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1.
J Am Chem Soc ; 146(28): 19239-19248, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38949598

RESUMO

Advanced in vitro diagnosis technologies are highly desirable in early detection, prognosis, and progression monitoring of diseases. Here, we engineer a multiplex protein biosensing strategy based on the tunable liquid confinement self-assembly of multi-material heterochains, which show improved sensitivity, throughput, and accuracy compared to standard ELISA kits. By controlling the material combination and the number of ligand nanoparticles (NPs), we observe robust near-field enhancement as well as both strong electromagnetic resonance in polymer-semiconductor heterochains. In particular, their optical signals show a linear response to the coordination number of the semiconductor NPs in a wide range. Accordingly, a visible nanophotonic biosensor is developed by functionalizing antibodies on central polymer chains that can identify target proteins attached to semiconductor NPs. This allows for the specific detection of multiple protein biomarkers from healthy people and pancreatic cancer patients in one step with an ultralow detection limit (1 pg/mL). Furthermore, rapid and high-throughput quantification of protein expression levels in diverse clinical samples such as buffer, urine, and serum is achieved by combining a neural network algorithm, with an average accuracy of 97.3%. This work demonstrates that the heterochain-based biosensor is an exemplary candidate for constructing next-generation diagnostic tools and suitable for many clinical settings.


Assuntos
Técnicas Biossensoriais , Aprendizado de Máquina , Humanos , Técnicas Biossensoriais/métodos , Biomarcadores/análise , Nanopartículas/química , Semicondutores , Ensaios de Triagem em Larga Escala , Neoplasias Pancreáticas , Polímeros/química
2.
Mol Pharm ; 17(6): 1816-1826, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32212701

RESUMO

Insult to the central nervous system (CNS) results in an early inflammatory response, which can be exploited as an initial indicator of neurological dysfunction. Nanoparticle drug delivery systems provide a mechanism to increase the uptake of drugs into specific cell types in the CNS such as microglia, the resident macrophage responsible for innate immune response. In this study, we developed two nanoparticle-based carriers as potential theranostic systems for drug delivery to microglial cells. Poly(lactic-co-glycolic) acid (PLGA)- and l-tyrosine polyphosphate (LTP)-based nanoparticles were synthesized to encapsulate the magnetic resonance imaging (MRI) contrast agent, gadolinium-diethylenetriaminepentaacetic acid (Gd[DTPA]), or the anti-inflammatory drug, rolipram. Robust uptake of both polymer formulations by microglial cells was observed with no evidence of toxicity. In mixed glial cultures, we observed a preferential internalization of nanoparticles by microglia compared to that of astrocytes. Moreover, exposure of our nanoparticles to microglial cells did not induce the release of the proinflammatory cytokines, tumor necrosis factor α (TNF-α), interleukin-1 ß (IL-1ß), or interleukin-6 (IL-6). These studies provide a foundation for the development of LTP nanoparticles as a platform for the delivery of imaging agents and drugs to the sites of neuroinflammation.


Assuntos
Anti-Inflamatórios/administração & dosagem , Microglia/metabolismo , Nanopartículas/química , Animais , Anti-Inflamatórios/química , Linhagem Celular , Imunofluorescência , Imageamento por Ressonância Magnética , Metabolômica , Camundongos , Microscopia Confocal , Organofosfatos/química , Polímeros/química
3.
Beijing Da Xue Xue Bao Yi Xue Ban ; 47(6): 1005-9, 2015 Dec 18.
Artigo em Zh | MEDLINE | ID: mdl-26679666

RESUMO

OBJECTIVE: To evaluate the micro-push-out bond strengths of prefabricated glass fiber posts with poly-dopamine functionalized to root dentin using resin cements, contrasted with silane treatment. METHODS: In the study, 30 glass fiber posts were randomly divided into 3 groups (10 posts in each group) for different surface treatments. Group 1, treated with poly-dopa; Group 2, treated with silane coupling agent for 60s; Group 3, no surface treatment (Control group). The 30 extracted human, single-rooted teeth were endodontically treated and a 9 mm post space was prepared in each tooth with post drills provided by the manufacturer. Following post cementation, the specimens were stored in distilled water at 37 °C for 7 days. The micro-push-out bond strengths were tested using a universal testing machine (0.5 mm/min), and the failure modes were examined with a stereomicroscope. The data of the three groups were statistically analyzed using the one-way ANOVA test(α= 0.05). RESULTS: The bond strengths were (7.909 ± 1.987) MPa for Group 1, (5.906 ± 0.620) MPa for Group 2, and 4.678 ± 0.910 MPa for Group 3. The bond strength of poly-dopamine group was significantly higher than that of the silane group (P<0.05). CONCLUSION: Contrasted with silane treatment, surface poly-dopamine functionalization was confirmed to be a more reliable method for improving the bond strength of resin luting agents to fiber posts.


Assuntos
Adesivos Dentinários , Dopamina , Técnica para Retentor Intrarradicular , Silanos , Cimentação , Colagem Dentária , Dentina , Vidro , Humanos , Teste de Materiais , Cimentos de Resina , Raiz Dentária
4.
Mol Pharm ; 10(5): 1836-44, 2013 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-23510151

RESUMO

The concept of gene therapy is promising; however, the perceived risks and side effects associated with this technology have severely dampened the researchers' enthusiasm. Thus, the development of a nonviral gene vector without immunological effects and with high transfection efficiency is necessary. Currently, most nonviral vectors have failed to achieve the in vivo transfection efficiencies of viral vectors due to their toxicity, rapid clearance, and/or inappropriate release rates. Although our previous studies have successfully demonstrated the controlled-release of plasmid DNA (pDNA) polyplexes encapsulated into nanoparticles formulated with l-tyrosine polyphosphate (LTP-pDNA nanoparticles), the in vivo transfection capabilities and immunogenicity of this delivery system have yet to be examined. Thus, we evaluate LTP-pDNA nanoparticles in an in vivo setting via injection into rodent uterine tissue. Our results demonstrate through X-gal staining and immunohistochemistry of uterine tissue that transfection has successfully occurred after a nine-day incubation. In contrast, the results for the control nanoparticles show results similar to those of shams. Furthermore, reverse transcriptase polymerase chain reaction (RT-PCR) from the injected tissues confirms the transfection in vivo. To examine the immunogenicity, the l-tyrosine polyphosphate (LTP) nanoparticles have been evaluated in a mouse model. No significant differences in the activation of the innate immune system are observed. These data provide the first report for the potential use of controlled-release nanoparticles formulated from an amino acid based polymer as an in vivo nonviral vector for gene therapy.


Assuntos
Técnicas de Transferência de Genes , Nanopartículas/química , Organofosfatos/química , Polímeros/química , Animais , Feminino , Terapia Genética , Vetores Genéticos , Imunidade Inata , Camundongos , Nanocápsulas/administração & dosagem , Nanocápsulas/química , Nanopartículas/administração & dosagem , Organofosfatos/administração & dosagem , Organofosfatos/imunologia , Plasmídeos/administração & dosagem , Plasmídeos/genética , Polímeros/administração & dosagem , Ratos Endogâmicos WKY , Transfecção , Útero/imunologia , Útero/metabolismo
5.
Mol Pharm ; 9(11): 3089-98, 2012 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-22957928

RESUMO

Many anticancer drugs have been established clinically, but their efficacy can be compromised by nonspecific toxicity and an inability to reach the desired cancerous intracellular spaces. In order to address these issues, researchers have explored the use of folic acid as a targeted moiety to increase specificity of chemotherapeutic drugs. To expand upon such research, we have conjugated folic acid to functionalized poly(ethylene glycol) and subsequently decorated the surface of l-tyrosine polyphosphate (LTP) nanoparticles. These nanoparticles possess the appropriate size (100-500 nm) for internalization as shown by scanning electron microscopy and dynamic light scattering. Under simulated physiological flow, LTP nanoparticles decorated with folic acid (targeted nanoparticles) show a 10-fold greater attachment to HeLa, a cervical cancer cell line, compared to control nanoparticles and to human dermal fibroblasts. The attachment of these targeted nanoparticles progresses at a linear rate, and the strength of this nanoparticle attachment is shown to withstand shear stresses of 3.0 dyn/cm(2). These interactions of the targeted nanoparticles to HeLa are likely a result of a receptor-ligand binding, as a competition study with free folic acid inhibits the nanoparticle attachment. Finally, the targeted nanoparticles encapsulated with a silver based drug show increased efficacy in comparison to nondecorated (plain) nanoparticles and drug alone against HeLa cells. Thus, targeted nanoparticles are a promising delivery platform for developing anticancer therapies that overexpress the folate receptors (FRs).


Assuntos
Portadores de Fármacos , Ácido Fólico/metabolismo , Nanopartículas/química , Organofosfatos/metabolismo , Polímeros/metabolismo , Neoplasias do Colo do Útero/metabolismo , Células Cultivadas , Derme/citologia , Derme/metabolismo , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Imunofluorescência , Receptor 1 de Folato/metabolismo , Humanos , Ácido Láctico/química , Ácido Láctico/metabolismo , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Polietilenoglicóis/química , Polietilenoglicóis/metabolismo , Ácido Poliglicólico/química , Ácido Poliglicólico/metabolismo , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Neoplasias do Colo do Útero/patologia
6.
J Hazard Mater ; 433: 128756, 2022 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-35358818

RESUMO

Nanoplastic has become a prominent threat to the aquatic ecosystem, and the cost-effective technologies for controlling that are still insufficient. The aim of this study is to use contaminated corncobs collected in mining area to prepare functional mesoporous biochar (MBC) and to investigate its ability to remove polystyrene nanoplastics (PSNPs) from water. The adsorption of PSNPs by MBC could be better described by the Sips isotherm and followed the second-order kinetics, with the theoretical maximum adsorption capacity of MBC for PSNPs was 56.02 mg·g-1. Then the PSNPs adsorbed on MBC could be hydrothermally degraded and the biochar could be simultaneously regenerated. The ability was affected by various factors, including oxygen-containing functional groups, metallic components, superoxide radicals and holes. The degradation products were dominated as low-molecule-weight oligomers and the main possible pathways involved scission, hydrolysis and radical reaction. The findings highlight the great potential of biochar prepared using contaminated biowaste in mining area to remove the nanoplastic pollutants in the aqueous environment.


Assuntos
Microplásticos , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Ecossistema , Cinética , Poliestirenos , Água , Poluentes Químicos da Água/análise , Zea mays
7.
Langmuir ; 26(2): 908-14, 2010 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-19754148

RESUMO

Amorphous fluorinated carbon (a-CF(x)) films have a variety of potential technological applications. In most such applications these films are exposed to air and undergo partial surface oxidation. X-ray photoemission spectroscopy has been used to study the oxidation of fresh a-CF(x) films deposited by magnetron sputtering. The oxygen sticking coefficient measured by exposure to low pressures (<10(-3) Torr) of oxygen at room temperature is on the order of S approximately 10(-6), indicating that the surfaces of these films are relatively inert to oxidation when compared with most metals. The X-ray photoemission spectra indicate that the initial stages of oxygen exposure (<10(7) langmuirs) result in the preferential oxidation of the carbon atoms with zero or one fluorine atom, perhaps because these carbon atoms are more likely to be found in configurations with unsaturated double bonds and radicals than carbon atoms with two or three fluorine atoms. Exposure of the a-CF(x) film to atmospheric pressures of air (effective exposure of 10(12) langmuirs to O(2)) results in lower levels of oxygen uptake than the low pressure exposures (<10(7) langmuirs). It is suggested that this is the result of oxidative etching of the most reactive carbon atoms, leaving a relatively inert surface. Finally, low pressure exposures to air result in the adsorption of both nitrogen and oxygen onto the surface. Some of the nitrogen adsorbed on the surface at low pressures is in a reversibly adsorbed state in the sense that subsequent exposure to low pressures of O(2) results in the displacement of nitrogen by oxygen. Similarly, when an a-CF(x) film oxidized in pure O(2) is exposed to low pressures of air, some of the adsorbed oxygen is displaced by nitrogen. It is suggested that these forms of nitrogen and oxygen are bound to free radical sites in the film.


Assuntos
Carbono/química , Flúor/química , Membranas Artificiais , Nitrogênio/química , Oxirredução , Oxigênio/química , Espectrometria por Raios X
8.
J Control Release ; 328: 100-111, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-32858074

RESUMO

Single reactive oxygen species (ROS)-mediated therapy, photodynamic therapy (PDT) or chemodynamic therapy (CDT) is severely hindered in hypoxic solid tumor. Herein, to address the urgent challenge, a hypoxia-activated ROS burst liposome has been fabricated to achieve synergistic PDT/CDT that is initiated by the structural dissociation of poly(metronidazole) liposome in hypoxic tumor microenvironment (TME). The therapeutic enhancement of our ROS-blasting treatment is simultaneously regulated by external light-initiated PDT and endogenous iron oxide nanoclusters-triggered CDT, which is synergistically boosted and amplified by localized mild hyperthermia under 808/660 nm coirradiation. More importantly, in vitro and in vivo experiments demonstrate that electron-affinic poly(aminoimidazole) product from hypoxia-responsive transition of poly(metronidazole) polymers could efficiently enhance hypoxic cell apoptosis and induce solid tumor ablation. Thus, this work offers a potential hypoxia-activated ROS burst-PDT/CDT strategy with a superior antitumor efficacy, highlighting a promising clinical application.


Assuntos
Lipossomos , Fotoquimioterapia , Linhagem Celular Tumoral , Humanos , Hipertermia , Hipóxia , Espécies Reativas de Oxigênio
9.
Biomaterials ; 26(13): 1585-93, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15522760

RESUMO

We have developed a crosslinked hyaluronic acid (HA) film with DNA incorporated within its structure and have characterized this system for its efficacy in sustained transferring of a vector encoding mouse hyaluronan synthase 2 (Has2). Analysis of the DNA release kinetics indicated that the HA films degraded when treated with hyaluronidase and that they released DNA over a prolonged period of time. Gel electrophoresis revealed that this DNA was intact and immunohistochemical analysis verified the transfection capabilities of DNA release samples. The ability of released DNA encoding Has2 to promote HA synthesis was confirmed by quantifying the amount of HA produced by COS-1 cells that were transfected with release samples. The intended future application of the HA films is in prevention of post-operative peritoneal adhesions. In addition to serving as a physical barrier, the film would function as a vehicle for sustained delivery of DNA encoding Has2, which would promote the synthesis of HA in transfected tissues.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Glucuronosiltransferase/biossíntese , Glucuronosiltransferase/genética , Ácido Hialurônico/química , Plasmídeos/administração & dosagem , Plasmídeos/farmacocinética , Transfecção/métodos , Implantes Absorvíveis , Animais , Células COS , Chlorocebus aethiops , Materiais Revestidos Biocompatíveis/química , Reagentes de Ligações Cruzadas , Técnicas de Transferência de Genes , Vetores Genéticos/genética , Glucuronosiltransferase/administração & dosagem , Hialuronan Sintases , Teste de Materiais , Plasmídeos/genética
10.
Biofabrication ; 7(4): 045001, 2015 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-26418306

RESUMO

Drug-loaded microneedle arrays for transdermal delivery of a chemotherapeutic drug were fabricated using multi-material microstereolithography (µSL). These arrays consisted of twenty-five poly(propylene fumarate) (PPF) microneedles, which were precisely orientated on the same polymeric substrate. To control the viscosity and improve the mechanical properties of the PPF, diethyl fumarate (DEF) was mixed with the polymer. Dacarbazine, which is widely used for skin cancer, was uniformly blended into the PPF/DEF solution prior to crosslinking. Each microneedle has a cylindrical base with a height of 700 µm and a conical tip with a height of 300 µm. Compression test results and characterization of the elastic moduli of the PPF/DEF (50:50) and PPF/drug mixtures indicated that the failure force was much larger than the theoretical skin insertion force. The release kinetics showed that dacarbazine can be released at a controlled rate for five weeks. The results demonstrated that the PPF-based drug-loaded microneedles are a potential method to treat skin carcinomas. In addition, µSL is an attractive manufacturing technique for biomedical applications, especially for micron-scale manufacturing.


Assuntos
Bioimpressão/instrumentação , Dacarbazina/farmacologia , Fumaratos/química , Análise em Microsséries/instrumentação , Polipropilenos/química , Cromatografia em Gel , Força Compressiva/efeitos dos fármacos , Liberação Controlada de Fármacos , Módulo de Elasticidade/efeitos dos fármacos , Desenho de Equipamento , Fluorescência , Peso Molecular , Espectroscopia de Prótons por Ressonância Magnética , Viscosidade
11.
Dent Mater J ; 34(6): 740-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26632222

RESUMO

UNLABELLED: This paper evaluated the push-out bond strengths of glass fiber posts with poly-dopamine (poly-dopa) functionalized after etching with H2O2. Forty extracted human, single-rooted teeth were endodontically treated and a 9-mm post space was prepared in each tooth with post drills provided by the manufacturer. Specimens were randomly assigned into four groups (n=10 per group), depending on post surface treatment used: group C (control); group D (poly-dopa); group H (H2O2); and group HD (H2O2+poly-dopa). The push-out test was performed using a universal testing machine. RESULTS: Bond strengths (MPa) were as follows: 4.678±0.911 (group C); 7.909±1.987 (group D); 6.519±0.893 (group H); and 9.043±1.596 (group HD). The bond strength of the resin cement to posts functionalized with poly-dopa was not affected by H2O2 pre-treatment, while conditioning using H2O2+poly-dopa resulted in higher bond strengths than H2O2 treatment only. Compared to H2O2 treatment, the bond strength of poly-dopa conditioning was superior.


Assuntos
Colagem Dentária , Vidro/química , Peróxido de Hidrogênio/química , Indóis/química , Polímeros/química , Técnica para Retentor Intrarradicular , Análise do Estresse Dentário , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Distribuição Aleatória , Cimentos de Resina/química , Propriedades de Superfície
12.
Biomaterials ; 25(1): 147-57, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14580918

RESUMO

Hyaluronan is a naturally occurring polymer that has enjoyed wide successes in biomedical and cosmetic applications as coatings, matrices, and hydrogels. For controlled delivery applications, formulating native hyaluronan into microspheres could be advantageous but has been difficult to process unless organic solvents are used or hyaluronan has been modified by etherification. Therefore, we present a novel method of preparing hyaluronan microspheres using adipic dihydrazide mediated crosslinking chemistry. To evaluate their potential for medical applications, hyaluronan microspheres are incorporated with DNA for gene delivery or conjugated with an antigen for cell-specific targeting. The results show that our method, originally developed for preparing hyaluronan hydrogels, generates robust microspheres with a size distribution of 5-20mum. The release of the encapsulated plasmid DNA can be sustained for months and is capable of transfection in vitro and in vivo. Hyaluronan microspheres, conjugated with monoclonal antibodies to E- and P-selectin, demonstrate selective binding to cells expressing these receptors. In conclusion, we have developed a novel microsphere preparation using native hyaluronan that delivers DNA at a controlled rate and adaptable for site-specific targeting.


Assuntos
Materiais Revestidos Biocompatíveis/química , Preparações de Ação Retardada/química , Marcação de Genes/métodos , Ácido Hialurônico/química , Plasmídeos/administração & dosagem , Transfecção/métodos , Animais , Complexo Antígeno-Anticorpo/metabolismo , Adesão Celular , Células Cultivadas , Materiais Revestidos Biocompatíveis/síntese química , Materiais Revestidos Biocompatíveis/farmacocinética , Preparações de Ação Retardada/síntese química , Sistemas de Liberação de Medicamentos/métodos , Células Endoteliais/metabolismo , Humanos , Ácido Hialurônico/farmacocinética , Substâncias Macromoleculares , Teste de Materiais , Microesferas , Conformação Molecular , Tamanho da Partícula , Plasmídeos/química , Ratos/genética , Propriedades de Superfície , Veias Umbilicais/metabolismo
13.
J Biomater Appl ; 27(8): 1017-31, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22207610

RESUMO

L-Tyrosine polyurethanes (LTUs) have been synthesized by structural modification of the poly (amino acid) backbone to circumvent the problems associated with the processing of poly (amino acids) arising from their high crystallinity, insolubility in common organic solvents, and high glass-transition and melting temperatures. Additionally, problems such as unpredictable swelling characteristics, change in conformation, and uncontrolled enzymatic degradation have severely restricted the use of poly (amino acids). In contrast, LTUs are designed to retain their superior physico-chemical properties, while incorporating biodegradability through enzymatic, hydrolytic, and oxidative pathways. The aim of this study is to evaluate initially the biocompatibility of LTUs and their degradation products. Studies involving primary dermal human fibroblasts cultured in contact with LTU films or degradation products suggest a lack of toxicity (cell viabilities >93% with p < 0.05 compared to the control for all studies). The diversity of LTU polymer chemistry and the ability of LTUs to phase separate seem to present a heterogeneous surface with variable wettability. This phenomenon influences the adhesion and proliferation of human fibroblasts on polymeric surfaces, wherein fibroblast adhesion on polycaprolactone diol (PCL) based LTUs is characterized by higher cell counts (81,250 ± 18,390 for PCL-C-DTH (desaminotyrosine-tyrosyl hexyl, DTH), 58,360 ± 7370 for PCL-L-DTH, 38,480 ± 12,680 for PEG-C-DTH (polyethylene glycol, PEG), and 46,430 ± 16,000 for PEG-L-DTH at 120 h with p < 0.001 for comparison between PCL-C-DTH and all other LTUs), more rapid cellular proliferation (doubling time of 37-49 h for PCL-based LTUs compared to 68-90 h for PEG-based LTUs), and a uniform cell distribution compared to PEG-based LTUs. However, immunofluorescence assay for F-actin suggests that the cells are well attached. Thus, the lack of cytotoxicity and the ability to control cellular adhesion through polymer chemistry make LTUs attractive candidates for tissue-engineering applications that require elastomeric, biodegradable, and biocompatible polymers.


Assuntos
Materiais Biocompatíveis/química , Poliuretanos/química , Tirosina/química , Actinas/metabolismo , Materiais Biocompatíveis/toxicidade , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Teste de Materiais , Poliuretanos/toxicidade , Engenharia Tecidual
14.
ChemSusChem ; 6(12): 2281-9, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24227502

RESUMO

The conversion of lignocellulose is a crucial topic in the renewable and sustainable chemical industry. However, cellulose from lignocellulose is not soluble in polar solvents, and is, therefore, difficult to convert into value-added chemicals. A strategy to overcome this drawback is the use of mesoporous carbon, which enhances the affinity between the cellulose and the catalyst through its abundant functional groups and large uniform pores. Herein, we report on the preparation of a Pt catalyst supported on a type of 3D mesoporous carbon inspired by Echinometra mathae (Pt/CNE) to enhance the interaction between the catalyst and a nonsoluble reactant. In the hydrolytic hydrogenation of cellulose, the abundant oxygen groups of CNE facilitated the access of cellulose to the surface of the catalyst, and the open pore structure permits cello-oligomers to effectively diffuse to the active sites inside the pore. The highly dispersed Pt performed dual roles: hydrolysis by in situ generating protons from H2 or water as well as effective hydrogenation. The use of the Pt/CNE catalyst resulted in an approximately 80 % yield of hexitol, the best performance reported to date. In direct conversion of hardwood powder, the Pt/CNE shows good performance in the production of sugar alcohols (23 % yield). We expect that the open-structured 3D carbon will be widely applied to the conversion of various lignocellulosic materials.


Assuntos
Carbono/química , Lignina/química , Nanopartículas Metálicas/química , Platina/química , Álcoois Açúcares/química , Catálise , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Porosidade
15.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 48(10): 596-9, 2013 Oct.
Artigo em Zh | MEDLINE | ID: mdl-24438566

RESUMO

OBJECTIVE: To evaluate the treatment time and the anterior and posterior teeth movement pattern as closing extraction space for the Class III surgical patients facilitated by accelerated osteogenic orthodontic treatment. METHODS: There were 10 skeletal Class III patients in accelerated osteogenic orthodontic group (AOO) and 10 patients in control group. Upper first premolars were extracted in all patients. After leveling and alignment (T2), corticotomy was performed in the area of maxillary anterior teeth to accelerate space closing.Study models of upper dentition were taken before orthodontic treatment (T1) and after space closing (T3). All the casts were laser scanned, and the distances of the movement of incisors and molars were digitally measured. The distances of tooth movement in two groups were recorded and analyzed. RESULTS: The alignment time between two groups was not statistically significant. The treatment time in AOO group from T2 to T3 was less than that in the control group (less than 9.1 ± 4.1 months). The treatment time in AOO group from T1 to T3 was less than that in the control group (less than 6.3 ± 4.8 months), and the differences were significant (P < 0.01). Average distances of upper incisor movement (D1) in AOO group and control group were (2.89 ± 1.48) and (3.10 ± 0.95) mm, respectively. Average distances of upper first molar movement (D2) in AOO group and control group were (2.17 ± 1.13) and (2.45 ± 1.04) mm, respectively.No statistically significant difference was found between the two groups (P > 0.05). CONCLUSIONS: Accelerated osteogenic orthodontic treatment could accelerate space closing in Class III surgical patients and shorten preoperative orthodontic time. There were no influence on the movement pattern of anterior and posterior teeth during pre-surgical orthodontic treatment.


Assuntos
Má Oclusão Classe III de Angle/cirurgia , Ortodontia Corretiva/métodos , Osteotomia/métodos , Adolescente , Adulto , Fosfatos de Cálcio/uso terapêutico , Cefalometria , Feminino , Humanos , Masculino , Maxila/cirurgia , Dente Molar/cirurgia , Estudos Prospectivos , Técnicas de Movimentação Dentária , Adulto Jovem
16.
Int J Biol Macromol ; 50(3): 530-3, 2012 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-22289862

RESUMO

Several important monolignols such as coniferyl alcohol were catalyzed using Rhus laccase (RL) from Rhus vernicifera in a water/acetone solution. The enzymatic mechanism is discussed in detail. Sites 6, ß, and phenolic oxygen were the main active sites of phenylpropanoid compounds, which were first oxidized by the enzyme and then radicalized. RL was also responsible for lignin biosynthesis, especially in the early stage.


Assuntos
Lacase/metabolismo , Fenóis/metabolismo , Rhus/enzimologia , Água/química , Biotransformação , Lignina/metabolismo , Soluções
17.
Colloids Surf B Biointerfaces ; 75(1): 115-22, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19744840

RESUMO

A surface with a density gradient of poly(ethylene glycol) (PEG) is an attractive substrate for combinatorial studies of biological phenomena. In this study, the generation of discrete step-wise density gradients of PEG utilizing a contact-printing approach is reported. The step-wise gradient template is achieved by contact-printing n-octadecyltrichlorosilane (OTS) to a glass from a hemispherical elastomeric stamp when the stamp is brought into contact with the substrate, and then step-wisely increasing the contact area as the corresponding contact-printing time for the step decreases. A PEG-silane is then used to backfill the unoccupied spaces of the contact printed OTS gradient to generate the OTS-PEG density gradient. Various characterizations, including water contact angle measurement, lateral force microscopy, and X-ray photoelectron spectroscopy, are conducted and confirmed that the surface coverage of OTS increases (or the coverage of PEG decreases) with the increase of contact-printing time of OTS. The step-wise gradient is illustrated by adsorption of a bovine serum albumin labeled with fluorescein isothiocyanate and subsequent attachment of fibroblasts. The amounts of protein adsorption and cellular attachment increase with the decrease of the surface coverage of PEG.


Assuntos
Teste de Materiais/métodos , Tamanho da Partícula , Polietilenoglicóis/química , Adsorção , Animais , Bovinos , Adesão Celular , Células Cultivadas , Fibroblastos/citologia , Fluoresceína-5-Isotiocianato/metabolismo , Fricção , Vidro/química , Humanos , Microscopia de Fluorescência , Espectroscopia Fotoeletrônica , Soroalbumina Bovina/metabolismo , Silanos/química , Propriedades de Superfície , Água/química
18.
Int J Pharm ; 368(1-2): 199-206, 2009 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-19026734

RESUMO

Current delivery devices for drugs and genes such as films and microspheres are usually formulated from polymers that degrade over a period of months. In general, these delivery systems are designed to achieve an extracellular release of their encapsulated drugs. For drugs that require interaction with cellular machinery, the efficacies of both macroscopic and microscopic delivery systems are normally low. In contrast, nano-sized drug delivery vehicles could achieve high delivery efficiencies, but they must degrade quickly, and the delivery system itself should be nontoxic to cells. In this aspect, biodegradable nanospheres formulated from l-tyrosine polyphosphate (LTP) have been produced from an emulsion of oil and water for the potential use as an intracellular delivery device. Scanning electron microscopy (SEM) and dynamic laser light scattering (DLS) show that LTP nanospheres possess a diameter range between 100 and 600 nm. SEM reveals nanospheres formulated from LTP are spherical and smooth. Additionally, DLS studies demonstrate that nanospheres degrade hydrolytically in 7 days. Confocal microscopy reveals LTP nanospheres are internalized within human fibroblasts. Finally, the cell viability after exposure to LTP nanospheres and determined with a LIVE/DEAD Cell Viability Assay is comparable to a buffer control. In conclusion, our nanospheres have been shown to be nontoxic to human cells, possess the appropriate size for endocytosis by human cells, and degrade within 7 days. Therefore LTP nanospheres can be used for a sustained intracellular delivery device.


Assuntos
Portadores de Fármacos/química , Organofosfatos/síntese química , Polímeros/síntese química , Tirosina/química , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/toxicidade , Composição de Medicamentos , Emulsões , Fibroblastos/metabolismo , Humanos , Lasers , Microscopia Confocal , Microscopia Eletrônica de Varredura , Nanosferas , Organofosfatos/administração & dosagem , Organofosfatos/toxicidade , Tamanho da Partícula , Polímeros/administração & dosagem , Polímeros/toxicidade , Propriedades de Superfície , Tirosina/administração & dosagem , Tirosina/toxicidade
19.
Mol Pharm ; 6(3): 986-95, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19341289

RESUMO

Currently, viruses are utilized as vectors for gene therapy, since they transport across cellular membranes, escape endosomes, and effectively deliver genes to the nucleus. The disadvantage of using viruses for gene therapy is their immune response. Therefore, nanospheres have been formulated as a nonviral gene vector by blending l-tyrosine-polyphosphate (LTP) with polyethylene glycol grafted to chitosan (PEG-g-CHN) and linear polyethylenimine (LPEI) conjugated to plasmid DNA (pDNA). PEG-g-CHN stabilizes the emulsion and prevents nanosphere coalescence. LPEI protects pDNA degradation during nanosphere formation, provides endosomal escape, and enhances gene expression. Previous studies show that LTP degrades within seven days and is appropriate for intracellular gene delivery. These nanospheres prepared by water-oil emulsion by sonication and solvent evaporation show diameters between 100 and 600 nm. Also, dynamic laser light scattering shows that nanospheres completely degrade after seven days. The sustained release of pDNA and pDNA-LPEI polyplexes is confirmed through electrophoresis and PicoGreen assay. A LIVE/DEAD cell viability assay shows that nanosphere viability is comparable to that of buffers. X-Gal staining shows a sustained transfection for 11 days using human fibroblasts. This result is sustained longer than pDNA-LPEI and pDNA-FuGENE 6 complexes. Therefore, LTP-pDNA nanospheres exhibit controlled transfection and can be used as a nonviral gene delivery vector.


Assuntos
Nanopartículas/química , Nanosferas/química , Polímeros/química , Transfecção/métodos , Tirosina/química , Sobrevivência Celular , Quitosana/química , Eletroforese em Gel de Ágar , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Polietilenoglicóis/química , Polietilenoimina/química
20.
Biomaterials ; 30(22): 3771-9, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19395021

RESUMO

The pressing need to treat multi-drug resistant bacteria in the chronically infected lungs of cystic fibrosis (CF) patients has given rise to novel nebulized antimicrobials. We have synthesized a silver-carbene complex (SCC10) active against a variety of bacterial strains associated with CF and chronic lung infections. Our studies have demonstrated that SCC10-loaded into L-tyrosine polyphosphate nanoparticles (LTP NPs) exhibits excellent antimicrobial activity in vitro and in vivo against the CF relevant bacteria Pseudomonas aeruginosa. Encapsulation of SCC10 in LTP NPs provides sustained release of the antimicrobial over the course of several days translating into efficacious results in vivo with only two administered doses over a 72 h period.


Assuntos
Anti-Infecciosos , Nanopartículas , Organofosfatos , Polímeros , Pseudomonas aeruginosa/efeitos dos fármacos , Infecções Respiratórias/tratamento farmacológico , Prata , Administração por Inalação , Animais , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/uso terapêutico , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Fibrose Cística/tratamento farmacológico , Fibrose Cística/microbiologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Humanos , Masculino , Teste de Materiais , Metano/análogos & derivados , Metano/química , Metano/farmacologia , Metano/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Testes de Sensibilidade Microbiana , Estrutura Molecular , Nanopartículas/química , Nanopartículas/uso terapêutico , Nebulizadores e Vaporizadores , Organofosfatos/química , Organofosfatos/metabolismo , Tamanho da Partícula , Polímeros/química , Polímeros/metabolismo , Infecções Respiratórias/microbiologia , Prata/química , Prata/farmacologia , Prata/uso terapêutico
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