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1.
Nat Commun ; 11(1): 4848, 2020 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-32973166

RESUMO

Polydopamine (PDA) is a simple and versatile conformal coating material that has been proposed for a variety of uses; however in practice its performance is often hindered by poor mechanical properties and high roughness. Here, we show that blue-diode laser annealing dramatically improves mechanical performance and reduces roughness of PDA coatings. Laser-annealed PDA (LAPDA) was shown to be >100-fold more scratch resistant than pristine PDA and even better than hard inorganic substrates, which we attribute to partial graphitization and covalent coupling between PDA subunits during annealing. Moreover, laser annealing provides these benefits while preserving other attractive properties of PDA, as demonstrated by the superior biofouling resistance of antifouling polymer-grafted LAPDA compared to PDA modified with the same polymer. Our work suggests that laser annealing may allow the use of PDA in mechanically demanding applications previously considered inaccessible, without sacrificing the functional versatility that is so characteristic of PDA.


Assuntos
Indóis/química , Indóis/efeitos da radiação , Lasers , Polímeros/química , Polímeros/efeitos da radiação , Incrustação Biológica , Materiais Revestidos Biocompatíveis/química , Teste de Materiais , Propriedades de Superfície
2.
Nat Commun ; 11(1): 4536, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32913189

RESUMO

Natural musculoskeletal systems have been widely recognized as an advanced robotic model for designing robust yet flexible microbots. However, the development of artificial musculoskeletal systems at micro-nanoscale currently remains a big challenge, since it requires precise assembly of two or more materials of distinct properties into complex 3D micro/nanostructures. In this study, we report femtosecond laser programmed artificial musculoskeletal systems for prototyping 3D microbots, using relatively stiff SU-8 as the skeleton and pH-responsive protein (bovine serum albumin, BSA) as the smart muscle. To realize the programmable integration of the two materials into a 3D configuration, a successive on-chip two-photon polymerization (TPP) strategy that enables structuring two photosensitive materials sequentially within a predesigned configuration was proposed. As a proof-of-concept, we demonstrate a pH-responsive spider microbot and a 3D smart micro-gripper that enables controllable grabbing and releasing. Our strategy provides a universal protocol for directly printing 3D microbots composed of multiple materials.


Assuntos
Biomimética/métodos , Compostos de Epóxi/efeitos da radiação , Fenômenos Fisiológicos Musculoesqueléticos , Polímeros/efeitos da radiação , Robótica/métodos , Soroalbumina Bovina/efeitos da radiação , Biomimética/instrumentação , Compostos de Epóxi/química , Hidrogéis/química , Hidrogéis/efeitos da radiação , Concentração de Íons de Hidrogênio , Lasers , Polimerização/efeitos da radiação , Polímeros/química , Impressão Tridimensional , Robótica/instrumentação , Soroalbumina Bovina/química
3.
Macromol Rapid Commun ; 41(15): e2000249, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32608545

RESUMO

A thermo-responsive conjugated polymer, PFBT-gPA is synthesized by grafting the poly(N-isopropylacrylamide) (PNIPAAm) to the side chains of a conjugated polyfluorene derivative through atom transfer radical polymerization (ATRP). PFBT-gPA undergoes a reversible phase transition in water below and above the lower critical solution temperature (LCST) and the process is studied by differential scanning calorimetry (DSC) analysis and UV/vis absorption spectra. PFBT-gPA shows a good photostability under UV light irradiation especially above the LCST. Moreover, the photosensitizing performance of PFBT-gPA could be tuned simply by changing temperature. The unique properties of PFBT-gPA promise its potential applications in sensing and photodynamic therapy.


Assuntos
Resinas Acrílicas/química , Fluorenos/química , Polímeros/química , Varredura Diferencial de Calorimetria , Espectroscopia de Ressonância Magnética , Transição de Fase , Fotodegradação , Fármacos Fotossensibilizantes/química , Polimerização , Polímeros/síntese química , Polímeros/efeitos da radiação , Espectrometria de Fluorescência , Temperatura , Água/química
4.
Macromol Rapid Commun ; 41(15): e2000314, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32608550

RESUMO

Light induced degradation of polymers has drawn increasing interest due to the need for externally controllable modulation of materials properties. However, the portfolio of polymers, that undergo precisely controllable degradation, is limited and typically requires UV light. A novel class of backbone-degradable polymers that undergo aerobic degradation in the presence of visible light, yet remain stable against broad-spectrum light under anaerobic conditions is reported. In this design, the polymer backbone is comprised of 9,10-dialkoxyanthracene units that are selectively cleaved by singlet oxygen in the presence of green light as confirmed by NMR and UV/vis spectroscopy. The resulting polymers have been processed by electrohydrodynamic (EHD) co-jetting into bicompartmental microfibers, where one hemisphere is selectively degraded on demand.


Assuntos
Antracenos/química , Polímeros/química , Polímeros/efeitos da radiação , Luz , Espectroscopia de Ressonância Magnética , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Oxigênio Singlete/química , Análise Espectral , Raios Ultravioleta
5.
Talanta ; 212: 120797, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32113559

RESUMO

We report here sensitive photoelectrochemical immunosensing of Staphylococcus aureus (S. aureus) using ZnS-Ag2S/polydopamine (PDA) as a novel photoelectric material and Cu2O as the peroxidase mimic tag. ZnS-Ag2S heterojunctions were prepared on indium tin oxide (ITO) via electrodeposition of ZnS nanoparticles, followed by silver ion exchange. To prepare a PDA/ZnS-Ag2S/ITO, the ZnS-Ag2S/ITO electrode was coated with PDA by self-polymerization of dopamine. The photocurrent of the PDA/ZnS-Ag2S/ITO is 1.55 times that of the ZnS-Ag2S/ITO and 7.87 times that of the ZnS/ITO, indicating a high-performance photoelectric material. A sandwiched-type photoelectrochemical immunosensor was constructed by using PDA/ZnS-Ag2S/ITO as the photoelectrode and Cu2O nanocubes as the labels. Cu2O nanocubes can serve as peroxidase mimic to generate catalytic precipitates on the immunoelectrodes, and both the Cu2O nanocubes and the generated precipitates can decrease the photocurrents of the immunoelectrodes, so a photoelectrochemical immunosensor for detecting S. aureus was constructed, showing a linear range between 10 and 107 CFU mL-1 and a low detection limit of 2 CFU mL-1. Owing to the signal amplification of Cu2O labeling, the sensitivity of the Cu2O-labeled immunosensor is 4 times that of a label-free immunosensor for detecting S. aureus, and the detection limit (2 CFU mL-1) is lower than that of a label-free immunosensor (10 CFU mL-1). This work not only provides a new and efficient photoelectric material but also demonstrated an efficient signal-amplification strategy for photoelectrochemical biosensing.


Assuntos
Cobre/química , Imunoensaio/métodos , Indóis/química , Nanopartículas Metálicas/química , Polímeros/química , Staphylococcus aureus/isolamento & purificação , Anticorpos Imobilizados/imunologia , Técnicas Biossensoriais/métodos , Catálise , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Indóis/efeitos da radiação , Luz , Limite de Detecção , Nanopartículas Metálicas/efeitos da radiação , Polímeros/efeitos da radiação , Compostos de Prata/química , Compostos de Prata/efeitos da radiação , Staphylococcus aureus/imunologia , Sulfetos/química , Sulfetos/efeitos da radiação , Compostos de Estanho/química , Compostos de Zinco/química , Compostos de Zinco/efeitos da radiação
6.
Macromol Rapid Commun ; 41(6): e1900607, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32037620

RESUMO

The synthesis of a photoresponsive amphiphilic diblock quarterpolymer containing 5-vinyl-1-naphthol (VN) as a photostable photoacidic comonomer is presented. The preparation is realized via a sequential reversible addition fragmentation chain transfer (RAFT) polymerization starting from a nona(ethylene glycol) methyl ether methacrylate (MEO9 MA/"O") hydrophilic block, which is then used as a macro-RAFT agent in the terpolymerization of styrene (S), 2-vinylpyridine (2VP), and TBS-protected VN (tVN). The terpolymerization proceeds in a controlled fashion and two diblock quarterpolymers, P(Om )-b-P(Sx -co-2VPy -co-VNz ), with varying functional comonomer compositions are prepared. These diblock quarterpolymers form spherical core-corona micelles in aqueous media according to dynamic light scattering (DLS) and cryogenic transmission electron microscopy (cryo-TEM). Upon irradiation, the photoacids within the micellar core experience a drastic increase in acidity causing a proton transfer from the photoacid to neighboring 2VP units. As a result, the hydrophilic/hydrophobic balance of the entire assembly is shifted, and the encapsulated cargo is released.


Assuntos
Naftóis/química , Polímeros/química , Polímeros/síntese química , Difusão Dinâmica da Luz , Etilenoglicóis/química , Interações Hidrofóbicas e Hidrofílicas , Luz , Micelas , Microscopia Eletrônica de Transmissão , Poli-Hidroxietil Metacrilato/química , Polimerização , Polímeros/efeitos da radiação , Piridinas/química , Estireno/química , Água/química
7.
Nat Commun ; 11(1): 1083, 2020 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-32107386

RESUMO

Methanol is a clean liquid energy carrier of sunshine and a key platform chemical for the synthesis of olefins and aromatics. Herein, we report the conversion of biomass-derived polyols and sugars into methanol and syngas (CO+H2) via UV light irradiation under room temperature, and the bio-syngas can be further used for the synthesis of methanol. The cellulose and even raw wood sawdust could be converted into methanol or syngas after hydrogenolysis or hydrolysis pretreatment. We find Cu dispersed on titanium oxide nanorod (TNR) rich in defects is effective for the selective C-C bond cleavage to methanol. Methanol is obtained from glycerol with a co-production of H2. A syngas with CO selectivity up to 90% in the gas phase is obtained via controlling the energy band structure of Cu/TNR.


Assuntos
Biocombustíveis , Biomassa , Nanotubos/química , Raios Ultravioleta , Monóxido de Carbono/efeitos da radiação , Catálise/efeitos da radiação , Celulose/química , Celulose/efeitos da radiação , Cobre/química , Hidrólise , Metanol/síntese química , Metanol/efeitos da radiação , Nitrogênio/efeitos da radiação , Polímeros/química , Polímeros/efeitos da radiação , Açúcares/química , Açúcares/efeitos da radiação , Titânio/química , Madeira/química , Madeira/efeitos da radiação
8.
Chem Commun (Camb) ; 56(7): 1093-1096, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31894764

RESUMO

We prepared novel conjugated polymer based NIR-II nanoparticles, which display extremely high photothermal conversion efficiency (65%). Both in vitro and in vivo investigations revealed that the as-prepared nanoparticles exhibit excellent theranostic properties including an extremely high cancer cell killing ability, admirable tumor elimination efficiency (100%) and a remarkable photoacoustic imaging contrast enhancing ability.


Assuntos
Antineoplásicos/uso terapêutico , Nanopartículas/uso terapêutico , Compostos de Organossilício/uso terapêutico , Polímeros/uso terapêutico , Tiadiazóis/uso terapêutico , Animais , Antineoplásicos/química , Antineoplásicos/efeitos da radiação , Células Hep G2 , Humanos , Hipertermia Induzida/métodos , Raios Infravermelhos , Camundongos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Nanopartículas/química , Nanopartículas/efeitos da radiação , Compostos de Organossilício/química , Compostos de Organossilício/efeitos da radiação , Técnicas Fotoacústicas/métodos , Polímeros/química , Polímeros/efeitos da radiação , Nanomedicina Teranóstica/métodos , Tiadiazóis/química , Tiadiazóis/efeitos da radiação
9.
ACS Sens ; 4(12): 3291-3297, 2019 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-31789504

RESUMO

Water sensors are a type of level sensor that can be used in various applications requiring the sensing of water levels, such as in dams, nuclear power plants, water pipes, water tanks, and dehumidifiers. In particular, water sensors in water ingress monitoring systems (WIMS) protect lives and property from disasters caused by water leakage and flooding. Here, a resistive water sensor for WIMS that incorporates poly(3,4-ethylenedioxythinophene):poly(styrene sulfonate) (PEDOT:PSS) grafted with poly(ethylene glycol) methyl ether (PEGME) (PEDOT:PSS-g-PEGME copolymer) as high-conductivity electrodes and laser-treated PEDOT:PSS-g-PEGME copolymer as the low-conductivity resistive component is reported. The configuration of the water sensor is modeled as two parallel resistors (Rlaser treated PEDOT:PSS||Rwater) when water comes into contact with the sensor surface. The two-resistor configuration exhibits a better performance in comparison with single-resistor configurations comprising only PEDOT:PSS-g-PEGME copolymer or laser-treated PEDOT:PSS-g-PEMGE copolymer. Moreover, PEDOT:PSS-g-PEGME copolymer is applied to the sensor to improve the stability of PEDOT:PSS in water. We demonstrate that the sensor can detect the water level in real time with high sensitivity and accuracy, and thus has potential in applications for monitoring water-related hazards.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/química , Técnicas Eletroquímicas/métodos , Polietilenoglicóis/química , Polímeros/química , Poliestirenos/química , Água/análise , Compostos Bicíclicos Heterocíclicos com Pontes/efeitos da radiação , Técnicas Eletroquímicas/instrumentação , Eletrodos , Raios Infravermelhos , Lasers , Polietilenoglicóis/efeitos da radiação , Polietilenotereftalatos/química , Polímeros/efeitos da radiação , Poliestirenos/efeitos da radiação
10.
Nat Commun ; 10(1): 4819, 2019 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-31645565

RESUMO

The motion of artificial molecular machines has been amplified into the shape transformation of polymer materials that have been compared to muscles, where mechanically active molecules work together to produce a contraction. In spite of this progress, harnessing cooperative molecular motion remains a challenge in this field. Here, we show how the light-induced action of artificial molecular switches modifies not only the shape but also, simultaneously, the stiffness of soft materials. The heterogeneous design of these materials features inclusions of free liquid crystal in a liquid crystal polymer network. When the magnitude of the intrinsic interfacial tension is modified by the action of the switches, photo-stiffening is observed, in analogy with the mechanical response of activated muscle fibers, and in contrast to melting mechanisms reported so far. Mechanoadaptive materials that are capable of active tuning of rigidity will likely contribute to a bottom-up approach towards human-friendly and soft robotics.


Assuntos
Órgãos Artificiais , Dureza/efeitos da radiação , Cristais Líquidos/química , Fenômenos Mecânicos , Fibras Musculares Esqueléticas , Músculo Esquelético , Polímeros/química , Raios Ultravioleta , Cristais Líquidos/efeitos da radiação , Contração Muscular , Polímeros/efeitos da radiação , Estresse Mecânico
11.
J Am Chem Soc ; 141(44): 17909-17917, 2019 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-31617714

RESUMO

Here, we present a method for the building of new bicyclic heterometallic cross-linked supramolecular polymers by hierarchical unification of three types of orthogonal noncovalent interactions, including platinum(II)-pyridine coordination-driven self-assembly, zinc-terpyridine complex, and host-guest interactions. The platinum-pyridine coordination provides the primary driving force to form discrete rhomboidal metallacycles. The assembly does not interfere with the zinc-terpyridine complexes, which link the discrete metallacycles into linear supramolecular polymers, and the conjugation length is extended upon the formation of the zinc-terpyridine complexes, which red-shifts the absorption and emission spectra. Finally, host-guest interactions via bis-ammonium salt binding to the benzo-21-crown-7 (B21C7) groups on the platinum acceptors afford the cross-linked supramolecular polymers. By continuous increase of the concentration of the supramolecular polymer to a relatively high level, supramolecular polymer gel is obtained, which exhibits self-healing properties and reversible gel-sol transitions stimulated by various external stimuli, including temperature, K+, and cyclen. Moreover, the photophysical properties of the supramolecular polymers could be effectively tuned by varying the substituents of the precursor ligands.


Assuntos
Substâncias Macromoleculares/química , Polímeros/química , Complexos de Coordenação/química , Éteres de Coroa/química , Luz , Substâncias Macromoleculares/efeitos da radiação , Platina/química , Polímeros/efeitos da radiação , Piridinas/química , Zinco/química
12.
J Mater Chem B ; 7(42): 6576-6584, 2019 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-31588950

RESUMO

NIR-II fluorescence imaging has great potential in diagnosis, but the quantum efficiency of contrast agents is an urgent problem to be solved. We synthesized two new multifunctional polymers, P-TT and P-DPP, with a tetrahedral C (sp3) and branched alkyl chains in the main chain, which were beneficial to obtain high quantum efficiency. P-TT and P-DPP showed absorption peaks of 686 nm and 763 nm, respectively, and fluorescence emission peaks of 1071 nm and 1066 nm, respectively. The photothermal effect of P-DPP can reach 52 °C, and the quantum yield reaches 1.5%, which was three times higher than that of nanotube fluorophores (quantum yield 0.4%). P-DPP is used for stable fluorescence imaging of blood vessels and photoacoustic imaging of nude mice, and successfully applied to phototherapy of nude mouse tumours.


Assuntos
Antineoplásicos/uso terapêutico , Nanopartículas/uso terapêutico , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Polímeros/uso terapêutico , Tiofenos/uso terapêutico , Animais , Antineoplásicos/síntese química , Antineoplásicos/efeitos da radiação , Antineoplásicos/toxicidade , Feminino , Corantes Fluorescentes , Células HeLa , Humanos , Hipertermia Induzida/métodos , Raios Infravermelhos , Fígado/diagnóstico por imagem , Camundongos Nus , Nanopartículas/efeitos da radiação , Nanopartículas/toxicidade , Técnicas Fotoacústicas/métodos , Fotoquimioterapia/métodos , Polímeros/síntese química , Polímeros/efeitos da radiação , Polímeros/toxicidade , Tiofenos/síntese química , Tiofenos/efeitos da radiação , Tiofenos/toxicidade , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Nat Commun ; 10(1): 3774, 2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31484927

RESUMO

Light-induced alteration of macromolecular information plays a central role in biology and is known to influence health, aging and Darwinian evolution. Here, we report that light can also trigger sequence variations in abiotic information-containing polymers. Sequence-coded poly(phosphodiester)s were synthesized using four phosphoramidite monomers containing either photo-sensitive or photo-inert substituents. These monomers allow different sequence manipulations. For instance, using two light-cleavable monomers containing o-nitrobenzyl ether and o-nitroveratryl ether motifs, photo-erasable digital polymers were prepared. These polymers can be decoded by tandem mass spectrometry but become unreadable after UVA exposure. The opposite behavior, i.e. photo-revealable sequences, was obtained with polymers made of two isobaric monomers containing light-cleavable o-nitrobenzyl ether and light-inert p-nitrobenzyl ether substituents. Furthermore, when the latter two monomers were used in conjunction with a third monomer bearing a light-inert OH group, site-directed photo-mutations were induced in synthetic polymers. This was used herein to change the meaning of binary sequences.


Assuntos
Técnicas de Química Sintética/métodos , Polímeros/efeitos da radiação , Raios Ultravioleta , Estrutura Molecular , Polímeros/síntese química , Espectrometria de Massas em Tandem
14.
Colloids Surf B Biointerfaces ; 183: 110423, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31437608

RESUMO

Photothermal therapy (PTT) is a promising method to kill bacteria because of the broad-spectrum of antibacterial activity and the ability of spatiotemporal regulation. In the previously reported systems, light induced high temperature (˜70 °C) was essential for effectively killing of bacteria, which, however, would also damage nearby nontarget cells or tissues. Here we report photothermal nanoparticles (NPs) for more targeting and killing bacteria at a relative low temperature. Polydopamine (PDA) was chosen to prepare NPs because of its excellent capability of photothermal conversion. Magainin I (MagI) which is an antimicrobial peptide was used to modify NPs' surface because it can specifically interact with bacteria. We demonstrate that MagI-PEG@PDA NPs effectively killed E. coli at a low temperature of ˜45 °C upon near-infrared (NIR) light irradiation. In contrast, the native PDA NPs under light irradiation or the MagI-PEG@PDA NPs themselves showed no bacteria killing ability. This work highlights the importance of close interaction between the target bacteria and the photothermal materials and may promote the practical clinical applications of the PTT.


Assuntos
Antibacterianos/efeitos da radiação , Peptídeos Catiônicos Antimicrobianos/farmacologia , Indóis/efeitos da radiação , Viabilidade Microbiana/efeitos dos fármacos , Nanopartículas/efeitos da radiação , Polímeros/efeitos da radiação , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Escherichia coli/efeitos dos fármacos , Escherichia coli/imunologia , Indóis/química , Raios Infravermelhos , Camundongos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos da radiação , Células NIH 3T3 , Nanopartículas/química , Nanopartículas/toxicidade , Polietilenoglicóis/química , Polímeros/química , Temperatura
16.
Cancer Radiother ; 23(5): 385-394, 2019 Sep.
Artigo em Francês | MEDLINE | ID: mdl-31300328

RESUMO

PURPOSE: The purpose of the study was to evaluate the outcomes of stereotactic radiation therapy for primary and secondary liver tumours in Jean-Perrin cancer centre (Clermont-Ferrand, France) in terms of efficacy and safety. MATERIALS AND METHODS: Between December 2013 and June 2016, 25 patients were included. Treatment was performed on a linear accelerator Novalis TX®. The prescription dose was 42 to 60Gy in three to five fractions. Local control at 1 year was evaluated with modified Response Evaluation Criteria in Solid Tumours (mRECIST) and RECIST criteria. Acute and late toxicity were evaluated with Common Terminology Criteria for Adverse Events (CTCAE) v4.0 criteria. RESULTS: Median follow-up was 10.5 months. Treatment tolerance was good with few side effects grade 3 or above, no acute toxicity and only one late toxicity. We have highlighted that hepatic artery haemorrhage was associated with the presence of a biliary prosthesis in contact with the artery (P=0.006) and in the irradiation field. There was no correlation with the dose delivered to the artery and hepatic artery haemorrhage. CONCLUSION: Stereotactic radiation therapy for liver tumours allows a good local control with few secondary effects. Caution should be exercised when treating patients with biliary prostheses in the vicinity of the target volume because there is a risk of haemorrhage of the hepatic artery in contact with the prosthesis.


Assuntos
Neoplasias Hepáticas/radioterapia , Hipofracionamento da Dose de Radiação , Lesões por Radiação/etiologia , Radiocirurgia/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/uso terapêutico , Carcinoma/radioterapia , Carcinoma/secundário , Carcinoma/terapia , Carcinoma Hepatocelular/radioterapia , Carcinoma Hepatocelular/terapia , Colangiocarcinoma/radioterapia , Colangiocarcinoma/terapia , Terapia Combinada , Intervalo Livre de Doença , Embolização Terapêutica , Feminino , Seguimentos , França/epidemiologia , Hemorragia/etiologia , Hepatectomia , Artéria Hepática/efeitos da radiação , Humanos , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/terapia , Masculino , Pessoa de Meia-Idade , Polietileno/efeitos da radiação , Polímeros/efeitos da radiação , Lesões por Radiação/epidemiologia , Planejamento da Radioterapia Assistida por Computador , Estudos Retrospectivos , Stents
17.
Nat Commun ; 10(1): 3089, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31300649

RESUMO

Dual-emissive systems showing color-specific photoswitching are promising in bioimaging and super-resolution microscopy. However, their switching efficiency has been limited because a delicate manipulation of all the energy transfer crosstalks in the systems is unfeasible. Here, we report a perfect color-specific photoswitching, which is rationally designed by combining the complete off-to-on fluorescence switching capability of a fluorescent photochromic diarylethene and the frustrated energy transfer to the other fluorescent dye based on the excited-state intramolecular proton transfer (ESIPT) process. Upon alternation of UV and visible light irradiations, the system achieves 100% switching on/off of blue emission from the diarylethene while orange emission from the ESIPT dye is unchanged in the polymer film. By fabricating this system into biocompatible polymer nanoparticles, we demonstrate microscopic imaging of RAW264.7 macrophage cells with reversible blue-color specific fluorescence switching that enables super-resolution imaging with a resolution of 70 nm.


Assuntos
Transferência de Energia/efeitos da radiação , Corantes Fluorescentes/química , Microscopia Intravital/métodos , Imagem Molecular/métodos , Nanopartículas/química , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/efeitos da radiação , Cor , Fluorescência , Corantes Fluorescentes/efeitos da radiação , Luz , Camundongos , Microscopia Eletrônica de Transmissão/métodos , Microscopia de Fluorescência/métodos , Nanopartículas/efeitos da radiação , Polímeros/química , Polímeros/efeitos da radiação , Células RAW 264.7
18.
ACS Appl Mater Interfaces ; 11(30): 27353-27357, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31287645

RESUMO

Electronic textiles (e-textiles) are being developed because of their potential applications in wearable and flexible electronics. However, complex procedures and chemical agents are required to synthesize carbon-based e-textiles. Pyroprotein-based e-textiles, obtained by the pyrolysis of silk proteins, consume large amounts of time and energy due to the high-temperature process (from 800 to 2800 °C). In this study, we report a novel method of fabricating pyroprotein-based electronic yarns (e-yarns) using microwave irradiation. Microwaves were applied to pyroprotein treated at 650 °C to remove numerous heteroatoms in a short time without the high-temperature process and chemical agents. The structural modulation was confirmed by Raman spectroscopy and X-ray photoelectron spectroscopy. We found a reduction in heteroatoms and enlargement of the carbon region. The temperature-dependent resistance was well explained by the fluctuation-induced tunneling model, which also showed structural modification. The electrical conductivity of the fabricated e-yarns was comparable to that of pyroprotein-based e-textiles heat-treated at 1000 °C (order of 102 S/cm) and showed electrical stability under bending.


Assuntos
Eletrônica , Proteínas/efeitos da radiação , Seda/efeitos da radiação , Têxteis , Condutividade Elétrica , Micro-Ondas , Polímeros/química , Polímeros/efeitos da radiação , Proteínas/química , Pirólise , Seda/química , Dispositivos Eletrônicos Vestíveis
19.
Anal Chem ; 91(15): 10188-10196, 2019 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-31283183

RESUMO

Reversible protein phosphorylation on serine, threonine, and tyrosine residues is essential for fast, specific, and accurate signal transduction in cells. Up to now, the identification and quantification of phosphorylated amino acids, peptides, and proteins continue to be one of the significant challenges in contemporary bioanalytical research. In this paper, a series of surface grafted monoliths in the capillary format targeting phosphorylated serine has been prepared by first synthesizing a monolithic core substrate material based on trimethylolpropane trimethacrylate, onto which a thin surface-imprinted layer was established by oriented photografting of a variety of mono- and bis-imidazolium host monomers at subzero temperature, using six different continuous or pulsed UV light sources. The imprinted monolith capillaries were evaluated in a capillary liquid chromatographic system connected to a mass spectrometer in order to test the specific retention of phosphorylated peptides. Site-specific recognition selectivity and specificity for phosphorylated serine was demonstrated when separating amino acids and peptides, proving that the optimized materials could be used as novel trapping media in affinity-based phosphoproteomic analysis.


Assuntos
Angiotensina II/metabolismo , Cromatografia de Afinidade/métodos , Imidazóis/química , Impressão Molecular/métodos , Fosfopeptídeos/isolamento & purificação , Polímeros/química , Raios Ultravioleta , Angiotensina II/química , Humanos , Fosfopeptídeos/química , Fosforilação , Polímeros/efeitos da radiação
20.
Mikrochim Acta ; 186(7): 430, 2019 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-31187249

RESUMO

A photoelectrochemical (PEC) method is described for aptamer-based detection of ofloxacin (OFL). It is making use of a TiO2 nanotube array (NTA) that is sensitized with a structure composed of polydopamine and silver sulfide nanoparticles. The NTA were prepared by a two-step synthetic method. First, the TiO2 nanotube electrode was covered with Ag2S nanoparticles via successive ionic layer adsorption and reaction strategy. Next, they were coated with a thin film of polydopamine (PDA) by in-situ polymerization. The inorganic/organic nanocomposites exhibit distinctly enhanced visible-light PEC activity. This was exploited to fabricate a PEC aptasensor. The PDA film serves as both the sensitizer for charge separation and as a support to bind the aptamer against OFL. The aptasensor undergoes a decrease in photocurrent due to the formation of the aptamer-OFL complex. Under the optimized conditions and at a typical working potential of 0 V (vs. Hg/Hg2Cl2), the NTA has a linear response in the 5.0 pM to 100 nM OFL concentration range and a 0.75 pM detection limit (at S/N = 3). The aptasensor was successfully applied to the determination of OFL in spiked milk samples. Graphical abstract Schematic illustration for the preparation and mechanism of the photoelectrochemical aptasensor for ofloxacin. TiO2 NTs: TiO2 nanotube arrays; PDA: polydopamine; MCH: 6-mercapto-1-hexanol; OFL: ofloxacin; PEC: photoelectrochemistry; CB: conduction band; VB: valence band; LUMO: the lowest unoccupied molecular orbital; HOMO: the highest occupied molecular orbital; AA: ascorbic acid.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Nanopartículas Metálicas/química , Nanocompostos/química , Nanotubos/química , Ofloxacino/análise , Animais , Aptâmeros de Nucleotídeos/metabolismo , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Contaminação de Alimentos/análise , Indóis/química , Indóis/efeitos da radiação , Luz , Limite de Detecção , Leite/química , Nanotubos/efeitos da radiação , Ofloxacino/metabolismo , Polímeros/química , Polímeros/efeitos da radiação , Reprodutibilidade dos Testes , Compostos de Prata/química , Titânio/química
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