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1.
BMC Oral Health ; 23(1): 928, 2023 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-38007495

RESUMO

BACKGROUND: Trans- inferior alveolar nerve (IAN) implantation technique was wildly used while the potential appropriate angle range in which the residual alveolar bone can bear the stress without absorption are currently unclear. This study aimed to evaluate the stress distribution pattern of the interface between bone and implant by finite element analysis (FEA) to determine the appropriate range of the implant tilt angle. METHODS: Cone beam computed tomography (CBCT) images of 120 patients with missing mandibular second molars and vertical bone height < 9 mm in the edentulous area were selected. The distances from the mandibular nerve canal to the buccal cortex, the lingual cortex and the alveolar ridge crest were measured by using a combination of software. The angular ranges of the buccal-lingual inclination of simulated trans-IAN implants were measured and three-dimensional finite element models were constructed in the mandibular second molar area according to the differences of the inclination angles. A vertical load (200N) was then applied to analyze the biomechanical conditions of the implant-bone interface during median occlusion. RESULTS: The distance at the second molar from the nerve canal to the buccal cortex, lingual cortex and alveolar crest were 6.861 ± 1.194 mm, 2.843 ± 0.933 mm and 7.944 ± 0.77 mm. Trans-IAN implantation was feasible in 73.33% of patients. The minimum angle and maximum angles of the buccal-lingual inclination of the simulated implant were 19.135 ± 6.721° and 39.282 ± 6.581°. When a vertical static load of 200N was applied, the tensile stress in cortical bone gradually increased with the increase of the implant tilt angle. When the inclination angle reached 30°, the tensile stress (105.9 MPa) exceeded the yield strength (104 MPa) of cortical bone. Compared with the conventional implants, the stress peak value of the vertical ultra-short implant in cortical bone was greater than the stress peak value of the conventional implants at 10°(79.81 MPa) and 20°(82.83 MPa) and was smaller than the stress of the implant at 30°(105.9 MPa) and 40°(107.8 MPa). Therefore, when the bone mass allows, conventional-length implants should be selected whenever possible, and an operative range of the trans-IAN implantation in the mandibular second molar could be retained with an inclination angle of < 30°. CONCLUSIONS: The mandibular nerve canal at the mandibular second molar was obviously biased to the lingual side, which ensured sufficient bone mass at the buccal side. In most patients with severe mandibular atrophy, it was possible to maintain a safe distance from the nerve canal with conventional-length implants via the trans-IAN implantation technique.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Implantes Dentários , Humanos , Análise de Elementos Finitos , Tomografia Computadorizada de Feixe Cônico/métodos , Processo Alveolar/diagnóstico por imagem , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Dente Molar/diagnóstico por imagem , Nervo Mandibular
2.
Mikrochim Acta ; 188(3): 103, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33646401

RESUMO

Molybdenum disulfide (MoS2) surface functionalization was performed with a catechol-containing polymer sodium alginate (SA) and dopamine (DA) through simultaneous MoS2 exfoliation and self-polymerization of DA. The MoS2/SA-PDA nanocomposite was characterized using spectroscopic, microscopic, and electroanalytical techniques to evaluate its electrocatalytic performance. The electrocatalytic behavior of the MoS2/SA-PDA nanocomposite modified electrode for the detection of acebutolol (ACE), a cardio-selective ß-blocker drug was explored  through cyclic voltammetric and differential pulse voltammetric techniques. The influence of scan rate, concentration, and pH value on the oxidation peak current of ACE was investigated  to optimize the deducting condition. The electrochemical activity of the MoS2/SA-PDA nanocomposite electrode was attributed to the existence of reactive functional groups being contributed from SA, PDA, and MoS2 exhibiting a synergic effect. The MoS2/SA-PDA nanocomposite modified electrode exhibits admirable electrocatalytic activity with a wide linear response range (0.009 to 520 µM), low detection limit (5 nM), and high sensitivity (0.354 µA µM-1 cm-2) also in the presence of similar (potentially interfering) compounds. The fabricated MoS2/SA-PDA nanocomposite modified electrode can be useful for the detection of ACE in pharmaceutical analysis.


Assuntos
Acebutolol/análise , Antagonistas de Receptores Adrenérgicos beta 1/análise , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Nanocompostos/química , Acebutolol/sangue , Acebutolol/química , Acebutolol/urina , Antagonistas de Receptores Adrenérgicos beta 1/sangue , Antagonistas de Receptores Adrenérgicos beta 1/química , Antagonistas de Receptores Adrenérgicos beta 1/urina , Alginatos/química , Técnicas Biossensoriais/métodos , Dissulfetos/química , Técnicas Eletroquímicas/métodos , Eletrodos , Humanos , Indóis/química , Limite de Detecção , Molibdênio/química , Oxirredução , Polímeros/química , Reprodutibilidade dos Testes
3.
Int J Mol Sci ; 22(7)2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33807391

RESUMO

Salivary levels of interleukin-8 (IL-8) are elevated in patients with periodontitis. Caffeic acid phenethyl ester (CAPE) improves the periodontal status in subjects. However, whether CAPE can reduce IL-8 expression is unclear. We collected saliva to determine proinflammatory cytokine levels and used subgingival calculus and surrounding tissues from patients with periodontitis for oral microbiota analysis via 16s ribosomal RNA gene sequencing. THP-1 cells were stimulated with sterile-filtered saliva from patients, and target gene/protein expression was assessed. IL-8 mRNA expression was analyzed in saliva-stimulated THP-1 cells treated with CAPE and the heme oxygenase-1 (HO-1) inhibitor tin-protoporphyrin (SnPP). In 72 symptomatic individuals, IL-8 was correlated with periodontal inflammation (bleeding on probing, r = 0.45; p < 0.001) and disease severity (bleeding on probing, r = 0.45; p < 0.001) but not with the four oral microbiota species tested. Reduced salivary IL-8 secretion was correlated with effective periodontitis treatment (r = 0.37, p = 0.0013). In THP-1 cells, saliva treatment induced high IL-8 expression and IKK2 and nuclear factor-κB (NF-κB) phosphorylation. However, the IKK inhibitor BMS-345541, NF-κB inhibitor BAY 11-7082, and CAPE attenuated saliva-induced IL-8 expression. CAPE induced HO-1 expression and inhibited IKK2, IκBα, and NF-κB phosphorylation. Blocking HO-1 decreased the anti-inflammatory activity of CAPE. The targeted suppression of IL-8 production using CAPE reduces inflammation and periodontitis.


Assuntos
Ácidos Cafeicos/farmacologia , Interleucina-8/metabolismo , Periodontite/tratamento farmacológico , Álcool Feniletílico/análogos & derivados , Anti-Inflamatórios/farmacologia , Ácidos Cafeicos/metabolismo , Citocinas/metabolismo , Heme Oxigenase-1/metabolismo , Humanos , Proteínas I-kappa B/metabolismo , Inflamação/tratamento farmacológico , Interleucina-8/antagonistas & inibidores , Lipopolissacarídeos/metabolismo , Inibidor de NF-kappaB alfa/metabolismo , NF-kappa B/metabolismo , Periodontite/imunologia , Periodontite/metabolismo , Álcool Feniletílico/metabolismo , Álcool Feniletílico/farmacologia , Fosforilação/efeitos dos fármacos , Saliva/química , Células THP-1
4.
Anal Chem ; 92(13): 8965-8973, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32436691

RESUMO

In this work, a graphene oxide (GRO)-based temperature-sensitive smart catalytic support material was developed by tethering biodegradable and hydrophilic poly(N-vinylcaprolactam) (PVCL) on a GRO (i.e., GRO-PVCL) surface. GRO-PVCL-supported palladium catalyst (i.e., Pd/GRO-PVCL) was then prepared for tizanidine (TZN) electroreduction. The impact of a temperature-sensitive smart surface on the electrochemical and electrocatalytic properties was examined. Moreover, when the large surface area, excellent electron transfer, and electrochemical catalysis abilities of GRO were combined with the responsive characteristics of PVCL, temperature-triggered reversible electrocatalysis of TZN with enhanced sensitivity has been proved. Results designated that GRO-PVCL exposed the hydrophilic surface at 20 °C, resulting in Pd NPs highly dispersed on the GRO-PVCL surface. Subsequently, the wettability of the Pd catalyst surface arbitrarily adapted to hydrophobicity at 40 °C, which highly enhanced the TZN reduction on the catalyst in electrochemical detection. The synergistic effect amid Pd and GRO-PVCL on Pd/GRO-PVCL improved the electrocatalytic activity of TZN. The detection of TZN with the Pd/GRO-PVCL modified electrode ranged from 0.02 to 276 µM with a low detection limit of 0.0015 µM at 40 °C. The Pd/GRO-PVCL modified electrode also possesses excellent stability, reproducibility, and anti-interference ability. Lastly, the modified electrode attained good recovery results in human urine and human plasma samples for the determination of TZN and also pharmacokinetics study in rat plasma.


Assuntos
Clonidina/análogos & derivados , Técnicas Eletroquímicas/métodos , Grafite/química , Paládio/química , Caprolactama/análogos & derivados , Caprolactama/química , Catálise , Clonidina/análise , Clonidina/química , Eletrodos , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção , Nanocompostos/química , Polímeros/química , Reprodutibilidade dos Testes , Propriedades de Superfície , Temperatura
5.
Macromol Rapid Commun ; 41(11): e2000088, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32329178

RESUMO

Surface properties are essential for substrates exhibiting high sensitivity in surface-enhanced Raman scattering (SERS) applications. In this work, novel SERS hybrid substrates using polystyrene-block-poly(methyl methacrylate) and anodic aluminum oxide templates is presented. The hybrid substrates not only possess hierarchical porous nanostructures but also exhibit superhydrophilic surface properties with the water contact angle ≈0°. Such surfaces play an important role in providing uniform enhanced intensities over large areas (relative standard deviation ≈10%); moreover, these substrates are found to be highly sensitive (limit of detection ≈10-12 m for rhodamine 6G (R6G)). The results show that the hybrid SERS substrates can achieve the simultaneous detection of multicomponent mixtures of different target molecules, such as R6G, crystal violet, and methylene blue. Furthermore, the bending experiments show that about 70% of the SERS intensities are maintained after bending from ≈30° to 150°.


Assuntos
Óxido de Alumínio/química , Polímeros/química , Rodaminas/análise , Molhabilidade , Eletrodos , Tamanho da Partícula , Análise Espectral Raman , Propriedades de Superfície
6.
Macromol Rapid Commun ; 41(8): e2000035, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32125049

RESUMO

1D polymer nanomaterials have attracted significant interest in recent years because of their unique properties and promising applications in various fields. It is, however, still a challenge to fabricate polymer nanoarrays with desired sizes and controlled morphologies. Here, an unprecedented approach, the laser-assisted nanowetting (LAN) method, to selectively fabricate polymer nanoarrays is presented. Polystyrene (PS) is blended with gold nanorods (AuNRs), which are used to absorb the energy from the laser. After the blend films are brought in contact with AAO templates, the AuNRs at regions shone by the laser beams absorb the energy and heat the surrounding polymer chains, resulting in the formation of PS/AuNRs arrays in selected areas. This work paves a new research direction for developing template-based polymer nanomaterials.


Assuntos
Óxido de Alumínio/química , Ouro/química , Lasers , Nanoestruturas/química , Poliestirenos/química , Eletrodos , Tamanho da Partícula , Propriedades de Superfície , Molhabilidade
7.
Mikrochim Acta ; 187(10): 580, 2020 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-32979097

RESUMO

A 3D flexible domestic waste styrofoam is reported as a surface enhanced Raman scattering (SERS) substrate loaded with BiOCl-BiOBr@Pt/Au semiconductor-plasmonic composites. The hydrothermally prepared BiOCl-BiOBr nanocomposite is thoroughly characterized for its crystal structure using X-Ray diffraction, morphology through scanning electron microscopy, and electronic states of the elements using X-ray photoelectron spectroscopy. The alpha cypermethrin (ACM) is chosen as a model pesticide analyte for SERS investigation. The BiOCl-BiOBr@Pt/Au loaded foam substrate exhibited a high enhancement factor (106) and low limit of detection (10-10 M) upon SERS investigation. The unique architecture of the semiconductor-plasmonic composite enables an efficient charge transfer capability and plasmonic hotspots which aids in the enhancement of target analytes. In order to better demonstrate the versatility towards other pesticides, SERS detection of glyphosate and paraquat pesticides are also performed using the fabricated SERS substrate. The stability of the substrate has been investigated in detail for 30 days and the substrate was highly stable. The BiOCl-BiOBr@Pt/Au-based foam substrate also performed well in rapid real-time sensing of alpha cypermethrin on the kiwi fruit exocarp at lower level concentrations. Graphical abstract.


Assuntos
Nanopartículas Metálicas/química , Praguicidas/química , Poliestirenos/química , Humanos , Prata/química
8.
Mikrochim Acta ; 186(9): 651, 2019 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-31463587

RESUMO

Lanthanum oxide nanomaterials were decorated with carbon black (CB) and grafted with a poly(acrylic acid) nanogel to obtain a composite material (CB-g-PAA/La2O3) for simultaneous determination of acetaminophen (AMP), naproxen (NPX), and theophylline (TPH). The nanogel was synthesized by in-situ free radical polymerization. The composite was dropped onto a glassy carbon electrode (GCE), and the modified GCE displays robust electrocatalytic activity towards AMP, NPX, and TPH, with voltammetric signals that are enhanced compared to a bare GCE. Features of merit for AMP, NPX, and TPH, respectively, include (a) peak potentials of 0.42, 0.85 and 0.12 V (vs. Ag/AgCl), (b) linear ranges from 0.05-887, 0.05-884, and 0.02-888 µM, and (c) detection limits of 20, 35, and 15 nM. The practical applicability of the CB-g-PAA/La2O3/GCE was illustrated by analyzing serum and urine samples. Graphical abstract Schematic presentation of simultaneous electrochemical sensing of acetaminophen (AMP), naproxen (NPX), and theophylline (TPH) in real sample analysis using poly(acrylic acid) nanogel covalently grafted onto a carbon black/La2O3 composite (CB-g-PAA/La2O3/GCE).


Assuntos
Acetaminofen/análise , Resinas Acrílicas/química , Lantânio/química , Nanogéis/química , Naproxeno/análise , Óxidos/química , Fuligem/química , Teofilina/análise , Acetaminofen/sangue , Acetaminofen/urina , Eletroquímica , Eletrodos , Humanos , Modelos Moleculares , Conformação Molecular , Naproxeno/sangue , Naproxeno/urina , Polimerização , Teofilina/sangue , Teofilina/urina
9.
Phys Chem Chem Phys ; 18(24): 16466-75, 2016 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-27265120

RESUMO

A one-pot synthesis method for the fabrication of biomass-derived activated carbon-zinc oxide (ZAC) nanocomposites using sugarcane bagasse as a carbon precursor and ZnCl2 as an activating agent is reported. For the first time, we used ZnCl2 as not only an activating agent and also for the synthesis of ZnO nanoparticles on the AC surface. ZAC materials with varying ZnO loading were prepared and characterized by a variety of analytical and spectroscopic techniques such as FE-SEM, FE-TEM, XRD, EA, XPS, and Raman spectroscopy. ZAC-modified glassy carbon electrodes (GCEs) were found to exhibit remarkable electrochemical properties for simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) as well as hazardous pollutants such as hydrogen peroxide (H2O2) and hydrazine (N2H4) with desirable sensitivity, selectivity, and detection limits. Moreover, ZAC-modified stainless steel electrodes also showed superior performances for supercapacitor applications. The ZAC nanocomposites, which may be mass produced by the reported facile direct route from sugarcane bagasse, are not only eco-friendly but also cost-effective, and thus, are suitable as a practical platform for bio-sensing and energy storage applications.


Assuntos
Técnicas Biossensoriais , Carbono/química , Fontes de Energia Elétrica , Nanocompostos/química , Óxido de Zinco/química , Ácido Ascórbico/análise , Celulose/química , Cloretos/química , Dopamina/análise , Capacitância Elétrica , Eletrodos , Química Verde , Hidrazinas/análise , Peróxido de Hidrogênio/análise , Limite de Detecção , Tamanho da Partícula , Porosidade , Saccharum , Ácido Úrico/análise , Compostos de Zinco/química , Óxido de Zinco/síntese química
10.
Med Sci Monit ; 21: 1617-24, 2015 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-26038188

RESUMO

BACKGROUND: Interleukin-1ß (IL-1ß) is an important inflammatory cytokine. The associations between IL-1ß gene -511C>T/+3954C>T polymorphisms and aggressive periodontitis (AgP) susceptibility have been conflicting. We therefore conducted a meta-analysis to investigate the association of IL-1ß genetic polymorphisms with susceptibility to AgP. MATERIAL AND METHODS: PubMed and Embase electronic databases were searched for relevant studies. Odds ratios (ORs) with 95% confidence interval (CIs) were used to assess the association between IL-1ß polymorphisms and AgP risk. Heterogeneity, publication bias, and sensitivity analysis were performed to guarantee the statistical power. RESULTS: Twenty published studies involving 965 patients and 1234 control subjects were included. No significant association between IL-1ß polymorphisms and AgP was found. For -511C>T (T vs. C: OR=0.966, 95%CI=0.696-1.341, P=0.869; CT vs. CC: OR=0.936, 95%CI=0.761-1.151; TT vs. CC: OR=0.892, 95%CI=0.464-1.715, P=0.719; CT+TT vs. CC: OR=1.026, 95%CI=0.795-1.323; TT vs. CC+CT: OR=0.864, 95%CI=0.436-1.713). For +3954C>T (T vs. C: OR=1.069, 95%CI=0.901-1.268; CT vs. CC: OR=0.921, 95%CI=0.699-1.212; TT vs. CC: OR=1.064, 95%CI=0.747-1.515; CT+TT vs. CC: OR=0.990, 95%CI=0.764-1.283; TT vs. CC+CT: OR=1.229, 95%CI=0.919-1.643). Subgroup analyses were conducted with HWE, ethnicity, and study design, and no significant association was detected. CONCLUSIONS: These results demonstrate that IL-1ß -511C>T and +3954C>T polymorphisms are not the risk factors for developing AgP.


Assuntos
Periodontite Agressiva/genética , Predisposição Genética para Doença/genética , Interleucina-1beta/genética , Polimorfismo de Nucleotídeo Único/genética , Estudos de Associação Genética , Humanos , Razão de Chances , PubMed
11.
J Nanosci Nanotechnol ; 15(12): 9777-87, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26682412

RESUMO

In this work, we have reported the preparation and optimization of paclitaxel (PTX) and temozolomide (TMZ) loaded monomethoxy (polyethylene glycol)-poly(D, L-lactide-co-glycolide) (mPEG-PLGA) nanocomposite which is a thermo-sensitive gel delivery system to glioblastoma. We utilized the orthogonal design and homogeneous design for the optimal drug-loaded nanoparticles (NPs) and composite gel prescription, respectively. The physicochemical characteristics of NPs and rheological properties of the gel were analyzed. Then the in vitro release of the gel was determined with a membrane-less diffusion system. Finally, the cytotoxic and apoptosis-inducing effects of the gel on the human malignant glioblastoma cell line U87 and C6 rat glioblastoma cell line were evaluated by MTT and flow cytometry apoptosis assay, respectively. The transmission electron microscopy (TEM) analysis revealed the optimized NPs with a relatively uniform diameter and distribution. The homogeneous design and rheological determination showed that the optimized gel prescription was 250 mg/mL Pluronic F127 (F127), 0.5% hydroxy propyl methylcellulose (HPMC-100M), 0.5% Pluronic F68 (F68), 0.5% sodium alginate (SA) and suitable NPs, which possessed the appropriate gelation behaviors: gelation temperature 28.01 degrees C, gelation time 127.1 s and corrosion speed 0.1892 g/cm2 x hr; and rheological properties: suitable elasticity modulus, viscosity modulus and low phase angle. The in vitro results suggested that the PTX and TMZ were sustainedly released from nanoparticles or the composite gel, and the release and elimination time greatly prolonged; and the composite gel possessed much higher growth-inhibiting effect and apoptosis-inducing rate in U87 and C6 cells than other formulations. These findings demonstrated that the optimal gel was a promising delivery system for the interstitial chemotherapy to glioblastoma.


Assuntos
Dacarbazina/análogos & derivados , Portadores de Fármacos/química , Glioblastoma/tratamento farmacológico , Nanocompostos/química , Paclitaxel/farmacologia , Animais , Linhagem Celular Tumoral , Dacarbazina/farmacologia , Humanos , Poliésteres/química , Polietilenoglicóis/química , Ratos , Temozolomida
12.
Tissue Eng Regen Med ; 20(3): 473-488, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36920677

RESUMO

BACKGROUND: Ever-growing tissue regeneration causes pressing need for large population of stem cells. However, extensive cell expansion eventually leads to impaired regenerative potentials. In this study, chromobox protein homolog 7 (CBX7) was overexpressed to rejuvenate late passage dental pulp stem cells (DPSCs-P9). METHODS: The recruitment of copper ions (Cu2+)-activated hypoxia-inducible factor-1α (HIF-1α) to the CBX7 gene promoter was confirmed by chromatin immunoprecipitation assay. Functions subsequent to Cu2+-induced or recombinant overexpression of CBX7 on proliferation, multipotency, odontoblastic differentiation and angiogenesis were investigated in vitro, while murine subcutaneous transplantation model was used to further detect the effects of Cu2+-induced CBX7 overexpression in vivo. RESULTS: Our data displayed that CBX7 overexpression maintain proliferation and multipotency of DPSCs-P9 almost as strong as those of DPSCs-P3. Both gene level of odontoblast-lineage markers and calcium precipitation were nearly the same between CBX7 overexpressed DPSCs-P9 and normal DPSCs-P3. Moreover, we also found upregulated expression of vascular endothelial growth factor in DPSCs-P9 with CBX7 overexpression, which increased the number of capillary-like structures and migrating co-cultured human umbilical vein endothelial cells as well. These findings indicate CBX7 as an effective factor to rejuvenate late passage stem cells insusceptible to cell expansion. Cu2+ has been proved to achieve CBX7 overexpression in DPSCs through the initiation of HIF-1α-CBX7 cascade. Under Cu2+ stimulation since P3, DPSCs-P9 exhibited ameliorated regenerative potential both in vitro and in vivo. CONCLUSION: Long-term stimulation of Cu2+ to overexpress CBX7 could be a new strategy to manufacture large population of self-renewing stem cells.


Assuntos
Polpa Dentária , Fator A de Crescimento do Endotélio Vascular , Humanos , Camundongos , Animais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Polpa Dentária/metabolismo , Células-Tronco , Diferenciação Celular , Células Endoteliais da Veia Umbilical Humana/metabolismo , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Complexo Repressor Polycomb 1/farmacologia
13.
Analyst ; 137(1): 186-94, 2012 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-22046584

RESUMO

A simple method to immobilize poly(neutral red) (PNR) and flavin adenine dinucleotide (FAD) hybrid film (PNR/FAD) by cyclic voltammetry is proposed. The PNR/FAD hybrid film can be easily prepared on an electrode surface involving electropolymerization of neutral red (NR) monomers and the electrostatic interaction between the positively charged PNR and the negatively charged FAD. It exhibits electroactive, stable, surface-confined, pH-dependent, nano-sized, and compatible properties. It provides good electrocatalytic properties to various species. It shows a sensitivity of 5.4 µA mM(-1) cm(-2) and 21.5 µA mM(-1) cm(-2) for hydrogen peroxide (H(2)O(2)) and nicotinamide adenine dinucleotide (NADH) with the linear range of 0.1 µM-39 mM and 5 × 10(-5) to 2.5 × 10(-4) M, respectively. It shows another linear range of 48.8-355.5 mM with the sensitivity of 12.3 µA mM(-1) cm(-2) for H(2)O(2). In particular, the PNR/FAD hybrid film has potential to replace some hemoproteins to be a cathode of biofuel cells and provide the biosensing system for glucose and ethanol.


Assuntos
Técnicas Biossensoriais/métodos , Flavina-Adenina Dinucleotídeo/química , Peróxido de Hidrogênio/análise , NAD/análise , Vermelho Neutro/química , Polímeros/química , Álcoois/análise , Álcoois/química , Sítios de Ligação , Técnicas Biossensoriais/instrumentação , Catálise , Corantes/química , Corantes/metabolismo , Eletroquímica , Eletrodos , Flavina-Adenina Dinucleotídeo/metabolismo , Glucose/análise , Glucose/química , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , NAD/química , Nanocompostos/química , Vermelho Neutro/metabolismo , Oxirredução , Polímeros/metabolismo , Sensibilidade e Especificidade
14.
BMC Cardiovasc Disord ; 12: 115, 2012 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-23206536

RESUMO

BACKGROUND: In a previous in vitro study, we confirmed that small-caliber nanofibrous polyurethane (PU) vascular grafts have favorable mechanical properties and biocompatibility. In the present study, we examined the in vivo biocompatibility and stability of these grafts. METHODS: Forty-eight adult male beagle dogs were randomly divided into two groups receiving, respectively, polyurethane (PU) or polytetrafluoroethylene (PTFE) grafts (n = 24 animals / group). Each group was studied at 4, 8, 12, and 24 weeks after graft implantation. Blood flow was analyzed by color Doppler ultrasound and computed tomography angiography. Patency rates were judged by animal survival rates. Coverage with endothelial and smooth muscle cells was characterized by hematoxylin-eosin and immunohistological staining, and scanning electron microscopy (SEM). RESULTS: Patency rates were significantly higher in the PU group (p = 0.02 vs. PTFE group). During the first 8 weeks, endothelial cells gradually formed a continuous layer on the internal surface of PU grafts, whereas coverage of PTFE graft by endothelial cells was inhomogeneous. After 12 weeks, neointimal thickness remained constant in the PU group, while PTFE group showed neointimal hyperplasia. At 24 weeks, some anastomotic sites of PTFE grafts became stenotic (p = 0.013 vs. PU group). Immunohistological staining revealed a continuous coverage by endothelial cells and an orderly arrangement of smooth muscle cells on PU grafts. Further, SEM showed smooth internal surfaces in PU grafts without thrombus or obvious neointimal hyperplasia. CONCLUSIONS: Small-caliber nanofibrous PU vascular grafts facilitate the endothelialization process, prevent excessive neointimal hyperplasia, and improve patency rates.


Assuntos
Prótese Vascular , Nanofibras , Poliuretanos , Animais , Implante de Prótese Vascular , Cães , Endotélio Vascular/fisiologia , Masculino , Neointima/prevenção & controle , Politetrafluoretileno , Grau de Desobstrução Vascular
15.
J Nanosci Nanotechnol ; 12(6): 4467-71, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22905486

RESUMO

The main purpose of this study was to evaluate the targeting effect of cyclic arginine-glycine-aspartic peptide (cRGD)-modified monomethoxy (polyethylene glycol)-poly (D, L-lactide-co-glycolide)-poly (L-lysine) nanoparticles (mPEG-PLGA-PLL-cRGD NPs) for gastric cancer SGC-7901 cells. We prepared the 5-Fulorouracil (5Fu)-loaded mPEG-PLGA-PLL-cRGD (5Fu/mPEG-PLGA-PLL-cRGD) NPs that had an average particle size of 180 nm and a zeta potential 2.77 mV. The results of cytotoxicity demonstrated the mPEG-PLGA-PLL-cRGD NPs showed the ignorable cytotoxicity and the 5Fu/mPEG-PLGA-PLL-cRGD NPs could significantly enhance the cytotoxicity of 5Fu. In vitro drug release experiments showed that the release of drug was effectively prolonged and sustained. The results of confocal laser scanning microscope (CLSM) and flow cytometer analysis demonstrated that the fluorescence intensity of the SGC-7901 gastric cancer cells treated with Rb/mPEG-PLGA-PLL-cRGD NPs was significantly higher than that treated with Rb, this suggested that Rb/mPEG-PLGA-PLL-cRGD NPs could effectively be internalized by SGC-7901 gastric cancer cells. In summary, the above experimental results illustrate that mPEG-PLGA-PLL-cRGD NPs have great potential to be used as an effective delivery carriers.


Assuntos
Fluoruracila/administração & dosagem , Terapia de Alvo Molecular/métodos , Nanocápsulas/química , Poliésteres/química , Polietilenoglicóis/química , Polilisina/análogos & derivados , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Linhagem Celular Tumoral , Difusão , Fluoruracila/química , Humanos , Teste de Materiais , Nanocápsulas/administração & dosagem , Peptídeos Cíclicos , Polilisina/química , Resultado do Tratamento
16.
Zhonghua Yi Xue Za Zhi ; 92(15): 1054-7, 2012 Apr 17.
Artigo em Zh | MEDLINE | ID: mdl-22781649

RESUMO

OBJECTIVE: To fabricate porous biodegradable tissue engineered vein containing valve scaffolds. METHODS: Based on the self-made cast, the tissue engineered vein containing valve scaffolds was fabricated by injection molding plus thermally induced phase separation. Poly (lactic-co-glycolic acid) (PLGA, LA/GA mole ratio 75:25) was used as matrices. Morphological structures and biocompatibility of scaffolds were tested. Cell seeding on scaffold was performed and the mechanic characteristics of cellular constructs evaluated. RESULTS: The scaffold had an inner diameter of 9 mm with a wall thickness of 0.9 mm and the thickness of valves was (0.32 ± 0.04) mm. Scanning electron microscopic (SEM) micrographs showed regular ladder-like porous structures and the average pore size and porosity of scaffolds were 10 - 20 µm and 90%. The PLGA scaffolds were biocompatible. The cellular constructs were tested in vitro, and the valve leaflets were functionally capable of opening and closing when stimulated. CONCLUSION: Based on the self-made cast, the tissue engineered vein containing valve scaffolds can be fabricated by injection molding plus thermally induced phase separation. Further researches are warranted.


Assuntos
Engenharia Tecidual , Alicerces Teciduais , Válvulas Venosas , Materiais Biocompatíveis , Ácido Láctico , Teste de Materiais , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
17.
Chemosphere ; 291(Pt 3): 132977, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34801570

RESUMO

Pharmaceutical wastes, acetaminophen (AP) widely used in medical fields, is often discharged into water, causing harm to human health. Hence, there is an urgent need to effectively remove AP from wastewater systems. In this paper, polypyrrole (PPy) composite with MoO3 has been synthesized via an in-situ polymerization method. The as-prepared materials were thoroughly characterized by XRD, FT-IR, UV-DRS, SEM, TEM and mapping techniques. The as-prepared MoO3@PPy composite was utilized to removal of AP via photocatalytic degradation and electrochemical determination. Under optimized composite, MoO3@PPy (2) showed an excellent photocatalytic degradation and electrochemical determination of AP compared to pure MoO3 and all other composites. The higher catalytic activity was ascribed to the effective interfacial charges transfer, reduce the recombination and enhance the active surface area of electrode via a synergistic effect. The photocatalytic degradation mechanism, rate and kinetic of the reaction were investigated and discussed. The major active degradation species and an effective charge transfer properties were confirmed by trapping experiments and photocurrent spectra. In addition, the MoO3@PPy (2) modified GCE exhibit the AP determination activity by DPV with a linear range of 0.05-546 µM. The limit of detection and sensitivity of electrode were 0.0007 µM and 0.242 µM-1 cm-2 respectively. Moreover, the proposed electrode showed good selectivity, stability and reproducibility. This method was useful for the determination of AP in real samples.


Assuntos
Polímeros , Pirróis , Acetaminofen , Eletrodos , Humanos , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier
18.
Adv Sci (Weinh) ; 9(32): e2203523, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36089659

RESUMO

T-cell engagers (TCEs) represent a breakthrough in hematological malignancy treatment but are vulnerable to antigen escape and lack a vaccination effect. The "immunologically cold" solid tumor presents substantial challenges due to intratumor heterogeneity and an immunosuppressive tumor microenvironment (TME). Here, a methoxy poly(ethylene glycol) (mPEG)-masked CD44×PD-L1/CD3 trispecific T-cell nanoengager loaded with the STING agonist c-di-AMP (CDA) (PmTriTNE@CDA) for the treatment of triple-negative breast cancer (TNBC) is rationally designed. PmTriTNE@CDA shows tumor-specific accumulation and is preferentially unmasked in response to a weakly acidic TME to prevent on-target off-tumor toxicity. The unmasked CD44×PD-L1/CD3 trispecific T-cell nanoengager (TriTNE) targets dual tumor-associated antigens (TAAs) to redirect CD8+ T cells for heterogeneous TNBC lysis while achieving PD-L1 blockade. PmTriTNE synergized with CDA to transform the cold tumor into a hot tumor, eradicate the large established TNBC tumor, and induce protective immune memory in a 4T1 orthotopic tumor model without causing obvious toxicity. PmTriTNE@CDA shows potent efficacy in cell line-derived xenograft (CDX) and patient-derived xenograft (PDX) mouse models. This study serves as a proof-of-concept demonstration of a nanobased TCEs strategy to expand therapeutic combinations that previously could not be achieved due to systemic toxicity with the aim of overcoming TNBC heterogeneity and immunotherapy resistance.


Assuntos
Neoplasias de Mama Triplo Negativas , Humanos , Camundongos , Animais , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Antígeno B7-H1/uso terapêutico , Linhagem Celular Tumoral , Imunoterapia , Modelos Animais de Doenças , Fatores Imunológicos/uso terapêutico , Vacinação , Polietilenoglicóis/uso terapêutico , Microambiente Tumoral
19.
Anal Chim Acta ; 1199: 339567, 2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35227379

RESUMO

Electrically conductive polymer nanomaterials signify a promising class of sensing platforms in the field of electrochemistry, but their applications as electrocatalysts are commonly limited by their poor colloidal stability in aqueous media and large particle sizes. Inspired by biomineralization approaches for integrating nanoscale materials, herein, a gadolinium (Gd)-integrated polypyrrole (PPy) electrocatalyst (namely, BSA@PPy-Gd) was successfully prepared by choosing bovine serum albumin (BSA) as a stabilizer for biomimetic mineralization and polymerization in a "one-step" manner. BSA@PPy-Gd possesses outstanding water dispersibility, nanoscale morphology, and improved electrical conductivity. The electrocatalytic competency of the electrochemical (EC) sensing platform fabricated for the sensitive detection of nicardipine (NCD) was assessed. The synergy of remarkable conductivity, superior active surface area, and electrostatic interactions stimulated by the combination of BSA with the NH group of PPy on BSA@PPy-Gd and Gd increases the fast electron transfer at the analyte-electrode junction. The fabricated EC sensor, BSA@PPy-Gd/glassy carbon electrode (GCE), exhibits a current intensity greater than that of PPy/GCE, BSA/GCE, and bare GCE in terms of peak height at a pH of 7.0 in phosphate buffer solution. The newly fabricated EC sensing platform shows excellent electrocatalytic activities for the electroreduction of NCD in terms of a low detection limit (2 nM), good sensitivity, linear dynamic detection ranges (0.01-575 µM), operational stability, and repeatability and was also tested on rat and human serum specimens.


Assuntos
Polímeros , Pirróis , Animais , Biomimética , Eletrodos , Gadolínio , Nicardipino , Ratos
20.
Anal Biochem ; 411(1): 71-9, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21138725

RESUMO

Electrochemically active composite film that contains multiwalled carbon nanotubes (MWCNTs), Nafion (NF), and poly(malachite green) (PMG) has been synthesized on glassy carbon electrode (GCE), gold, and indium tin oxide (ITO) electrodes by potentiodynamic method. The presence of MWCNTs in the composite film (MWCNT-NF-PMG) enhances the surface coverage concentration (Γ) of PMG by fivefold. Similarly, an electrochemical quartz crystal microbalance study revealed enhancement in the deposition of PMG at MWCNT-NF film when compared with bare and only NF modified electrodes. The surface morphology of the composite film was studied using atomic force microscopy, which revealed that the PMG incorporated on MWCNT-NF film. The composite film exhibited enhanced electrocatalytic activity toward the mixture of biochemical compounds catechol and quinol. The electrocatalytic responses of analytes at MWCNT-NF-PMG composite film were measured using both cyclic voltammetry (CV) and differential pulse voltammetry (DPV). From electrocatalysis studies, well-separated voltammetric peaks were obtained at the composite film for catechol and quinol with a peak separation of 147mV. The sensitivity values of the composite film toward catechol and quinol by the DPV technique were 0.4 and 3.2mAmM(-1)cm(-2), respectively, which are higher than the values obtained by the CV technique. Similarly, the above-mentioned values are better than the previously reported electroanalytical values for the same analytes.


Assuntos
Catecóis/análise , Técnicas Eletroquímicas/métodos , Hidroquinonas/análise , Nanotubos de Carbono/química , Polímeros/química , Corantes de Rosanilina/química , Carbono/química , Catálise , Eletrodos , Polímeros de Fluorcarboneto/química , Vidro/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Microscopia de Força Atômica , Nanotubos de Carbono/ultraestrutura , Oxirredução , Polimerização
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