Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
J Biomater Sci Polym Ed ; 32(7): 874-885, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33570467

RESUMO

The patients with chronic pain in osteoarthritis often have insufficient pain relief from non-opioids analgesics. Buprenorphine is a promising molecule for symptomatic relief of chronic pain. The marketed parenteral injections and sublingual tablets have short duration of action (half-life = 2.7 h), which is not suitable to manage chronic pain. The purpose of this research was to design buprenorphine-loaded Pluronic F127-reduced graphene oxide transdermal (noninvasive) hydrogel to achieve sustained release of buprenorphine to manage chronic pain in osteoarthritis. Pluronic F127 was used to stabilize the reduced graphene oxide in hydrogel system. The characterization studies including Fourier transform infrared spectroscopy, X-ray diffraction, and Raman spectroscopy confirmed the synthesis of Pluronic F127-reduced graphene oxide from graphite. The transmission electron microscopy image showed flat nanosheets of reduced graphene oxide (rGO). The developed hydrogel showed desirable pH, viscosity, adhesiveness, hardness, and cohesiveness for transdermal application. The ex vivo release study demonstrated the ability of the Pluronic F127-reduced graphene oxide (P-rGO) hydrogel to prolong release up to 14 days, owing to the strong π-π interactions between the graphene oxide (GO) and the buprenorphine. In cold ethanol tail flick model, the GO hydrogel showed sustained analgesic effect in comparison with hydrogel without rGO. Thus, this study demonstrated the potential of using Pluronic F127-reduced graphene oxide nanocarriers to prolong local analgesia for effective management for chronic pain.


Assuntos
Buprenorfina , Grafite , Osteoartrite , Humanos , Hidrogéis
2.
Braz. J. Pharm. Sci. (Online) ; 56: e18638, 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1249165

RESUMO

This study aimed to analyze the antiarthritic activity of ginkgolic acid against the Complete Freund's Adjuvant (CFA)-induced arthritis in rats. Arthritis was induced through an intradermal injection of CFA (0.1 mL) at the right hind footpad of adult Wistar Albino rats. Ginkgolic acid was administered orally at doses of 25 mg/kg and 50 mg/kg, respectively, once daily via gavage for 25 days upon inducing arthritis. Indomethacin was administered orally at a dose of 3 mg/kg twice in a week which served as positive control group. The animals were sacrificed and subjected to biochemical and histopathological analysis upon completion of treatment. Ginkgolic acid was able to reverse the arthritic effect (p < 0.01) induced by CFA in a dose dependent manner. Swelling of paw, thymus and spleen index, serum biomarker levels, and pro-inflammatory cytokines were significantly reduced (p < 0.01) by the acid whereas the antioxidant enzyme activities were remarkably restored. The histopathological findings were in agreement with the biochemical results. The results indicate that the antioxidant and anti-inflammatory properties of ginkgolic acid can be credited to the antiarthritic effects, and it can be promoted as a potential agent for therapeutic use against osteoarthritis


Assuntos
Animais , Masculino , Ratos , Artrite Experimental/induzido quimicamente , Adjuvante de Freund/agonistas , Osteoartrite/patologia , Injeções Intradérmicas , Indometacina , Antioxidantes/classificação
3.
J Synchrotron Radiat ; 24(Pt 3): 699-706, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28452764

RESUMO

Information on the structural evolution of materials under high pressure is of great importance for understanding the properties of materials exhibited under high pressure. High-pressure powder diffraction is widely used to investigate the structure evolution of materials at such pressure. Unfortunately, powder diffraction data are usually insufficient for retrieving the atomic structures, with high-pressure single-crystal diffraction being more desirable for such a purpose. Here, a high-pressure single-crystal diffraction experimental system developed recently at beamline 4W2 of Beijing Synchrotron Radiation Facility (BSRF) is reported. The design and operation of this system are described with emphasis on special measures taken to allow for the special circumstance of high-pressure single-crystal diffraction. As an illustration, a series of diffraction datasets were collected on a single crystal of LaB6 using this system under various pressures (from ambient pressure to 39.1 GPa). The quality of the datasets was found to be sufficient for structure solution and subsequent refinement.

4.
PeerJ ; 4: e1953, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27123381

RESUMO

Background. The decline of submerged plant populations due to high heavy metal (e.g., Cu) levels in sediments and ammonia nitrogen (ammonia-N) accumulation in the freshwater column has become a significant global problem. Previous studies have evaluated the effect of ammonia-N on submerged macrophytes, but few have focused on the influence of sediment Cu on submerged macrophytes and their combined effects. Methods. In this paper, we selected three levels of ammonia-N (0, 3, and 6 mg L(-1)) and sediment Cu (25.75 ± 6.02 as the control, 125.75 ± 6.02, and 225.75 ± 6.02 mg kg(-1)), to investigate the influence of sediment Cu and ammonia-N on submerged Vallisneria natans. We measured the relative growth rate (RGR), above- and below- ground biomass, chlorophyll, non-protein thiol (NP-SH), and free proline. Results and Discussion. The below-ground biomass of V. natans decreased with increasing Cu sediment levels, suggesting that excessive sediment Cu can result in significant damage to the root of V. natans. Similarly, the above-ground biomass significantly decreased with increasing ammonia-N concentrations, indicating that excessive water ammonia-N can cause significant toxicity to the leaf of V. natans. In addition, high ammonia-N levels place a greater stress on submerged plants than sediment Cu, which is indicated by the decline of RGR and chlorophyll, and the increase of (NP-SH) and free proline. Furthermore, high sediment Cu causes ammonia-N to impose greater injury on submerged plants, and higher sediment Cu levels (Cu ≥ 125.75 mg kg(-1)) led to the tolerant values of ammonia-N for V. natans decreasing from 6 to 3 mg L(-1). This study suggests that high sediment Cu restricts the growth of plants and intensifies ammonia-N damage to V. natans.

5.
Nat Commun ; 6: 5703, 2015 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-25641091

RESUMO

The polyamorphsim in amorphous materials is one of the most fascinating topics in condensed matter physics. In amorphous metals, the nature of polyamorphic transformation is poorly understood. Here we investigate the structural evolution of a Ce-based metallic glass (MG) with pressure at room temperature (RT) and near the glass transition temperature by synchrotron X-ray diffraction, uncovering novel behaviours. The MG shows hierarchical densification processes at both temperatures, arising from the hierarchy of interatomic interactions. In contrast with a continuous and smooth process for the low- to medium-density amorphous state transformation at RT, a relatively abrupt and discontinuous transformation around 5.5 GPa is observed at 390 K, suggesting a possible weak first-order nature. Furthermore, both positive and abnormal-negative thermal expansion behaviours on medium-range order are observed in different pressure windows, which could be related to the low-energy vibrational motions and relaxation of the weakly linked solute-centred clusters.

6.
Tissue Eng Part A ; 21(3-4): 603-15, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25273546

RESUMO

Cell-based therapies are major focus of current research for treatment of liver diseases. In this study, mesenchymal stem cells were isolated from human umbilical cord Wharton's jelly (WJ-MSCs). Results confirmed that WJ-MSCs isolated in this study could express the typical MSC-specific markers and be induced to differentiate into adipocytes, osteoblasts, and chondrocytes. They could also be induced to differentiate into hepatocyte-like cells. Poly (3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (PHBVHHx) is a new member of polyhydroxyalkanoate family and biodegradable polyester produced by bacteria. PHBVHHx scaffolds showed much higher cell attachment and viability than the other polymers tested. PHBVHHx scaffolds loaded with WJ-MSCs were transplanted into liver-injured mice. Liver morphology improved after 30 days of transplantation and looked similar to normal liver. Concentrations of serum alanine aminotransferase and total bilirubin were significantly lower, and albumin was significantly higher on days 14 and 30 in the WJ-MSCs+scaffold group than in the carbon tetrachloride (CCl4) group. Hematoxylin-eosin staining showed that liver had similar structure of normal liver lobules and similar size and shape of normal hepatic cells, and Masson staining demonstrated that liver had less blue staining for collagen after 30 days of transplantation. Real-time reverse transcription-polymerase chain reaction (RT-PCR) showed that the expression of the bile duct epithelial cell gene CK-19 in mouse liver is significantly lower on days 14 and 30 in the WJ-MSCs+scaffold group than in the CCl4 group. Real-time RT-PCR, immunocytochemistry, and periodic acid-Schiff staining showed that WJ-MSCs in scaffolds differentiated into hepatocyte-like cells on days 14 and 30 in the WJ-MSCs+scaffold group. Real-time RT-PCR also demonstrated that WJ-MSCs in scaffolds expressed endothelial cell genes Flk-1, vWF, and VE-cadherin on days 14 and 30 in the WJ-MSCs+scaffold group, indicating that WJ-MSCs also differentiated into endothelial-like cells. These results demonstrated that PHBVHHx scaffolds loaded with WJ-MSCs significantly promoted the recovery of injured liver and could be further studied for liver tissue engineering.


Assuntos
Ácido 3-Hidroxibutírico/química , Caproatos/química , Transplante de Células-Tronco de Sangue do Cordão Umbilical/instrumentação , Hepatopatias/patologia , Hepatopatias/terapia , Regeneração Hepática/fisiologia , Tecidos Suporte , Animais , Materiais Biocompatíveis/síntese química , Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Hepatopatias/fisiopatologia , Teste de Materiais , Células-Tronco Mesenquimais/citologia , Camundongos , Poliésteres , Recuperação de Função Fisiológica/fisiologia , Engenharia Tecidual/instrumentação , Resultado do Tratamento
7.
Mater Sci Eng C Mater Biol Appl ; 45: 374-82, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25491842

RESUMO

More attention has recently been focused on the treatment of various kinds of hepatic diseases based on cell-based therapies. In this study, mesenchymal stem cells were isolated from umbilical cord (UC-MSCs). Results confirmed that UC-MSCs could differentiate into adipocytes, osteoblasts and hepatocytes. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (PHBVHHx), a new member of polyhydroxyalkanoate (PHA) family, was produced by bacteria. Liver-injured mouse model was established by CCl4 injection. PHBVHHx scaffolds were transplanted into the liver-injured mice. Liver morphology on day 28 post-transplantation of scaffolds loaded with UC-MSCs or hepatocyte-like cells differentiated from UC-MSCs significantly improved and looked similar to the normal liver. Concentrations of albumin (ALB) significantly increased, and total bilirubin (TB) and alanine axminotransferase (ALT) significantly decreased on days 14 and 28 post-transplantation of scaffolds loaded with UC-MSCs or differentiated UC-MSCs. HE staining showed that on day 28 post-transplantation of scaffolds loaded with UC-MSCs or differentiated UC-MSCs, livers had similar tissue structure of normal livers. Masson staining showed that on day 28 post-transplantation of scaffolds loaded with UC-MSCs or differentiated UC-MSCs, livers had less blue staining for collagen deposition compared with the others. These results demonstrated that PHBVHHx scaffolds loaded with UC-MSCs or differentiated UC-MSCs had the similar effect on injured livers and significantly promoted the recovery of injured livers.


Assuntos
Hepatócitos/citologia , Células-Tronco Mesenquimais/citologia , Engenharia Tecidual/métodos , Tecidos Suporte/química , Adipócitos/citologia , Albuminas/metabolismo , Animais , Bilirrubina/metabolismo , Diferenciação Celular , Modelos Animais de Doenças , Fígado/fisiologia , Transplante de Células-Tronco Mesenquimais , Camundongos , Osteoblastos/citologia , Polímeros/química , Cordão Umbilical/citologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...