the in vitro and ex vivo results revealed that nanoemulsification improved the delivery as well as bioactivities of NEO significantly.


Assuntos
Portadores de Fármacos/química , Melaleuca/química , Nanoestruturas/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Emulsões , Óleos Voláteis/metabolismo , Permeabilidade , Pele/metabolismo , Staphylococcus epidermidis/efeitos dos fármacos
4.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360734

RESUMO

Biomimetic design provides novel opportunities for enhancing and functionalizing biomaterials. Here we created a zirconia surface with cactus-inspired meso-scale spikes and bone-inspired nano-scale trabecular architecture and examined its biological activity in bone generation and integration. Crisscrossing laser etching successfully engraved 60 µm wide, cactus-inspired spikes on yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) with 200-300 nm trabecular bone-inspired interwoven structures on the entire surface. The height of the spikes was varied from 20 to 80 µm for optimization. Average roughness (Sa) increased from 0.10 µm (polished smooth surface) to 18.14 µm (80 µm-high spikes), while the surface area increased by up to 4.43 times. The measured dimensions of the spikes almost perfectly correlated with their estimated dimensions (R2 = 0.998). The dimensional error of forming the architecture was 1% as a coefficient of variation. Bone marrow-derived osteoblasts were cultured on a polished surface and on meso- and nano-scale hybrid textured surfaces with different spike heights. The osteoblastic differentiation was significantly promoted on the hybrid-textured surfaces compared with the polished surface, and among them the hybrid-textured surface with 40 µm-high spikes showed unparalleled performance. In vivo bone-implant integration also peaked when the hybrid-textured surface had 40 µm-high spikes. The relationships between the spike height and measures of osteoblast differentiation and the strength of bone and implant integration were non-linear. The controllable creation of meso- and nano-scale hybrid biomimetic surfaces established in this study may provide a novel technological platform and design strategy for future development of biomaterial surfaces to improve bone integration and regeneration.


Assuntos
Materiais Biomiméticos , Diferenciação Celular/efeitos dos fármacos , Nanoestruturas/química , Osteoblastos/metabolismo , Osteogênese/efeitos dos fármacos , Zircônio , Animais , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Cactaceae , Masculino , Nanoestruturas/ultraestrutura , Osteoblastos/citologia , Ratos , Ratos Sprague-Dawley , Zircônio/química , Zircônio/farmacologia
5.
Int J Mol Sci ; 22(15)2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34360758

RESUMO

The current study describes the experimental design guided development of PEGylated nanoemulsions as parenteral delivery systems for curcumin, a powerful antioxidant, as well as the evaluation of their physicochemical characteristics and antioxidant activity during the two years of storage. Experimental design setup helped development of nanoemulsion templates with critical quality attributes in line with parenteral application route. Curcumin-loaded nanoemulsions showed mean droplet size about 105 nm, polydispersity index <0.15, zeta potential of -40 mV, and acceptable osmolality of about 550 mOsm/kg. After two years of storage at room temperature, all formulations remained stable. Moreover, antioxidant activity remained intact, as demonstrated by DPPH (IC50 values 0.078-0.075 mg/mL after two years) and FRAPS assays. In vitro release testing proved that PEGylated phospholipids slowed down the curcumin release from nanoemulsions. The nanoemulsion carrier has been proven safe by the MTT test conducted with MRC-5 cell line, and effective on LS cell line. Results from the pharmacokinetic pilot study implied the PEGylated nanoemulsions improved plasma residence of curcumin 20 min after intravenous administration, compared to the non-PEGylated nanoemulsion (two-fold higher) or curcumin solution (three-fold higher). Overall, conclusion suggests that developed PEGylated nanoemulsions present an acceptable delivery system for parenteral administration of curcumin, being effective in preserving its stability and antioxidant capacity at the level highly comparable to the initial findings.


Assuntos
Antioxidantes , Curcumina , Portadores de Fármacos , Nanoestruturas , Animais , Antioxidantes/química , Antioxidantes/farmacocinética , Antioxidantes/farmacologia , Disponibilidade Biológica , Linhagem Celular Tumoral , Curcumina/química , Curcumina/farmacocinética , Curcumina/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Emulsões , Humanos , Masculino , Nanoestruturas/química , Nanoestruturas/uso terapêutico , Projetos Piloto , Ratos , Ratos Sprague-Dawley
6.
ACS Appl Mater Interfaces ; 13(33): 39957-39966, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34376049

RESUMO

Microbial inoculants can enhance soil quality, promote plant nutrient acquisition, and alleviate problems caused by the excessive use of chemical fertilizers. However, susceptibility to harsh conditions during transport and storage, as well as the short shelf-life of plant growth-promoting rhizobacteria (PGPR), limit industrial application. Herein, a novel strategy to form nanocoating on bacterial surfaces to enhance viability was proposed. The nanocoating was composed of N-hydroxysuccinimide (NHS)-modified poly (γ-glutamic acid) (γ-PGA) and calcium ions, which could adhere to the surface of bacteria by forming covalent bonds and ionic bonds with the bacteria. The bacteria encapsulated in the coating had better resistance against harsh conditions than bare bacteria. The viability of coated bacteria was also increased by 2.38 times compared with bare bacteria after 4 weeks of storage. The pot experiment showed that coated Pseudomonas stutzeri NRCB010 had better growth-promoting properties compared with free P. stutzeri NRCB010. These results indicate that cell surface engineering is an effective method to enhance the resistance of bacteria against harsh conditions and is expected to promote the widespread use of PGPR.


Assuntos
Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/metabolismo , Nanoestruturas/química , Ácido Poliglutâmico/análogos & derivados , Pseudomonas stutzeri/metabolismo , Biotecnologia , Proliferação de Células/efeitos dos fármacos , Fertilizantes/microbiologia , Temperatura Alta , Engenharia Metabólica , Viabilidade Microbiana/efeitos dos fármacos , Desenvolvimento Vegetal/efeitos dos fármacos , Ácido Poliglutâmico/química , Ácido Poliglutâmico/metabolismo , Pseudomonas stutzeri/efeitos dos fármacos , Exposição à Radiação , Solo , Estresse Mecânico
7.
ACS Appl Mater Interfaces ; 13(33): 39711-39718, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34402304

RESUMO

The manufacture of DNA origami nanostructures with highly ordered functional motifs is of great significance for biomedical applications. Here, we present a robust strategy to produce customized scaffolds with integrated aptamer sequences, which enables direct construction of functional DNA origami structures. As we demonstrated, aptamers of various numbers and types were efficiently and stably integrated in user-defined positions of the scaffolds. Specifically, two different thrombin aptamer sequences were simultaneously inserted into the M13mp18 phage genome. The assembled functional DNA origami structures from this aptamer-integrated scaffold exhibited increased binding efficiency to thrombin and displayed more than 10-fold stronger resistance to exonuclease degradation than that produced using the traditional staple extension method. Additionally, a scaffold integrated with the platelet-derived growth factor aptamer was produced, and the assembled DNA origami structures showed significant inhibitory effect on breast cancer cells MDA-MB-231. This scalable method of creating design-specific scaffolds opens up a new way to construct more stable and functionally robust DNA origami structures and thus provides an important basis for their broader applications.


Assuntos
Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/metabolismo , DNA/química , Nanoestruturas/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Conformação de Ácido Nucleico , Trombina/química
8.
Molecules ; 26(16)2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34443385

RESUMO

DNA origami nanostructures (DONs) are promising substrates for the single-molecule investigation of biomolecular reactions and dynamics by in situ atomic force microscopy (AFM). For this, they are typically immobilized on mica substrates by adding millimolar concentrations of Mg2+ ions to the sample solution, which enable the adsorption of the negatively charged DONs at the like-charged mica surface. These non-physiological Mg2+ concentrations, however, present a serious limitation in such experiments as they may interfere with the reactions and processes under investigation. Therefore, we here evaluate three approaches to efficiently immobilize DONs at mica surfaces under essentially Mg2+-free conditions. These approaches rely on the pre-adsorption of different multivalent cations, i.e., Ni2+, poly-l-lysine (PLL), and spermidine (Spdn). DON adsorption is studied in phosphate-buffered saline (PBS) and pure water. In general, Ni2+ shows the worst performance with heavily deformed DONs. For 2D DON triangles, adsorption at PLL- and in particular Spdn-modified mica may outperform even Mg2+-mediated adsorption in terms of surface coverage, depending on the employed solution. For 3D six-helix bundles, less pronounced differences between the individual strategies are observed. Our results provide some general guidance for the immobilization of DONs at mica surfaces under Mg2+-free conditions and may aid future in situ AFM studies.


Assuntos
Silicatos de Alumínio/química , DNA/química , Magnésio/química , Microscopia de Força Atômica , Nanoestruturas/química , Conformação de Ácido Nucleico , Adsorção , Níquel/química , Polieletrólitos/química , Polilisina/química , Espermidina/química , Propriedades de Superfície , Água/química
9.
Int J Mol Sci ; 22(16)2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34445103

RESUMO

Here, we report the development of a novel photoactive biomolecular nanoarchitecture based on the genetically engineered extremophilic photosystem I (PSI) biophotocatalyst interfaced with a single layer graphene via pyrene-nitrilotriacetic acid self-assembled monolayer (SAM). For the oriented and stable immobilization of the PSI biophotocatalyst, an His6-tag was genetically engineered at the N-terminus of the stromal PsaD subunit of PSI, allowing for the preferential binding of this photoactive complex with its reducing side towards the graphene monolayer. This approach yielded a novel robust and ordered nanoarchitecture designed to generate an efficient direct electron transfer pathway between graphene, the metal redox center in the organic SAM and the photo-oxidized PSI biocatalyst. The nanosystem yielded an overall current output of 16.5 µA·cm-2 for the nickel- and 17.3 µA·cm-2 for the cobalt-based nanoassemblies, and was stable for at least 1 h of continuous standard illumination. The novel green nanosystem described in this work carries the high potential for future applications due to its robustness, highly ordered and simple architecture characterized by the high biophotocatalyst loading as well as simplicity of manufacturing.


Assuntos
Grafite/química , Microalgas/química , Nanoestruturas/química , Complexo de Proteína do Fotossistema I/química , Luz , Oxirredução/efeitos dos fármacos , Rodófitas/química , Transdução de Sinais/efeitos dos fármacos
10.
Nat Commun ; 12(1): 4743, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362911

RESUMO

Biology has evolved a variety of agents capable of permeabilizing and disrupting lipid membranes, from amyloid aggregates, to antimicrobial peptides, to venom compounds. While often associated with disease or toxicity, these agents are also central to many biosensing and therapeutic technologies. Here, we introduce a class of synthetic, DNA-based particles capable of disrupting lipid membranes. The particles have finely programmable size, and self-assemble from all-DNA and cholesterol-DNA nanostructures, the latter forming a membrane-adhesive core and the former a protective hydrophilic corona. We show that the corona can be selectively displaced with a molecular cue, exposing the 'sticky' core. Unprotected particles adhere to synthetic lipid vesicles, which in turn enhances membrane permeability and leads to vesicle collapse. Furthermore, particle-particle coalescence leads to the formation of gel-like DNA aggregates that envelop surviving vesicles. This response is reminiscent of pathogen immobilisation through immune cells secretion of DNA networks, as we demonstrate by trapping E. coli bacteria.


Assuntos
Bactérias/metabolismo , DNA/química , Lipídeos de Membrana/química , Permeabilidade da Membrana Celular , Escherichia coli/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Lipídeos de Membrana/metabolismo , Nanoestruturas/química , Tamanho da Partícula , Proteínas Citotóxicas Formadoras de Poros
11.
Molecules ; 26(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34361740

RESUMO

There is a challenging need for the development of new alternative nanostructures that can allow the coupling and/or encapsulation of therapeutic/diagnostic molecules while reducing their toxicity and improving their circulation and in-vivo targeting. Among the new materials using natural building blocks, peptides have attracted significant interest because of their simple structure, relative chemical and physical stability, diversity of sequences and forms, their easy functionalization with (bio)molecules and the possibility of synthesizing them in large quantities. A number of them have the ability to self-assemble into nanotubes, -spheres, -vesicles or -rods under mild conditions, which opens up new applications in biology and nanomedicine due to their intrinsic biocompatibility and biodegradability as well as their surface chemical reactivity via amino- and carboxyl groups. In order to obtain nanostructures suitable for biomedical applications, the structure, size, shape and surface chemistry of these nanoplatforms must be optimized. These properties depend directly on the nature and sequence of the amino acids that constitute them. It is therefore essential to control the order in which the amino acids are introduced during the synthesis of short peptide chains and to evaluate their in-vitro and in-vivo physico-chemical properties before testing them for biomedical applications. This review therefore focuses on the synthesis, functionalization and characterization of peptide sequences that can self-assemble to form nanostructures. The synthesis in batch or with new continuous flow and microflow techniques will be described and compared in terms of amino acids sequence, purification processes, functionalization or encapsulation of targeting ligands, imaging probes as well as therapeutic molecules. Their chemical and biological characterization will be presented to evaluate their purity, toxicity, biocompatibility and biodistribution, and some therapeutic properties in vitro and in vivo. Finally, their main applications in the biomedical field will be presented so as to highlight their importance and advantages over classical nanostructures.


Assuntos
Materiais Biocompatíveis/síntese química , Portadores de Fármacos/síntese química , Nanoestruturas/química , Peptídeos/síntese química , Técnicas de Síntese em Fase Sólida/métodos , Sequência de Aminoácidos , Animais , Materiais Biocompatíveis/farmacocinética , Portadores de Fármacos/farmacocinética , Composição de Medicamentos/métodos , Humanos , Nanoestruturas/administração & dosagem , Nanoestruturas/ultraestrutura , Tamanho da Partícula , Peptídeos/farmacocinética , Distribuição Tecidual
12.
Nucleic Acids Res ; 49(15): 8987-8999, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34358322

RESUMO

Single molecule force spectroscopy is a powerful approach to probe the structure, conformational changes, and kinetic properties of biological and synthetic macromolecules. However, common approaches to apply forces to biomolecules require expensive and cumbersome equipment and relatively large probes such as beads or cantilevers, which limits their use for many environments and makes integrating with other methods challenging. Furthermore, existing methods have key limitations such as an inability to apply compressive forces on single molecules. We report a nanoscale DNA force spectrometer (nDFS), which is based on a DNA origami hinge with tunable mechanical and dynamic properties. The angular free energy landscape of the nDFS can be engineered across a wide range through substitution of less than 5% of the strand components. We further incorporate a removable strut that enables reversible toggling of the nDFS between open and closed states to allow for actuated application of tensile and compressive forces. We demonstrate the ability to apply compressive forces by inducing a large bend in a 249bp DNA molecule, and tensile forces by inducing DNA unwrapping of a nucleosome sample. These results establish a versatile tool for force spectroscopy and robust methods for designing nanoscale mechanical devices with tunable force application.


Assuntos
DNA/química , Nanoestruturas/química , Bioengenharia , Fenômenos Biomecânicos , Nucleossomos/química , Análise Espectral
13.
J Phys Chem Lett ; 12(33): 8039-8045, 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34402624

RESUMO

Calcite dissolution is initiated by the formation of a nanoscale etch pit followed by step edge propagation and hence strongly influenced by the interactions between surface diffusing ions and step edges. However, such atomic-scale dynamics are mostly inaccessible with current imaging tools. Here, we overcome this limitation by using our recent development of high-speed frequency modulation atomic force microscopy. By visualizing atomic-scale structural changes of the etch pits at the calcite surface in water, we found the existence of mobile and less-mobile surface adsorption layers (SALs) in the etch pits. We also found that some etch pits maintain their size for a long time without expansion, and their step edges are often associated with less-mobile SALs, suggesting their step stabilization effect.


Assuntos
Carbonato de Cálcio/química , Microscopia de Força Atômica/métodos , Nanoestruturas/química , Adsorção , Cristalografia , Estrutura Molecular , Solubilidade , Propriedades de Superfície , Água/química
14.
Molecules ; 26(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34443412

RESUMO

Palmarosa essential oil (PEO) is an alternative to synthetic fungicides to control the contamination by food-deteriorating fungi, such as Aspergillus nomius. Nonetheless, the low long-term stability and volatility hamper its utilization. Thus, this study aimed to develop nanostructured lipid carriers (NLCs) containing PEO to improve its stability and consequently prolong the activity against A. nomius. A mixture design was applied to find the best preparation conditions for antifungal activity. The characterization analyses included size measurements, zeta potential (ζ-potential), entrapment efficiency (EE), and antifungal activity (by inhibition of mycelial growth (IMG) and/or in situ test (pre-contaminated Brazil nuts) tests). The nanocarriers presented particle sizes smaller than 300 nm, homogeneous size distribution, ζ-potential of -25.19 to -41.81 mV, and EE between 73.6 and 100%. The formulations F5 and F10 showed the highest IMG value (98.75%). Based on the regression model, three optimized formulations (OFs) were tested for antifungal activity (IMG and in situ test), which showed 100% of inhibition and prevented the deterioration of Brazil nuts by A. nomius. The preliminary stability test showed the maintenance of antifungal activity and physicochemical characteristics for 90 days. These results suggest a promising system as a biofungicide against A. nomius.


Assuntos
Aspergillus/efeitos dos fármacos , Cymbopogon/química , Portadores de Fármacos/química , Nanoestruturas/química , Óleos Voláteis/farmacologia , Antifúngicos/farmacologia , Bertholletia/microbiologia , Composição de Medicamentos , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Nanoestruturas/ultraestrutura , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática
15.
Int J Mol Sci ; 22(15)2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34361117

RESUMO

It is acknowledged that the physicochemical properties of nanomaterials (NMs) have an impact on their toxicity and, eventually, their pathogenicity. These properties may include the NMs' surface chemical composition, size, shape, surface charge, surface area, and surface coating with ligands (which can carry different functional groups as well as proteins). Nanotopography, defined as the specific surface features at the nanoscopic scale, is not widely acknowledged as an important physicochemical property. It is known that the size and shape of NMs determine their nanotopography which, in turn, determines their surface area and their active sites. Nanotopography may also influence the extent of dissolution of NMs and their ability to adsorb atoms and molecules such as proteins. Consequently, the surface atoms (due to their nanotopography) can influence the orientation of proteins as well as their denaturation. However, although it is of great importance, the role of surface topography (nanotopography) in nanotoxicity is not much considered. Many of the issues that relate to nanotopography have much in common with the fundamental principles underlying classic catalysis. Although these were developed over many decades, there have been recent important and remarkable improvements in the development and study of catalysts. These have been brought about by new techniques that have allowed for study at the nanoscopic scale. Furthermore, the issue of quantum confinement by nanosized particles is now seen as an important issue in studying nanoparticles (NPs). In catalysis, the manipulation of a surface to create active surface sites that enhance interactions with external molecules and atoms has much in common with the interaction of NP surfaces with proteins, viruses, and bacteria with the same active surface sites of NMs. By reviewing the role that surface nanotopography plays in defining many of the NMs' surface properties, it reveals the need for its consideration as an important physicochemical property in descriptive and predictive toxicology. Through the manipulation of surface topography, and by using principles developed in catalysis, it may also be possible to make safe-by-design NMs with a reduction of the surface properties which contribute to their toxicity.


Assuntos
Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Nanoestruturas/química , Nanoestruturas/toxicidade , Catálise , Nanoestruturas/administração & dosagem , Propriedades de Superfície
16.
J Chem Phys ; 155(5): 055102, 2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34364335

RESUMO

Ratcheted multi-step hopping electron transfer systems can plausibly produce directional charge transport over very large distances without requiring a source-drain voltage bias. We examine molecular strategies to realize ratcheted charge transport based on multi-step charge hopping, and we illustrate two ratcheting mechanisms with examples based on DNA structures. The charge transport times and currents that may be generated in these assemblies are also estimated using kinetic simulations. The first ratcheting mechanism described for nanoscale systems requires local electric fields on the 109 V/m scale to realize nearly 100% population transport. The second ratcheting mechanism for even larger systems, based on electrochemical gating, is estimated to generate currents as large as 0.1 pA for DNA structures that are a few µm in length with a gate voltage of about 5 V, a magnitude comparable to currents measured in DNA wires at the nanoscale when a source-drain voltage bias of similar magnitude is applied, suggesting an approach to considerably extend the distance range over which DNA charge transport devices may operate.


Assuntos
DNA/química , Nanoestruturas/química , Condutividade Elétrica , Eletroquímica , Cinética , Eletricidade Estática
17.
Nat Commun ; 12(1): 4849, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381032

RESUMO

Although various artificial protein nanoarchitectures have been constructed, controlling the transformation between different protein assemblies has largely been unexplored. Here, we describe an approach to realize the self-assembly transformation of dimeric building blocks by adjusting their geometric arrangement. Thermotoga maritima ferritin (TmFtn) naturally occurs as a dimer; twelve of these dimers interact with each other in a head-to-side manner to generate 24-meric hollow protein nanocage in the presence of Ca2+ or PEG. By tuning two contiguous dimeric proteins to interact in a fully or partially side-by-side fashion through protein interface redesign, we can render the self-assembly transformation of such dimeric building blocks from the protein nanocage to filament, nanorod and nanoribbon in response to multiple external stimuli. We show similar dimeric protein building blocks can generate three kinds of protein materials in a manner that highly resembles natural pentamer building blocks from viral capsids that form different protein assemblies.


Assuntos
Nanoestruturas/química , Proteínas/química , Cálcio/química , Ferritinas/química , Nanoestruturas/ultraestrutura , Nanotecnologia , Polietilenoglicóis/química , Multimerização Proteica , Thermotoga maritima
18.
Int J Mol Sci ; 22(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34445294

RESUMO

Coupling of cells to biomaterials is a prerequisite for most biomedical applications; e.g., neuroelectrodes can only stimulate brain tissue in vivo if the electric signal is transferred to neurons attached to the electrodes' surface. Besides, cell survival in vitro also depends on the interaction of cells with the underlying substrate materials; in vitro assays such as multielectrode arrays determine cellular behavior by electrical coupling to the adherent cells. In our study, we investigated the interaction of neurons and glial cells with different electrode materials such as TiN and nanocolumnar TiN surfaces in contrast to gold and ITO substrates. Employing single-cell force spectroscopy, we quantified short-term interaction forces between neuron-like cells (SH-SY5Y cells) and glial cells (U-87 MG cells) for the different materials and contact times. Additionally, results were compared to the spreading dynamics of cells for different culture times as a function of the underlying substrate. The adhesion behavior of glial cells was almost independent of the biomaterial and the maximum growth areas were already seen after one day; however, adhesion dynamics of neurons relied on culture material and time. Neurons spread much better on TiN and nanocolumnar TiN and also formed more neurites after three days in culture. Our designed nanocolumnar TiN offers the possibility for building miniaturized microelectrode arrays for impedance spectroscopy without losing detection sensitivity due to a lowered self-impedance of the electrode. Hence, our results show that this biomaterial promotes adhesion and spreading of neurons and glial cells, which are important for many biomedical applications in vitro and in vivo.


Assuntos
Interfaces Cérebro-Computador , Neuroglia/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Titânio/farmacologia , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Matriz Extracelular/química , Ouro/química , Ouro/farmacologia , Humanos , Teste de Materiais , Nanoestruturas/química , Neuritos/efeitos dos fármacos , Neuritos/fisiologia , Neuroglia/fisiologia , Neurônios/fisiologia , Compostos de Estanho/química , Compostos de Estanho/farmacologia , Titânio/química
19.
Molecules ; 26(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208209

RESUMO

Encapsulation can be a suitable strategy to protect natural antimicrobial substances against some harsh conditions of processing and storage and to provide efficient formulations for antimicrobial delivery. Lipid-based nanostructures, including liposomes, solid lipid nanoparticles (SLNs), and nanostructured lipid nanocarriers (NLCs), are valuable systems for the delivery and controlled release of natural antimicrobial substances. These nanostructures have been used as carriers for bacteriocins and other antimicrobial peptides, antimicrobial enzymes, essential oils, and antimicrobial phytochemicals. Most studies are conducted with liposomes, although the potential of SLNs and NLCs as antimicrobial nanocarriers is not yet fully established. Some studies reveal that lipid-based formulations can be used for co-encapsulation of natural antimicrobials, improving their potential to control microbial pathogens.


Assuntos
Anti-Infecciosos/administração & dosagem , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Lipídeos/química , Lipossomos/química , Nanoestruturas/química , Anti-Infecciosos/química , Lipossomos/administração & dosagem , Nanoestruturas/administração & dosagem
20.
AAPS PharmSciTech ; 22(5): 204, 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34258696

RESUMO

Hirsutism is a dermatological condition that refers to the excessive growth of hair in androgen-sensitive areas in women. Recently, the enhancement of the visible signs of a hairy female has taken special concern that affected the quality of life. The present study was developed to compare the follicular targeting effect of topical spironolactone (SP) or progesterone (PG)-loaded nanostructured lipid carrier (NLC) on the management of hirsutism. Four NLC formulations were prepared using cold homogenization techniques and pharmaceutically evaluated. SP-NLC and PG-NLC topical hydrogels were prepared to explore their pharmacological effect on letrozole induced polycystic ovarian syndrome (PCOS) in rats. Inflammatory mediators, antioxidant, and hormonal parameters were assayed. Additionally, histopathological examination was carried out to confirm the successful induction of PCOS. Results confirmed that all NLC formulations have a spherical shape with particle size ranged from 225.92 ± 0.41 to 447.80 ± 0.66 nm, entrapment efficiency > 75%, and zeta potential (- 31.4 to - 36.5 mV). F1 and F3 NLCs were considered as selected formulations for SP and PG, respectively. Female Wistar rats treated with F1 formulation for 3 weeks displayed better outcomes as manifested by the measured parameters as compared to the other tested groups. A significant reduction in hair follicle diameter and density was observed after topical application of SP or PG nano-gels. Finally, the outcomes pose a strong argument that the development of topically administered SP-NLC can be explored as a promising carrier over PG-NLC for more effectual improvement in the visible sign of hirsutism.


Assuntos
Portadores de Fármacos/administração & dosagem , Hirsutismo/sangue , Hirsutismo/tratamento farmacológico , Nanoestruturas/administração & dosagem , Progesterona/administração & dosagem , Espironolactona/administração & dosagem , Animais , Portadores de Fármacos/síntese química , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Hidrogéis/administração & dosagem , Hidrogéis/síntese química , Inflamação/tratamento farmacológico , Inflamação/patologia , Nanoestruturas/química , Tamanho da Partícula , Progesterona/síntese química , Ratos , Ratos Wistar , Espironolactona/síntese química
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