Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Langmuir ; 37(44): 13099-13106, 2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34705469

RESUMO

Multicompartment micelles (MCMs) attracted much attention since they have subdivided domains that could be employed to encapsulate and transport diverse compounds simultaneously. Usually, preparation of MCMs relied on precise synthesis of block copolymers (BCPs) and elegant control of assembly kinetics, making it difficult to successively produce MCMs. Herein, we report a facile yet effective method for preparing MCMs by adjusting the hydrodynamics in microfluidic channels. It was found that well-defined MCMs were formed through hydrodynamics-dependent secondary assembly in microfluidic chips. By adjusting the flow diffusion process by varying the flow rate ratio and total flow rate, both the internal structure and size of MCMs could be effectively changed. A product diagram of micellar morphologies associated to the initial polymer concentration and flow rate ratio of water/BCPs solution was constructed. More interestingly, quantum dots (QDs) could be selectively loaded into different domains of the MCMs. Consequently, the Förster resonance energy transfer among QDs could be effectively suppressed. Thus, the emission spectrum of MCMs/QDs hybrid particles could be easily tuned by changing the ratio of QDs, showing great potential application in photonics and sensors.


Assuntos
Micelas , Pontos Quânticos , Hidrodinâmica , Microfluídica , Polímeros
2.
Biochem Biophys Res Commun ; 519(2): 316-322, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31506175

RESUMO

Tilianin (TIL) may prevent and treat myocardial ischemia reperfusion injuries. However, its oral administration is hampered by its low bioavailability. The present study aimed to formulate lipid-polymer hybrid nanoparticles (LPHNs) as carriers for the sustained release and oral bioavailability enhancement of TIL in vitro and in vivo. A nanodrug delivery system of TIL-loaded LPHNs (TIL-LPHNs) was constructed. TIL-LPHNs were prepared via a self-assembly method, and their particle size, polymer dispersity index (PDI), zeta potential, encapsulation efficiency (EE) and morphology were investigated. In addition, pharmacokinetic studies were performed in vivo. The TIL-LPHN formulation produced a spherical, homogeneous, smooth surface and multi-lamellar structured nanoparticles. The particle size and distribution profile of TIL-LPHNs had a mean particle diameter of 54.6 ±â€¯5.3 nm and PDI of 0.112 ±â€¯0.017. The zeta potential was -33.4 ±â€¯4.7 mV. The EE of TIL-LPHNs was 86.6 ±â€¯3.6%, which was determined with the dialysis method. The TIL-LPHNs significantly enhanced the oral bioavailability of TIL with a 3.7-fold increase in the area under the concentration-time curve in comparison with the TIL solution. These findings support the potential use of LPHNs in improving the stability and bioavailability of TIL via oral administration.


Assuntos
Sistemas de Liberação de Medicamentos , Flavonoides/metabolismo , Glicosídeos/metabolismo , Lipídeos/química , Nanopartículas/química , Polímeros/química , Administração Oral , Animais , Disponibilidade Biológica , Liberação Controlada de Fármacos , Flavonoides/administração & dosagem , Flavonoides/farmacocinética , Glicosídeos/administração & dosagem , Glicosídeos/farmacocinética , Masculino , Ratos , Ratos Sprague-Dawley
3.
Int J Mol Sci ; 12(12): 9138-54, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22272124

RESUMO

Cis-9, trans-11 conjugated linoleic acid (c9, t11 CLA) producing bacteria have attracted much attention as novel probiotics which have shown beneficial effects on host health. However, bile salts are able to inhibit bacterial growth and c9, t11 CLA production. For recovering growth and c9, t11 CLA production of Lactobacillus acidophilus F0221 in the presence of bile salts, Tween series (Tween 20, Tween 40, Tween 60 and Tween 80) were added in growth culture containing 0.3% oxgall. Results showed that the viable counts were significantly (P < 0.05) recovered to 8.58-8.75 log CFU/mL in the presence of all Tween treatments. However, recovery of c9, t11 CLA production was only demonstrated in the presence of Tween 80 (72.89 µg/mL). Stepwise increasing oxgall in a concentrations range from 0.1% to 0.9% according to human intestinal physiological environments, Tween 80 still showed significant (P < 0.05) recovery ability on growth (8.91-8.04 log CFU/mL) and c9, t11 CLA (69.22-34.27 µg/mL) production. The effect of Tween 80 on growth and production was also investigated in the presence of different types of bile salts (sodium salts of cholic acid (CA), deoxycholic acid (DCA), chendeoxycholic acid (CDCA), glycocholic acid (GCA) and taurocholic acid (TCA)). Results showed that Tween 80 could significantly (P < 0.05) recover c9, t11 CLA production in the presence of all types of bile salts, but the Tween 80 could only significantly (P < 0.05) recover viable counts of the strain in the presence of CA, DCA and CDCA. This recovery ability could be attributed to the protection of leakage of intracellular material. Additionally, although bile salts inhibited growth and c9, t11 CLA production by the growing cell, it promoted the c9, t11 CLA production by the resting cell.


Assuntos
Ácidos e Sais Biliares/farmacologia , Proliferação de Células/efeitos dos fármacos , Lactobacillus acidophilus/efeitos dos fármacos , Ácidos Linoleicos Conjugados/biossíntese , Polissorbatos/farmacologia , Lactobacillus acidophilus/metabolismo , Lactobacillus acidophilus/fisiologia
4.
J Hazard Mater ; 162(1): 174-9, 2009 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-18579291

RESUMO

A composite inorganic polymer coagulant, polyferric aluminum chloride (PFAC) was prepared by using hydrochloric pickle liquor and calcium aluminate as main materials. The optimum conditions for preparing PFAC with the hydrochloric pickle liquor and the calcium aluminate were studied. The coagulation performance of PFAC was investigated by studying the turbidity, COD, total phosphate (TP) and NH(3)-N removal efficiency in municipal sewage treatment. Results indicated that the effective composition, basicity (simplified as B, B=[OH]/(3[Fe(T)+Al(T)])x100%), coagulation performance and stability of PFAC were affected by calcium aluminate dosage, reaction time, reaction temperature and stabilizing agents. The COD and turbidity removal efficiency of PFAC was better than that of PFS and FeCl(3), and the TP and NH(3)-N removal efficiency of PFAC was much better than that of PFS, FeCl(3) and PAC. PFAC not only possessed a good coagulation performance, but also had good stability when stored.


Assuntos
Compostos Férricos/química , Ácido Clorídrico/química , Metalurgia , Polímeros/química , Alumínio/química , Cloreto de Alumínio , Compostos de Alumínio/química , Fosfatos de Cálcio/química , Cloratos/química , Ferro/química , Nefelometria e Turbidimetria , Oxirredução , Esgotos/análise , Solubilidade , Temperatura
5.
ACS Appl Mater Interfaces ; 9(7): 6644-6651, 2017 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-28150931

RESUMO

Ultraflexible transparent film heaters have been fabricated by embedding conductive silver (Ag) nanowires into a thin poly(vinyl alcohol) film (AgNW/PVA). A cold-pressing method was used to rationally adjust the sheet resistance of the composite films and thus the heating powers of the AgNW/PVA film heaters at certain biases. The film heaters have a favorable optical transmittance (93.1% at 26 Ω/sq) and an outstanding mechanical flexibility (no visible change in sheet resistance after 10 000 bending cycles and at a radius of curvature ≤1 mm). The film heaters have an environmental endurance, and there is no significant performance degradation after being kept at high temperature (80 °C) and high humidity (45 °C, 80% humidity) for half a year. The efficient Joule heating can increase the temperature of the film heaters (20 Ω/sq) to 74 °C in ∼20 s at a bias of 5 V. The fast-heating characteristics at low voltages (a few volts) associated with its transparent and flexibility properties make the poly(dimethylsiloxane)/AgNW/PVA composite film a potential candidate in medical thermotherapy pads.


Assuntos
Nanofios , Condutividade Elétrica , Dureza , Temperatura Alta , Hipertermia Induzida , Membranas Artificiais , Oxirredução , Prata , Propriedades de Superfície
6.
Bioresour Technol ; 97(2): 257-64, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16171683

RESUMO

Resorcinol-tannin-formaldehyde copolymer resins (RTF) were prepared by using the bark extracts of Taiwan acacia (Acacia confusa) and China fir (Cunninghamia lanceolata) to substitute part of the resorcinol. From the results, the content of reactive phenolic materials in Taiwan acacia and China fir bark extracts were 51.6% and 46.5%, respectively. Aromatic compounds were the main components in the bark extracts showed by FT-IR analysis. The conventional synthesis condition used for RF resin was certainly not suitable for the RTF copolymer resin. It should be formed the novolak RF prepolymer by reacting the resorcinol with formaldehyde at the first stage, and then the bark extracts added and underwent the copolymerization reaction under acidic condition at the second-stage. The RTF copolymer resins prepared had cold-setting capability. They had higher viscosity, shorter gel time as compared with the RF resin. The RTF copolymer resins could be carried out the gluing application immediately after the hardener was added and had bonding strength the same as RF resin. But the RTF copolymer resins had worse stability and shorter shelf life than RF resin.


Assuntos
Acacia/química , Cunninghamia/química , Formaldeído/química , Casca de Planta/química , Resinas Vegetais/química , Resorcinóis/química , Taninos/química , Biopolímeros/química , Extratos Vegetais/química , Espectroscopia de Infravermelho com Transformada de Fourier , Taiwan , Viscosidade
7.
Korean J Orthod ; 46(3): 146-54, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27226960

RESUMO

OBJECTIVE: Different methods have been utilized to prevent enamel demineralization and other complications during orthodontic treatment. However, none of these methods can offer long-lasting and effective prevention of orthodontic complications or interventions after complications occur. Considering the photocatalytic effect of TiO2 on organic compounds, we hoped to synthesize a novel bracket with a TiO2 thin film to develop a photocatalytic antimicrobial effect. METHODS: The sol-gel dip coating method was used to prepare TiO2 thin films on ceramic bracket surfaces. Twenty groups of samples were composed according to the experimental parameters. Crystalline structure and surface morphology were characterized by X-ray diffraction and scanning electron microscopy, respectively; film thickness was examined with a surface ellipsometer. The photocatalytic properties under ultraviolet (UV) light irradiation were analyzed by evaluating the degradation ratio of methylene blue (MB) at a certain time. Antibacterial activities of selected thin films were also tested against Lactobacillus acidophilus and Candida albicans. RESULTS: Films with 5 coating layers annealed at 700℃ showed the greatest photocatalytic activity in terms of MB decomposition under UV light irradiation. TiO2 thin films with 5 coating layers annealed at 700℃ exhibited the greatest antimicrobial activity under UV-A light irradiation. CONCLUSIONS: These results provide promising guidance in prevention of demineralization by increasing antimicrobial activities of film coated brackets.

8.
Shanghai Kou Qiang Yi Xue ; 22(6): 618-22, 2013 Dec.
Artigo em Zh | MEDLINE | ID: mdl-24469121

RESUMO

PURPOSE: To explore the existence of lymphatic vessels in healthy human dental pulp. METHODS: Thirty healthy human dental pulps were obtained from non-carious premolars removed for orthodontic reasons. Immunohistochemistry was performed using the antibodies specific for lymphatic endothelium such as D2-40 and LYVE-1, and for vascular endothelial cell such as CD31 and CD34. The expression of D2-40 was detected by Western blotting and ultrastructure was examined by transmission electron microscopy. RESULTS: In healthy human dental pulps, we failed to detect any reactivity for the lymphatic markers D2-40 and LYVE-1 in the observed vessels. These vessels were positive stained by blood endothelial markers CD34 and CD31. Odontoblasts were weakly stained with D2-40. Western blotting performed on collagenase-treated human dental pulps did not show a band at 40 kDa, corresponding to the molecular weight of the lymphatic marker D2-40. Transmission electron microscopy indicated that vessels in dental pulp consisted of endothelial monolayer surrounded by pericytes and complete basement membrane, which were typical ultrastructural characteristics of blood vessels rather than lymphatic vessel. CONCLUSIONS: Human dental pulp does not contain true lymphatic vessels under healthy conditions. Whether lymphatic system is involved in dental pulp interstitial fluid circulation during inflammation deserved further study. Supported by National Natural Science Foundation of China (81100768) and Key Project Supported by Medical Science and Technology Development Foundation, Department of Health of Nanjing City (YKK11040 and QRX11123).


Assuntos
Polpa Dentária , Vasos Linfáticos , Dente Pré-Molar , Biomarcadores , Células Endoteliais , Endotélio Linfático , Humanos , Imuno-Histoquímica , Sistema Linfático
9.
J Pharm Biomed Anal ; 83: 129-34, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23739299

RESUMO

The polystyrene bead-based flow cytometric immunoassay has been widely reported. However, the preparation of functional polystyrene bead is still inconvenient. This study describes a simple and easy on-bacterium flow cytometric immunoassay for protein quantification, in which Staphylococcus aureus (SAC) is used as an antibody-antigen carrier to replace the polystyrene bead. The SAC beads were prepared by carboxyfluorescein diacetate succinimidyl ester (CFSE) labeling, paraformaldehyde fixation and antibody binding. Carcinoembryonic antigen (CEA) and cytokeratin-19 fragment (CYFRA 21-1) proteins were used as models in the test system. Using prepared SAC beads, biotinylated proteins, and streptavidin-phycoerythrin (SA-PE), the on-bacterium flow cytometric immunoassay was validated by quantifying CEA and CYFRA 21-1 in sample. Obtained data demonstrated a concordant result between the logarithm of the protein concentration and the logarithm of the PE mean fluorescence intensity (MFI). The limit of detection (LOD) in this immunoassay was at least 0.25 ng/ml. Precision and accuracy assessments appeared that either the relative standard deviation (R.S.D.) or the relative error (R.E.) was <10%. The comparison between this immunoassay and a polystyrene bead-based flow cytometric immunoassay showed a correlation coefficient of 0.998 for serum CEA or 0.996 for serum CYFRA 21-1. In conclusion, the on-bacterium flow cytometric immunoassay may be of use in the quantification of serum protein.


Assuntos
Citometria de Fluxo/métodos , Imunoensaio/métodos , Poliestirenos/efeitos adversos , Anticorpos/imunologia , Antígenos de Neoplasias/imunologia , Antígeno Carcinoembrionário/imunologia , Fluorescência , Queratina-19/imunologia , Sensibilidade e Especificidade , Staphylococcus aureus/metabolismo
10.
Shanghai Kou Qiang Yi Xue ; 14(2): 194-6, 2005 Apr.
Artigo em Zh | MEDLINE | ID: mdl-15886849

RESUMO

PURPOSE: To discuss the related problems of nursing during root canal preparation with nickel titanium mechanical instruments. METHODS: 206 cases were nursed who underwent root canal preparation, after which the dentists and patients were surveyed on their satisfactory extents, in order to assess the effect of nursing. RESULTS: The results of root canal preparation of 206 cases were good without any accidents such as break of instruments, while 100% dentists and 97.58% patients were satisfied with the nursing. CONCLUSION: Proper and skilled nursing could shorten treatment time, enhance patients' compliableness and decrease the unnecessary injuries. Thus it raised the efficiency and therapeutic effect.


Assuntos
Instrumentos Odontológicos , Níquel , Tratamento do Canal Radicular/enfermagem , Titânio , Humanos , Preparo de Canal Radicular/métodos , Tratamento do Canal Radicular/métodos
11.
Shanghai Kou Qiang Yi Xue ; 14(4): 427-30, 2005 Aug.
Artigo em Zh | MEDLINE | ID: mdl-16155713

RESUMO

PURPOSE: To evaluate the clinical effect of implant anchorage in the correction of malocclusion and restoration of dentition defects. METHODS: 14 cases who had Angle II malocclusion as well as dentition defects and whose molars could not serve as anchorage or who had no molars at all were selected. Implants in the maxilla or mandible were served first as anchorage to correct the malocclusion and then to restore the dentition defects. RESULTS: The implant anchorage in the palate didn't move medially after the anterior teeth had been adducted by 6-8 mm. 3 cases of zygo-alveolar ridge implantation failed. 5 cases of adult Angle II division I, II malocclusions as well as Kennedy II dentition defects were orthodontically treated for 8-10 months, the lower anterior teeth were adducted by 6-8mm, aligned and the midline was corrected with no medial movement of the implant anchorage. Then the implants were used to restore the missing teeth. CONCLUSION: It is feasible and effective to use implant as anchorage in orthodontic and prosthodontic treatment in cases without available anchorage.


Assuntos
Implantação Dentária Endóssea , Implantes Dentários , Má Oclusão/cirurgia , Prostodontia , Humanos , Mandíbula , Maxila , Dente Molar
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA