Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
1.
Anal Chem ; 95(16): 6603-6611, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-37043629

RESUMO

The total antioxidant capacity (TAC) is a key indicator of the body's resistance to oxidative stress injury in diabetic patients. The measurement of TAC is important for effectively evaluating the redox state to prevent and control the occurrence of diabetes complications. However, there is a lack of a simple, convenient, and reliable method to detect the total antioxidant capacity in diabetes. Herein, we design a novel chemiluminescent platform based on semiconducting polymer nanoparticles-manganese (SPNs-MnVII) to detect the total antioxidant capacity of urine in diabetic mice. We synthesize semiconducting polymer nanoparticles with four different structures and discover the ability of MnVII to produce singlet oxygen (1O2) that is employed to excite thiophene-based SPNs (PFODBT) to emit near-infrared chemiluminescence. Notably, the chemiluminescent intensity has a good linear relationship with the concentration of MnVII (detection limit: 2.8 µM). Because antioxidants (e.g., glutathione or ascorbic acid) can react with MnVII, such a chemiluminescent tool of SPNs (PFODBT)-MnVII can detect the glutathione or ascorbic acid with a larger responsive range. Furthermore, the total antioxidant capacity of urine from mice is evaluated via SPNs (PFODBT)-MnVII, and there are statistically significant differences between diabetic and healthy mice. Thus, this new chemiluminescent platform of SPNs (PFODBT)-MnVII is convenient, efficient, and sensitive, which is promising for monitoring antioxidant therapy of diabetes.


Assuntos
Diabetes Mellitus Experimental , Nanopartículas , Animais , Camundongos , Antioxidantes , Ácido Ascórbico , Glutationa , Manganês/química , Nanopartículas/química , Polímeros/química , Medições Luminescentes
2.
Oral Dis ; 28(8): 2239-2247, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34342085

RESUMO

OBJECTIVES: Many activities overload temporomandibular joint (TMJ) and cause mandibular condylar cartilage (MCC) degradation by inducing the expression of hypoxia-inducible factor-2α (HIF-2α). Although NF-κB signaling pathway has been reported to induce HIF-2α expression, the underlying mechanisms need to be verified. The aim was to investigate the effects of NF-κB/HIF-2α on MCC degradation induced by mechanical stress and the regulatory mechanism of NF-κB in the HIF-2α pathway. METHODS: Chondrocytes were subjected to cyclic compressive forces in a hypoxic environment. Western blotting was used to test the effects of stress on the expression of NF-κB and HIF-2α. HIF-2α siRNA and shRNA were constructed and transfected into MCC cells in vitro and in vivo to inhibit HIF-2α expression. To test the regulatory effect of the NF-κB pathway on HIF-2α, siRNA p65 was transfected into MCC. RESULTS: The results showed that mechanical stress could cause cartilage degradation and significantly increased the expression of NF-κB, HIF-2α, and downstream degradation factors (MMP13 and ADAMTs-4). Blockade of HIF-2α decreased cartilage degradation and related degradation factors. Suppression of p65 significantly decreased the expression of HIF-2α. CONCLUSIONS: Our results indicated that the upstream NF-κB pathway exerted a regulatory effect on HIF-2α in the degradation of MCC induced by stress.


Assuntos
NF-kappa B , Osteoartrite , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Condrócitos/metabolismo , Humanos , Metaloproteinase 13 da Matriz/metabolismo , NF-kappa B/metabolismo , Osteoartrite/genética , Osteoartrite/metabolismo , RNA Interferente Pequeno/metabolismo , Estresse Mecânico , Articulação Temporomandibular
3.
Yao Xue Xue Bao ; 50(5): 605-12, 2015 May.
Artigo em Zh | MEDLINE | ID: mdl-26234145

RESUMO

Polymyxin E shows effective treatment of the infection induced by resistant gramnegative bacteria, but its nephrotoxicity severely limits the clinical application of this drug. In this work, methoxypolyethylene glycols 2000 (mPEG2K)-polymyxin E (PME) was synthesized via chemical grafting reaction and had been characterized. The antimicrobial activity and cytotoxicity of mPEG2K-PME in vitro were investigated on Escherichia coli and HK-2 cells, separately. Intra-abdominal infection model was further established in order to study the therapeutic effect and the toxic effect on kidney of mice. The results showed that mPEG2K-PME exhibited significant inhibitory effect on Escherichia coli and had a lower toxicity on HK-2 cells in vitro. At the same time, mPEG2K-PME had a good efficacy in the treatment of Escherichia coli infected mice in vivo. Moreover, nephrotoxicity caused by mPEG2K-PME was significantly reduced compared to free PME. mPEG2K-PME is promising in development of new preparations with high efficiency and low toxicity.


Assuntos
Colistina/farmacologia , Infecções por Escherichia coli/tratamento farmacológico , Rim/efeitos dos fármacos , Animais , Linhagem Celular , Colistina/toxicidade , Escherichia coli/efeitos dos fármacos , Humanos , Rim/citologia , Camundongos , Polietilenoglicóis/química
4.
Nanoscale ; 15(47): 19381-19388, 2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-38014780

RESUMO

Tannic acid-based patterning is crucial for its applications in bioengineering, including multifunctional coatings, biosensors, and biochips. However, tannic acid (TA) patterning is challenging owing to the rapid polymerization kinetics of tannins and their strong adhesion towards most surfaces or objects. Herein, we report a strategy for controllable TA nanopatterning based on DNA origami templates. Protruding clustered ssDNA (pcDNA) from DNA origami tiles served as indexes for the selective deposition of TA due to the high flexibility of ssDNA and exposed aromatic bases, which provide active sites for TA-DNA interactions. Next, by exploiting the pH-sensitive degradation of TA polymers, controllable 'erasing' and 'rewriting' of TA nanopatterns were performed. Finally, combining the high adhesion and selective deposition, the TA polymers as a glue modified on the edges of origami tiles directed the reversible association/disassociation of origami multimers. Our strategy provides a simple approach for the controllable nanopatterning of TA, enabling its unique properties to tailor surface patterns for applications in materials science and biomedicine.


Assuntos
DNA , Polímeros , DNA/química
5.
Food Funct ; 14(8): 3779-3792, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-36995104

RESUMO

This study was designed to investigate the influence and effect mechanism of the filler type on the physicochemical properties, microbial numbers, and digestibility of ovalbumin emulsion gels (OEGs) during storage. Sunflower oil was emulsified with ovalbumin (20 mg mL-1) and Tween 80 (20 mg mL-1) separately to prepare ovalbumin emulsion gels (OEGs) that contained active and inactive fillers, respectively. The formed OEGs were stored at 4 °C for 0, 5, 10, 15, and 20 days. The active filler enhanced the gel hardness, water holding capacity, fat holding capacity, and surface hydrophobicity and decreased the digestibility and free sulfhydryl content during storage compared to control (unfilled) ovalbumin gel, whereas the inactive filler had the opposite effects. Protein aggregation diminished, lipid particle aggregation increased, and the amide A band shifted to a higher wavenumber for all three types of gel during storage, suggesting that the compact network structure of the OEG became rough and disordered with storage. The OEG with the active filler did not inhibit microbial growth, and the OEG with the inactive filler did not significantly promote the development of bacteria. In addition, the active filler delayed the in vitro digestion of the protein in the OEG throughout storage. Emulsion gels containing active filler facilitated the retention of the gel properties during storage, whereas emulsion gels containing inactive filler exacerbated the loss of the gel properties during storage.


Assuntos
Polissorbatos , Proteínas , Emulsões/química , Ovalbumina , Géis/química
6.
Environ Sci Technol ; 46(1): 419-25, 2012 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-22129207

RESUMO

We demonstrated that mesoporous titania beads of uniform size (about 450 µm) and high surface area could be synthesized via an alginate biopolymer template method. These mesoporous titania beads could efficiently remove Cr(VI), Cd(II), Cr(III), Cu(II), and Co(II) ions from simulated wastewater with a facile subsequent solid-liquid separation because of their large sizes. We chose Cr(VI) removal as the case study and found that each gram of these titania beads could remove 6.7 mg of Cr(VI) from simulated wastewater containing 8.0 mg·L(-1) of Cr(VI) at pH = 2.0. The Cr(VI) removal process was found to obey the Langmuir adsorption model and its kinetics followed pseudo-second-order rate equation. The Cr(VI) removal mechanism of titania beads might be attributed to the electrostatic adsorption of Cr(VI) ions in the form of negatively charged HCrO(4)(-) by positively charged TiO(2) beads, accompanying partial reduction of Cr(VI) to Cr(III) by the reductive surface hydroxyl groups on the titania beads. The used titania beads could be recovered with 0.1 mol·L(-1) of NaOH solution. This study provides a promising micro/nanostructured adsorbent with easy solid-liquid separation property for heavy metal ions removal.


Assuntos
Biopolímeros/química , Metais Pesados/isolamento & purificação , Microesferas , Tamanho da Partícula , Titânio/química , Adsorção , Biodegradação Ambiental , Íons/isolamento & purificação , Cinética , Microscopia Eletrônica de Varredura , Espectroscopia Fotoeletrônica , Porosidade , Fatores de Tempo
7.
J Colloid Interface Sci ; 608(Pt 1): 219-226, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34626968

RESUMO

Riboflavin (RF) is one of the necessary vitamins. If human body lacks RF, it will lead to inflammation and dysfunction of mouth, lips and skin. Thus sensitive and accurate determination of RF is necessary. Here, an electroactive covalent-organic framework nanobelt (COFTFPB-Thi) with thickness of 1.4 nm was prepared by amine-aldehyde condensation reaction between thionine and 1, 3, 5-tris (p-formylphenyl) benzene, which was then grown vertically on three-dimensional porous carbon derived from kenaf stem (3D-KSC) for double signal ratiometric electrochemical detection of RF. The resulted 3D-KSC/COFTFPB-Thi showed two reduction peaks at -0.08 V and -0.23 V, which came from the reduction of COFTFPB-Thi and the conjugated structure of COFTFPB-Thi, respectively. In the presence of RF, those RF molecules near the electrode surface were oxidized at 0.6 V. Then some oxidized RF (RFox) adsorbed on COFTFPB-Thi would oxidize COFTFPB-Thi into COFTFPB-Thi(ox) while other RFox adsorbed on 3D-KSC kept unchanged. When the potential was scanned from 0.6 V to -0.6 V, both COFTFPB-Thi(ox) and RFox adsorbed on 3D-KSC were reduced at -0.08 V and -0.45 V accordingly, while the reduction peak of -0.23 V of the conjugated structure of COFTFPB-Thi kept constant. When j-0.45/j-0.23 was used as the response signal, the detection limit was 44 nM and the linear range was 0.13 µM -0.23 mM. By using j-0.08/j-0.23 as the response signal, a detection limit of 90 nM and a linear range of 0.30 µM-0.23 mM (S/N = 3) were obtained. By using double signals, the measurement results can be corrected to make the results more accurate and reliable. The sensor also showed good selectivity, reproducibility and stability, which provided a good application prospects.


Assuntos
Técnicas Biossensoriais , Estruturas Metalorgânicas , Carbono , Técnicas Eletroquímicas , Eletrodos , Ouro , Humanos , Limite de Detecção , Fenotiazinas , Reprodutibilidade dos Testes , Riboflavina
8.
Ultrason Sonochem ; 89: 106149, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36055015

RESUMO

To improve the gel properties of duck egg white gel and increase the industrial value of duck egg white, the mechanisms of ultrasound and synergetic phosphorylation/ultrasound treatments were examined in this study. It was found that as the ultrasound power increased, the surface hydrophobicity, hardness, and cohesiveness of the gel system increased, and the ζ-potential and water mobility decreased. Of the two treatments, phosphorylation/ultrasound had the strongest impact on the conformation and crystallinity of the gel system and promoted the formation of high molecular polymers. Both gel systems displayed enhanced compactness, stability, and gel strength because of the enhanced protein-protein interactions via hydrogen bonds and protein aggregation, and increased the content of intramolecular ß-sheets following ultrasound treatment, and synergetic phosphorylation/ultrasound further improved the stability, water binding and gel properties. This experiment showed that ultrasound and, particularly, phosphorylation/ultrasound are effective methods to improve the gel properties of duck egg white. This study enhanced our understanding of the interactions of sodium pyrophosphate and egg white under ultrasound treatment, and promote the potential application of sodium pyrophosphate and ultrasound treatment of novel food products.


Assuntos
Patos , Clara de Ovo , Animais , Difosfatos , Clara de Ovo/química , Géis/química , Fosforilação , Polímeros , Agregados Proteicos , Água
9.
Ann Palliat Med ; 10(3): 3128-3134, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33752426

RESUMO

BACKGROUND: Appropriate and effective post-pyloric enteral nutrition (EN) is valuable for patients undergoing invasive ventilation, but blind bedside insertion of jejunal tubes is often difficult during mechanical ventilation. Here, we first report on the safety and effectiveness of inserting the jejunal tubes under the dual guidance (DG) of video-laryngoscopy and ultrasound in patients in whom jejunal tube placement during invasive mechanical ventilation is difficult. METHODS: Twenty patients in the emergency department-based intensive care unit (ICU) who were receiving invasive mechanical ventilation and had difficulty in jejunal tube placement were selected for video-laryngoscopy and ultrasound-guided jejunal tube placement (the DG group), and the outcomes were compared with patients experiencing difficult intubation before the introduction of the DG technique (the control group) in terms of the incidence of postintubation complications and the effectiveness and efficiency of nutritional support. RESULTS: The DG group had a significantly higher success rate of intubation and better nutritional status than the control group. The incidences of nasopharyngeal bleeding, dental and gingival injuries, and tracheostomy tube dislodgement were not significantly increased in the DG group, and the blood pressure and heart rate also showed no significant fluctuations. CONCLUSIONS: DG with both video-laryngoscopy and ultrasound is a safe and effective technique in patients with difficulty in jejunal tube placement.


Assuntos
Laringoscopia , Respiração Artificial , Nutrição Enteral , Humanos , Intubação Gastrointestinal , Jejuno
10.
Biomed Mater ; 17(1)2021 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-34736242

RESUMO

This study aims to construct a composite system of the tri-block polyethylene glycol injectable hydrogel (3B-PEG IH) and neural epithelial growth factor-like protein 1 (Nell-1), and to analyze its therapeutic effect on temporomandibular joint osteoarthritis (TMJOA). Sol-gel transition temperature was measured via inverting test. The viscoelastic modulus curves was measured by rheometer. Degradation and controlled release profiles of 3B-PEG IH were drawnin vitro.In vivogel retention and biocompatibility were completed subcutaneously on the back of rats. After primary chondrocytes were extracted and identified, the cell viability in 3B-PEG IH was measured. Evaluation of gene expression in hydrogel was performed by real-time polymerase chain reaction. TMJOA rabbits were established by intra-articular injection of type II collagenase. Six weeks after composite systems being injected, gross morphological score, micro-CT, histological staining and grading were evaluated. The rusults showed that different types of 3B-PEG IH all reached a stable gel state at 37 °C and could support the three-dimensional growth of chondrocytes, but poly(lactide-co-caprolactone)-block-poly(ethyleneglycol)-block-poly(lactide-co-caprolactone) (PLCL-PEG-PLCL) hydrogel had a wider gelation temperature range and better hydrolytic stability for about 4 weeks. Its controlled release curve is closest to the zero-order release kinetics.In vitro, PLCL-PEG-PLCL/Nell-1 could promote the chondrogenic expression and reduce the inflammatory expression.In vivo, TMJOA rabbits were mainly characterized by the disorder of cartilage structure and the destruction of subchondral bone. However, PLCL-PEG-PLCL/Nell-1 could reverse the destruction of the subchondral trabecula, restore the fibrous and proliferative layers of the surface, and reduce the irregular hyperplasia of fibrocartilage layer. In conclusion, by comparing the properties of different 3B-PEG IH, 20 wt% PLCL-PEG-PLCL hydrogel was selected as the most appropriate material. PLCL-PEG-PLCL/Nell-1 composite could reverse osteochondral damage caused by TMJOA, Nfatc1-Runx3 signaling pathway may play a role in it. This study may provide a novel, minimally-invasive therapeutic strategy for the clinical treatment of TMJOA.


Assuntos
Osteoartrite , Animais , Condrócitos , Condrogênese , Hidrogéis , Osteoartrite/patologia , Osteoartrite/terapia , Poliésteres/química , Coelhos , Ratos , Articulação Temporomandibular/metabolismo , Articulação Temporomandibular/patologia
11.
Nanoscale ; 12(15): 8248-8254, 2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32239032

RESUMO

Probes functioning in the second near-infrared window (1000-1700 nm, NIR-II) exhibit higher resolution and diminished auto-fluorescence compared to those in the traditional NIR region (700-950 nm). Here, we designed and synthesized rare earth ion doped probes with core/shell/shell structures and bright luminescence in the NIR-II region excited at 808 nm. With the doping of Ce3+ ions, the emission intensity of Er3+ at 1530 nm increased 10 times, while the upconversion luminescence decreased to less than 1%. After being modified with polyacrylic acid and polyethylene glycol, the as-obtained water-soluble probe exhibits continuous high-resolution for distinguishing 0.25 mm blood vessels even 10 h after injection. Noteworthily, the imaging of tumors was achieved by injecting the probe, indicating that the designed NIR-II probe has sufficient brightness and the ability to passively target tumor tissue.


Assuntos
Vasos Sanguíneos/diagnóstico por imagem , Elementos da Série dos Lantanídeos/química , Nanopartículas Metálicas/química , Imagem Óptica/métodos , Resinas Acrílicas/química , Animais , Vasos Sanguíneos/metabolismo , Elementos da Série dos Lantanídeos/administração & dosagem , Elementos da Série dos Lantanídeos/farmacocinética , Luminescência , Nanopartículas Metálicas/administração & dosagem , Camundongos , Neoplasias/diagnóstico por imagem , Neoplasias/metabolismo , Polietilenoglicóis/química , Espectroscopia de Luz Próxima ao Infravermelho , Propriedades de Superfície
12.
J Pharm Sci ; 108(6): 2012-2021, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30639741

RESUMO

Polygeline is a highly promising drug carrier-oriented material for important applications in pharmacy field due to its low-cost and unique properties similar to albumin. In this study, polygeline-bound paclitaxel nanoparticles (Npb-PTXS) were fabricated through a combination of low-pressure emulsification and high-pressure homogenization. The effects of a series of production parameters on mean particle size, particle size distribution and drug loading of Npb-PTXS were systematically evaluated. The characteristics of Npb-PTXS, such as surface morphology, physical status of paclitaxel (PTX) in Npb-PTXS, redispersibility of Npb-PTXS in purified water and bioavailability in vivo were also investigated. It is revealed that the optimal preparation conditions included an aqueous phase pH value of about 6.5, protein mass concentration of 0.33%, with mass ratio of PTX to protein of 30%, high pressure of 1200 bar, high-pressure passes of 25 times and low-pressure emulsifying passes of 20 times. Obtained Npb-PTXS shows good resolubility compared to commercially available Abraxane®, containing round or oval shaped particles with mean particle size of around 188.3 nm, polydispersity index of 0.163 and zeta potential of -31.1 mV. PTX in Npb-PTX is amorphous, and its content is approximately 12.04%. Encapsulation efficiency of Npb-PTXS reaches 81.2%. Moreover, in vivo pharmacokinetic studies showed that the intravenous relative bioavailability of Npb-PTXS to Abraxane was 83.89%.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Paclitaxel/administração & dosagem , Poligelina/química , Administração Intravenosa , Paclitaxel Ligado a Albumina/administração & dosagem , Paclitaxel Ligado a Albumina/farmacocinética , Animais , Antineoplásicos Fitogênicos/farmacocinética , Disponibilidade Biológica , Emulsões , Masculino , Modelos Animais , Nanopartículas/química , Paclitaxel/farmacocinética , Tamanho da Partícula , Ratos , Solubilidade , Organismos Livres de Patógenos Específicos
13.
Bioresour Technol ; 240: 171-176, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28279609

RESUMO

In present study, two column-type sequencing batch reactors with alternative anoxic/aerobic phases were operated and compared under partial nitrification and full nitrification modes by controlling different dissolved oxygen (DO) conditions. During steady state, the characterizations of extracellular polymeric substances (EPS) from two reactors were qualitatively and quantitatively analyzed through chemical and spectroscopic approaches. Data implied that partial nitrification reactor had relatively higher total nitrogen (TN) removal efficiency and loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) contents. According to excitation emission matrix (EEM) spectra, LB-EPS and TB-EPS from two kinds of reactors expressed similar fluorescence peak locations but different intensities. Fluorescence regional integration (FRI) further suggested that Region IV was the main fraction in both types of EPS fractions. Moreover, TB-EPS exhibited a greater number of molecular weight fractions than those of LB-EPS. Both EPS fractions had similar functional groups, which represented the complex nature of EPS compositions.


Assuntos
Reatores Biológicos , Nitrificação , Peso Molecular , Nitrogênio , Polímeros
14.
Int J Nanomedicine ; 10: 5383-96, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26347257

RESUMO

Vaginal small interfering RNA (siRNA) delivery provides a promising strategy for the prevention and treatment of vaginal diseases. However, the densely cross-linked mucus layer on the vaginal wall severely restricts nanoparticle-mediated siRNA delivery to the vaginal epithelium. In order to overcome this barrier and enhance vaginal mucus penetration, we prepared spray-dried powders containing siRNA-loaded nanoparticles. Powders with Pluronic F127 (F127), hydroxypropyl methyl cellulose (HPMC), and mannitol as carriers were obtained using an ultrasound-assisted spray-drying technique. Highly dispersed dry powders with diameters of 5-15 µm were produced. These powders showed effective siRNA protection and sustained release. The mucus-penetrating properties of the powders differed depending on their compositions. They exhibited different potential of opening mesh size of molecular sieve in simulated vaginal mucus system. A powder formulation with 0.6% F127 and 0.1% HPMC produced the maximum increase in the pore size of the model gel used to simulate vaginal mucus by rapidly extracting water from the gel and interacting with the gel; the resulting modulation of the molecular sieve effect achieved a 17.8-fold improvement of siRNA delivery in vaginal tract and effective siRNA delivery to the epithelium. This study suggests that powder formulations with optimized compositions have the potential to alter the steric barrier posed by mucus and hold promise for effective vaginal siRNA delivery.


Assuntos
Nanopartículas/química , Pós/química , RNA Interferente Pequeno/química , Vagina/efeitos dos fármacos , Administração Intravaginal , Animais , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Derivados da Hipromelose/química , Manitol/química , Muco/efeitos dos fármacos , Tamanho da Partícula , Poloxâmero/química , Coelhos , Ratos , Ratos Endogâmicos Lew , Reologia , Ultrassom
15.
J Agric Food Chem ; 62(52): 12678-85, 2014 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-25472604

RESUMO

Amphiphilic graft copolymers were prepared from ß-conglycinin-dextran conjugates hydrolyzed by trypsin at a degree of hydrolysis (DH) of 2.2%. Nanoparticles were prepared from ß-conglycinin, ß-conglycinin-dextran conjugates (CDC), and amphiphilic hydrolysates of ß-conglycinin-dextran conjugates at DH 2.2% (CDCH) by a desolvation method. All of the nanoparticle samples exhibited spherical structures, as evidenced by dynamic light scattering, transmission electron microscopy, and small-angle X-ray scattering. The nanoparticles prepared from amphiphilic hydrolysates of ß-conglycinin-dextran conjugates at DH 2.2% (CDCHN) exhibited higher interfacial pressure and dilatational modulus after long-term absorption at the oil-water interface compared with nanoparticles prepared from ß-conglycinin (CN) and ß-conglycinin-dextran conjugates (CDCN). This might be mainly associated with the higher surface hydrophobicity of CDCHN, which enhanced adsorption and intermolecular interactions of nanoparticles in the adsorbed layer.


Assuntos
Antígenos de Plantas/química , Dextranos/química , Globulinas/química , Proteínas de Armazenamento de Sementes/química , Proteínas de Soja/química , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas/química , Polímeros/química , Propriedades de Superfície , Tripsina/química , Água/química
16.
J Agric Food Chem ; 61(32): 7838-47, 2013 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-23865496

RESUMO

A lipophilic protein nanoparticle (LPP) was fabricated by ultrasonication of the soy lipophilic protein (LP), which contains hydrophobic proteins and phospholipids. This LPP (Rh = 136 ± 0.8 nm, ζ-potential = -20 mV, pH 7.0) had an improved dispersibility and acted as an emulsifier. The oil/water (O/W) emulsion stabilized by this LPP exhibited superior physical stability over long-term storage (8 weeks), during a stress storage test (200 mM NaCl addition and heating at 90 °C), and in the presence of Tween 20 (1.0-4.0 wt %), in contrast to those emulsions stabilized by ß-conglycinin and glycinin. Langmuir-Blodgett method and interface pressure determination revealed that LPP formed rigid and rough granular film at air/water interface. The excellent stability of emulsions stabilized by LPP highlights the synergic effect between hydrophobic proteins and phospholipids. These findings suggest that the complexes of hydrophobic protein aggregates and biosurfactant could form a stable interface which could be developed into a novel strategy to fabricate a stable food emulsion.


Assuntos
Nanopartículas/química , Proteínas de Soja/química , Água/química , Emulsões/química , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Polissorbatos/química , Tensoativos/química
17.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 30(5): 493-7, 2012 Oct.
Artigo em Zh | MEDLINE | ID: mdl-23173313

RESUMO

OBJECTIVE: To analyze the mechanism of fluorine by systemic analysis of fluorination-demineralization-remineralization experiments. METHODS: The enamel specimens were randomly assigned to untreated group (group A), non-fluoride group (group B), low-fluoride group (group C) and high-fluoride group (group D). The in vitro model of fluoride enamel was established in group C and D. Based on that, the establishment of demineralization model and remineralization experiment by pH-cycling in group B, C and D were followed. All enamel specimens were observed by stereomicroscope and scanning electron microscope and compared in surface microhardness value. RESULTS: There was distinct difference in micro-morphologic appearance on fluoride enamel surface. Artificial caries of fluoride enamel showed a relatively complete surface, the surface microhardness after demineralization and remineralization in fluoride group was higher than non-fluoride group (P < 0.05). CONCLUSION: The fluorinated enamel can enhance cariostatic potential and remineralization capacity of dental enamel.


Assuntos
Flúor , Remineralização Dentária , Cárie Dentária , Esmalte Dentário , Fluoretos , Humanos , Fosfatos , Desmineralização do Dente
18.
Drug Des Devel Ther ; 6: 341-7, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23185117

RESUMO

BACKGROUND: Levodopa is the gold standard in the treatment of Parkinson's disease (PD). However, long-term levodopa replacement therapy is accompanied by abnormal involuntary movements (AIMs), known as levodopa-induced dyskinesia (LID). Until now, the precise mechanisms of LID were only partially understood. Previous studies have shown that continuous dopamine stimulation was helpful in reducing the expression of LID. In addition to dopamine D1 receptor, glutamatergic receptors such as α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor also contribute to the expression of LID. The current authors have previously reported that levodopa/benserazide-loaded microspheres could ameliorate the expression of LID by reducing the protein kinase A signaling pathway in dyskinetic rats. However, whether AMPA receptor is involved in the mechanism by which levodopa/benserazide-loaded microspheres ameliorate the expression of LID in dyskinetic rats was unknown. METHODS: In the present study, as reported previously, levodopa and benserazide were loaded by poly(lactic-co-glycolic acid) microspheres, which can release levodopa and benserazide in a sustained manner. 6-Hydroxydopamine was injected into the right medial forebrain bundle to produce a rat model of PD. Then valid PD rats were treated with levodopa plus benserazide for 3 weeks to induce a rat model of LID. Dyskinetic rats were treated with levodopa/beserazide-loaded microspheres containing levodopa (6 mg/kg) plus benserazide (15 mg/kg) or same dose of levodopa plus benserazide. Abnormal involuntary movements were measured in rats on days 1, 5, 10, 15, and 20 during the treatment. The levels of GluR1 at serine-831 (pGluR1S831) and serine-845 (pGluR1S845) were determined by Western blot. Arc and proenkephalin (Penk) levels were measured by real-time polymerase chain reaction. RESULTS: Three-week levodopa plus benserazide treatment induced dyskinesia in PD rats. Levodopa/benserazide-loaded microsphere-treated dyskinetic rats showed lower AIM scores than levodopa plus benserazide-treated dyskinetic rats. Microsphere treatment downregulated the phosphrylated levels of pGluR1S831 and pGluR1S845 in the striatum of dyskinetic rats. In addition, microsphere treatment reduced the levels of Arc and Penk. CONCLUSION: These data indicated that levodopa/benserazide-loaded microspheres could be used to ameliorate the expression of LID by reducing the expression of pGluR1S831 and pGluR1S845 as well as Arc and Penk.


Assuntos
Antiparkinsonianos/toxicidade , Benserazida/toxicidade , Discinesia Induzida por Medicamentos/etiologia , Levodopa/toxicidade , Receptores de AMPA/genética , Animais , Antiparkinsonianos/administração & dosagem , Antiparkinsonianos/farmacologia , Benserazida/administração & dosagem , Benserazida/farmacologia , Western Blotting , Preparações de Ação Retardada , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Portadores de Fármacos/química , Combinação de Medicamentos , Discinesia Induzida por Medicamentos/prevenção & controle , Feminino , Ácido Láctico/química , Levodopa/administração & dosagem , Levodopa/farmacologia , Microesferas , Oxidopamina/toxicidade , Transtornos Parkinsonianos/tratamento farmacológico , Fosforilação/efeitos dos fármacos , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real
19.
Neuroreport ; 21(12): 837-40, 2010 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-20631586

RESUMO

Parkinson's disease is a neurodegenerative disorder characterized by progressive loss of dopaminergic neurons in the substantia niara. Levodopa remains the most effective drug in the treatment of Parkinson's disease. Unfortunately, with disease progression, levodopa reduces Parkinsonism at the cost of evoking abnormal involuntary movements known as levodopa-induced dyskinesia (LID). In this study, we found that levodopa/benserazide-loaded biodegradable microspheres reduce the expression of LID, which was easily evoked by administrating of the same dose of levodapa and benserazide in rats with Parkinson's disease. Moreover, levodopa/benserazide-loaded biodegradable microspheres can improve the stepping of the lesioned forepaw in rats with Parkinson's disease. These data showed that levodopa/benserazide-loaded biodegradable microspheres might be useful in the treatment of Parkinson's disease and reducing the expression of LID in rats.


Assuntos
Benserazida/administração & dosagem , Materiais Biocompatíveis/metabolismo , Discinesia Induzida por Medicamentos/tratamento farmacológico , Levodopa/administração & dosagem , Microesferas , Transtornos Parkinsonianos/tratamento farmacológico , Animais , Antiparkinsonianos/administração & dosagem , Materiais Biocompatíveis/administração & dosagem , Modelos Animais de Doenças , Progressão da Doença , Combinação de Medicamentos , Sinergismo Farmacológico , Discinesia Induzida por Medicamentos/prevenção & controle , Feminino , Coxeadura Animal/tratamento farmacológico , Coxeadura Animal/etiologia , Ratos , Ratos Sprague-Dawley , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA