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1.
Nanoscale ; 11(27): 12965-12972, 2019 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-31259344

RESUMO

With the wide application of Stöber silica nanoparticles and their ability to access the brain, it is crucial to evaluate their neurotoxicity. In this study, we used three in vitro model cells, i.e., N9, bEnd.3 and HT22 cells, representing microglia, microendothelial cells and neurons, respectively, to assess the neurotoxicity of Stöber silica nanoparticles with different sizes. We found that Stöber silica nanoparticles almost had no effect on the viability of bEnd.3 and HT22 cells. In contrast, they induced size-dependent toxicity in N9 cells, which represent the residential macrophages of the central nervous system. Further mechanistic study demonstrated that the toxicity in N9 cells was related to their surface silanol display. In addition, we demonstrated that Stöber silica nanoparticles induced the production of mitochondrial ROS, release of IL-1ß, cleavage of GSDMD, and occurrence of pyroptosis in N9 cells. Features of pyroptosis were also observed in primary microglia and macrophage J774A.1. In conclusion, these findings were helpful for the safety consideration of Stöber silica nanoparticles considering their wide applications in our daily life.


Assuntos
Microglia/metabolismo , Mitocôndrias/metabolismo , Nanopartículas/efeitos adversos , Piroptose/efeitos dos fármacos , Dióxido de Silício/efeitos adversos , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos , Microglia/patologia , Mitocôndrias/patologia , Nanopartículas/química , Espécies Reativas de Oxigênio/metabolismo , Dióxido de Silício/química , Dióxido de Silício/farmacologia
2.
Int J Nanomedicine ; 14: 4167-4186, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31239675

RESUMO

Engineered nanomaterials (ENMs) have been widely used in various fields due to their novel physicochemical properties. However, the use of ENMs has led to an increased exposure in humans, and the safety of ENMs has attracted much attention. It is universally acknowledged that ENMs could enter the human body via different routes, eg, inhalation, skin contact, and intravenous injection. Studies have proven that ENMs can cross or bypass the blood-brain barrier and then access the central nervous system and cause neurotoxicity. Until now, diverse in vivo and in vitro models have been developed to evaluate the neurotoxicity of ENMs, and oxidative stress, inflammation, DNA damage, and cell death have been identified as being involved. However, due to various physicochemical properties of ENMs and diverse study models in existing studies, it remains challenging to establish the structure-activity relationship of nanomaterials in neurotoxicity. In this paper, we aimed to review current studies on ENM-induced neurotoxicity, with an emphasis on the molecular and cellular mechanisms involved. We hope to provide a rational material design strategy for ENMs when they are applied in biomedical or other engineering applications.


Assuntos
Nanoestruturas/toxicidade , Nanotecnologia , Neurotoxinas/toxicidade , Morte Celular/efeitos dos fármacos , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/patologia , Dano ao DNA , Humanos , Nanoestruturas/química
3.
Vaccine ; 37(24): 3167-3178, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31047671

RESUMO

In conjugate, inactivated, recombinant, and toxoid vaccines, adjuvants are extensively and essentially used for enhanced and long-lasting protective immune responses. Depending on the type of diseases and immune responses required, adjuvants with different design strategies are developed. With aluminum salt-based adjuvants as the most used ones in commercial vaccines, other limited adjuvants, e.g., AS01, AS03, AS04, CpG ODN, and MF59, are used in FDA-approved vaccines for human use. In this paper, we review the uses of different adjuvants in vaccines including the ones used in FDA-approved vaccines and vaccines under clinical investigations. We discuss how adjuvants with different formulations could affect the magnitude and quality of adaptive immune response for optimized protection against specific pathogens. We emphasize the molecular mechanisms of various adjuvants, with the aim to establish structure-activity relationships (SARs) for designing more effective and safer adjuvants for both preventative and therapeutic vaccines.

4.
Mater Sci Eng C Mater Biol Appl ; 93: 890-901, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30274126

RESUMO

Neural stem cells (NSCs), as a self-renewing and multipotent cell population, have been widely studied for never regeneration. Engineering scaffold is one of the important factors to regulate NSCs proliferation and differentiation towards the formation of the desired cells and tissues. Because neural cells are electro-active ones, a conductive scaffold is required to provide three-dimensional cell growth microenvironments and appropriate synergistic cell guidance cues. In this study, a poly (3,4­ethylenedioxythiophene)/chitosan/gelatin (PEDOT/Cs/Gel) scaffold was prepared via in situ interfacial polymerization, with a nanostructured layer of PEDOT assembling on the channel surface of porous Cs/Gel scaffold. This electrically conductive, three-dimensional, porous and biodegradable PEDOT/Cs/Gel scaffold was used as a novel scaffold for NSCs three-dimension (3D) culture in vitro. It was found that the layer of PEDOT on the channel surface of Cs/Gel scaffolds could greatly promote NSCs adhesion and proliferation. Additionally, under the differentiation condition, the protein and gene analysis suggested that PEDOT/Cs/Gel scaffolds could significantly enhance the NSCs differentiation towards neurons and astrocytes with the up-regulation of ß tubulin-III and GFAP expression. In conclusion, these results demonstrated that the PEDOT/Cs/Gel scaffolds as an electrically conductive scaffold could not only promote NSCs adhesion and proliferation but also enhance NSCs differentiation into neurons and astrocytes with higher protein and gene expression. PEDOT-assembled Cs/Gel scaffold will be a promising conductive substrate for NSCs research and neural tissue engineering.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/química , Quitosana/química , Gelatina/química , Tecido Nervoso/metabolismo , Células-Tronco Neurais/metabolismo , Polímeros/química , Engenharia Tecidual , Tecidos Suporte/química , Animais , Técnicas de Cultura de Células/métodos , Tecido Nervoso/citologia , Células-Tronco Neurais/citologia , Ratos , Ratos Sprague-Dawley
5.
Mater Sci Eng C Mater Biol Appl ; 84: 32-43, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29519441

RESUMO

Electroconductive hydrogels with excellent electromechanical properties have become crucial for biomedical applications. In this study, we developed a conductive composite hydrogel via in-situ chemical polymerization based on carboxymethyl chitosan (CMCS), as a biodegradable base macromolecular network, and poly(3,4-ethylenedioxythiophene) (PEDOT), as a conductive polymer layer. The physicochemical and electrochemical properties of conductive hydrogels (PEDOT/CMCS) with different contents of PEDOT polymer were analyzed. Cell viability and proliferation of neuron-like rat phaeochromocytoma (PC12) cells on these three-dimensional conductive hydrogels were evaluated in vitro. As results, the prepared semi-interpenetrating network hydrogels were shown to consist of up to 1825±135wt% of water with a compressive modulus of 9.59±0.49kPa, a porosity of 93.95±1.03% and an electrical conductivity of (4.68±0.28)×10-3S·cm-1. Cell experiments confirmed that PEDOT/CMCS hydrogels not only had no cytotoxicity, but also supported cell adhesion, viability and proliferation. These results demonstrated that the incorporation of conductive PEDOT component into CMCS hydrogels endowed the hydrogels with enhanced mechanical strength, conductivity and kept the biocompatibility. Thus, the attractive performances of these composite hydrogels would make them suitable for further neural tissue engineering application, such as nerve regeneration scaffold materials.


Assuntos
Materiais Biocompatíveis/química , Compostos Bicíclicos Heterocíclicos com Pontes/química , Quitosana/análogos & derivados , Hidrogéis/química , Polímeros/química , Engenharia Tecidual , Animais , Materiais Biocompatíveis/farmacologia , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quitosana/química , Condutividade Elétrica , Hidrogéis/farmacologia , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Células PC12 , Porosidade , Ratos , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Int J Biol Macromol ; 109: 1-11, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29222020

RESUMO

Excessive free radicals can cause oxidative damage to human tissues, which results in a variety of diseases. Therefore, the development of antioxidant materials is one of the great projects in biomedical field. In this work, antioxidant protocatechuic acid (PCA) monomers were grafted onto chitosan (CS) backbones to develop a PCA grafted chitosan (PCA-g-CS) antioxidant copolymer via the method of free radical-induced grafting reaction. The formation of covalent bonds between PCA and CS were confirmed by FTIR, 1H NMR, XRD and UV-vis. The antioxidant activity of PCA-g-CS was analyzed by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical scavenging assays. In addition, the cytotoxicity of PCA-g-CS on neuron-like rat phaeochromocytoma (PC12) cells was evaluated by using MTT assay. The neuroprotective effects against hydrogen peroxide (H2O2) and l-glutamic acid (GLU) induced apoptosis in PC12 cells were also investigated. Our results demonstrated that the PCA-g-CS antioxidant copolymer had the ability to scavenge DPPH and hydroxyl radical in vitro. Furthermore, the PCA-g-CS was biocompatible and had neuroprotective effects against free radical-induced apoptosis in PC12 cells. This PCA-g-CS copolymer is firstly synthesized for neuroprotection and the results suggest the PCA-g-CS may be a potential antioxidant material in the treatment of oxidative damage related diseases.


Assuntos
Quitosana/química , Hidroxibenzoatos/química , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Polímeros/química , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Quitosana/síntese química , Quitosana/farmacologia , Estrutura Molecular , Fármacos Neuroprotetores/síntese química , Polímeros/síntese química , Polímeros/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Relação Estrutura-Atividade , Difração de Raios X
7.
ACS Appl Mater Interfaces ; 9(51): 44911-44921, 2017 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-29214806

RESUMO

Self-propelled droplet jumping on nanostructured superhydrophobic surfaces is of interest for a variety of industrial applications including self-cleaning, water harvesting, power generation, and thermal management systems. However, the uncontrolled nucleation-induced Wenzel state of condensed droplets at large surface subcooling (high heat flux) leads to the formation of unwanted large pinned droplets, which results in the flooding phenomenon and greatly degrades the heat transfer performance. In this work, we present a novel strategy to manipulate droplet behaviors during the process from the droplet nucleation to growth and departure through a combination of spatially controlling initial nucleation for mobile droplets by closely spaced nanowires and promoting the spontaneous outward movement of droplets for rapid removal using micropatterned nanowire arrays. Through the optical visualization experiments and heat transfer tests, we demonstrate greatly improved condensation heat transfer characteristics on the hierarchical superhydrophobic surface including the higher density of microdroplets, smaller droplet departure radius, 133% wider range of surface subcooling for droplet jumping, and 37% enhancement in critical heat flux for jumping droplet condensation, compared to the-state-of-art jumping droplet condensation on nanostructured superhydrophobic surfaces. The excellent water repellency of such hierarchical superhydrophobic surfaces can be promising for many potential applications, such as anti-icing, antifogging, water desalination, and phase-change heat transfer.

8.
Biomater Sci ; 5(10): 2024-2034, 2017 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-28894864

RESUMO

Engineering scaffolds with excellent electro-activity is increasingly important in tissue engineering and regenerative medicine. Herein, conductive poly(3,4-ethylenedioxythiophene) doped with hyaluronic acid (PEDOT-HA) nanoparticles were firstly synthesized via chemical oxidant polymerization. A three-dimensional (3D) PEDOT-HA/Cs/Gel scaffold was then developed by introducing PEDOT-HA nanoparticles into a chitosan/gelatin (Cs/Gel) matrix. HA, as a bridge, not only was used as a dopant, but also combined PEDOT into the Cs/Gel via chemical crosslinking. The PEDOT-HA/Cs/Gel scaffold was used as a conductive substrate for neural stem cell (NSC) culture in vitro. The results demonstrated that the PEDOT-HA/Cs/Gel scaffold had excellent biocompatibility for NSC proliferation and differentiation. 3D confocal fluorescence images showed cells attached on the channel surface of Cs/Gel and PEDOT-HA/Cs/Gel scaffolds with a normal neuronal morphology. Compared to the Cs/Gel scaffold, the PEDOT-HA/Cs/Gel scaffold not only promoted NSC proliferation with up-regulated expression of Ki67, but also enhanced NSC differentiation into neurons and astrocytes with up-regulated expression of ß tubulin-III and GFAP, respectively. It is expected that this electro-active and bio-active PEDOT-HA/Cs/Gel scaffold will be used as a conductive platform to regulate NSC behavior for neural tissue engineering.


Assuntos
Materiais Biocompatíveis/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/química , Diferenciação Celular/efeitos dos fármacos , Quitosana/química , Células-Tronco Neurais/citologia , Polímeros/química , Engenharia Tecidual , Tecidos Suporte/química , Animais , Materiais Biocompatíveis/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Géis , Células-Tronco Neurais/efeitos dos fármacos , Células PC12 , Gravidez , Ratos
9.
Langmuir ; 33(25): 6258-6268, 2017 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-28562053

RESUMO

The coalescence-induced droplet jumping on superhydrophobic surfaces (SHSs) has attracted considerable attention over the past several years. Most of the studies on droplet jumping mainly focus on two-droplet coalescence events whereas the coalescence of three or more droplets is actually more frequent and still remains poorly understood. In this work, a 3D lattice Boltzmann simulation is carried out to investigate the effect of initial droplet arrangements on the coalescence-induced jumping of three equally sized droplets. Depending on the initial position of droplets on the surface, the droplet coalescence behaviors can be generally classified into two types: one is that all droplets coalesce together instantaneously (concentrated configuration), and the other is that the initial coalesced droplet sweeps up the third droplet in its moving path (spaced configuration). The critical Ohnesorge number, Oh, for the transition of inertial-capillary-dominated coalescence to inertially limited-viscous coalescence is found to be 0.10 for droplet coalescence on SHSs with a contact angle of 160°. The jumping droplet velocity for concentrated multidroplet coalescence at Oh ⩽ 0.10 still follows the inertial-capillary scaling with an increased prefactor, which indicates a viable jumping droplet velocity enhancement scheme. However, the droplet jumping velocity is drastically reduced for the spaced configuration compared to that for the aforementioned concentrated configuration. Because Oh exceeds 0.10, the effects of initial droplet arrangements on multidroplet jumping become weaker as viscosity plays a key role in the merging process. This work will provide effective guidelines for the design of functional SHSs with enhanced droplet jumping for a wide range of industrial applications.

10.
Sci Rep ; 7(1): 987, 2017 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-28428638

RESUMO

Condensation is a common physical process which widely exists in natural phenomena and thermal energy systems. In a condensation process, cluster is considered as the important bridge between vapor body and condensates. However, limited by the minimum imaging dimension of traditional measurements, early experimental studies about initial stages of condensation process are not sufficient. This paper provides a powerful optical platform for the study of dynamic clusters process. Based on the Rayleigh law, optical experiments were firstly introduced to investigate the clusters spatial distribution close to and far from condensation surface. The results show that clusters are mainly generated in the vicinity of the condensation surface within the thickness of 200 µm. When they move away from the condensation surface, clusters progressively vanish and they have a life cycle of a fraction of a millisecond. Though scattering intensity is proportional to the 6th power of cluster radius r and cluster number density N c theoretically, the scattering intensity does not increase sharply with the increase of subcooling degree from the experimental results, so we can infer that the cluster number density plays a dominate role in this process and the effect of cluster radius almost can be ignored.Zhong Lan and Di Wang contributed equally to this work.

11.
ACS Appl Mater Interfaces ; 9(15): 13770-13777, 2017 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-28362085

RESUMO

Nanostructured superhydrophobic surfaces have been actively explored to promote favorable droplet dynamics for a wide range of technological applications. However, the tendency of condensed droplets to form as pinned states greatly limits their applicability in enhancing condensation heat transfer efficiency. Despite recent progresses, the understanding of physical mechanisms governing the wetting transition of condensed droplets is still lacking. In this work, a nanostructured superhydrophobic surface with tapered nanogaps is fabricated to demonstrate the coordination of surface wetting property, topography, and the condensing condition on the wetting state and dynamic behavior of condensed droplets. Combining the environmental scanning electron microscopy and optical visualization methods, we systematically show the morphology of nucleated droplets in nanostructures and the droplet dynamic evolution throughout the growth stages, which provides the direct evidence of condensing condition-induced droplet wetting transition. When the surface subcooling is smaller than 0.3 K, the droplets formed as the Cassie-Baxter state, followed by coalescence-induced droplet jumping. With the increase of surface subcooling up to 0.6 K, however, droplet formation occurs randomly inside nanogaps, resulting in the loss of superhydrophobicity. These new observations along with the new insights about the coordination of surface properties and condensing conditions on droplet wetting transition are useful for guiding the development of novel surfaces for improving droplet removal and phase-change heat transfer.

12.
J Biosci Bioeng ; 123(1): 116-125, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27498308

RESUMO

Poly 3,4-ethylenedioxythiophene (PEDOT), a polythiophene derivative, has been proved to be modified by chemical process as biocompatible conductive polymer for biomedical applications. In this study, novel hyaluronic acid (HA)-doped PEDOT nanoparticles were synthesized by the method of chemical oxidative polymerization, then conductive PEDOT-HA/poly(l-lactic acid) (PLLA) composite films were prepared. The physicochemical characteristics and biocompatibility of films were further investigated. FTIR, Raman and EDX analysis demonstrated that HA was successfully doped into PEDOT particles. Cyclic voltammograms indicated PEDOT-HA particles had favorable electrochemical stability. PEDOT-HA/PLLA films showed lower surface contact angle and faster degradation degree compared with PLLA films. Moreover, the cytotoxicity test of PEDOT-HA/PLLA films showed that neuron-like pheochromocytoma (PC12) cells adhered and spread well on the surface of PEDOT-HA/PLLA films and cell viability denoted by MTT assay had a significant increase. PEDOT-HA/PLLA films modified with laminin (LN) also exhibited an efficiently elongated cell morphology observed by fluorescent microscope and metallographic microscope. Furthermore, PEDOT-HA/PLLA films were subjected to different current intensity to elucidate the effect of electrical stimulation (ES) on neurite outgrowth of PC12 cells. ES (0.5 mA, 2 h) significantly promoted neurite outgrowth with an average value length of 122 ± 5 µm and enhanced the mRNA expression of growth-associated protein (GAP43) and synaptophysin (SYP) in PC12 cells when compared with other ES groups. These results suggest that PEDOT-HA/PLLA film combined with ES are conducive to cell growth and neurite outgrowth, indicating the conductive PEDOT-HA/PLLA film may be an attractive candidate with ES for enhancing nerve regeneration in nerve tissue engineering.


Assuntos
Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/química , Condutividade Elétrica , Ácido Hialurônico/química , Poliésteres/química , Polímeros/química , Animais , Regeneração Nervosa/efeitos dos fármacos , Células PC12 , Ratos , Engenharia Tecidual
13.
Mater Sci Eng C Mater Biol Appl ; 71: 308-316, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27987712

RESUMO

Conducting polymer, as a "smart" biomaterial, has been increasingly used to construct tissue engineered scaffold for nerve tissue regeneration. In this study, a novel porous conductive scaffold was prepared by incorporating conductive hyaluronic acid (HA) doped-poly(3,4-ethylenedioxythiophene) (PEDOT-HA) nanoparticles into a chitosan/gelatin (Cs/Gel) matrix. The physicochemical characteristics of Cs/Gel scaffold with 0-10wt% PEDOT-HA were analyzed and the results indicated that the incorporation of PEDOT-HA into scaffold increased the electrical and mechanical properties while decreasing the porosity and water absorption. Moreover, in vitro biodegradation of scaffold displayed a declining trend with the PEDOT-HA content increased. About the biocompatibility of conductive scaffold, neuron-like rat phaeochromocytoma (PC12) cells were cultured in scaffold to evaluate cell adhesion and growth. 8% PEDOT-HA/Cs/Gel scaffold had a higher cell adhesive efficiency and cell viability than the other conductive scaffolds. Furthermore, cells in the scaffold with 8wt% PEDOT-HA expressed higher synapse growth gene of GAP43 and SYP compared with Cs/Gel control group. These results suggest that 8%PEDOT-HA/Cs/Gel scaffold is an attractive cell culture conductive substrate which could support cell adhesion, survival, proliferation, and synapse growth for the application in nerve tissue regeneration.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Diferenciação Celular/efeitos dos fármacos , Ácido Hialurônico , Regeneração Nervosa/efeitos dos fármacos , Polímeros , Tecidos Suporte/química , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Adesão Celular/efeitos dos fármacos , Géis , Ácido Hialurônico/química , Ácido Hialurônico/farmacocinética , Ácido Hialurônico/farmacologia , Células PC12 , Polímeros/química , Polímeros/farmacocinética , Polímeros/farmacologia , Ratos
14.
Sci Rep ; 6: 18836, 2016 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-26743167

RESUMO

The behavior of droplets trapped in geometric structures is essential to droplet manipulation applications such as for droplet transport. Here we show that directional droplet movement can be realized by a V-shaped groove with the movement direction controlled by adjusting the surface wettability of the groove inner wall and the cross sectional angle of the groove. Experiments and analyses show that a droplet in a superhydrophobic groove translates from the immersed state to the suspended state as the cross sectional angle of the groove decreases and the suspended droplet departs from the groove bottom as the droplet volume increases. We also demonstrate that this simple grooved structure can be used to separate a water-oil mixture and generate droplets with the desired sizes. The structural effect actuated droplet movements provide a controllable droplet transport method which can be used in a wide range of droplet manipulation applications.

15.
Int J Dev Neurosci ; 42: 37-45, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25702528

RESUMO

Pyrroloquinoline quinone (PQQ), as a well-known redox enzyme cofactor, has been proven to play important roles in the regulation of cellular growth and development in mammals. Numerous physiological and medicinal functions of PQQ have so far been reported although its effect on neural stem and progenitor cells (NS/PCs) and the potential mechanism were even rarely investigated. In this study, the neuroprotective effects of PQQ were observed by pretreatment of NS/PCs with PQQ before glutamate injury, and the possible mechanisms were examined. PQQ stimulated cell proliferation and markedly attenuated glutamate-induced cell damage in a dose-dependent manner. By observing the nuclear morphological changes and flow cytometric analysis, PQQ pretreatment showed its significant effect on protecting NS/PCs against glutamate-induced apoptosis/necrosis. PQQ neuroprotection was associated with the decrease of intracellular reactive oxygen species (ROS) production, the increase of glutathione (GSH) levels, and the decrease of caspase-3 activity. In addition, pretreatment with PQQ also significantly enhanced the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in the NS/PCs exposed to glutamate. These results suggest that PQQ can protect NS/PCs against glutamate toxicity associated with ROS-mediated mitochondrial pathway, indicating a useful chemical for the clinical application of NS/PCs.


Assuntos
Agonistas de Aminoácidos Excitatórios/toxicidade , Ácido Glutâmico/toxicidade , Neurônios/efeitos dos fármacos , Cofator PQQ/farmacologia , Células-Tronco/efeitos dos fármacos , Animais , Anexina A5 , Antracenos , Apoptose/efeitos dos fármacos , Bromodesoxiuridina/metabolismo , Caspase 3/metabolismo , Tamanho do Núcleo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Embrião de Mamíferos , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Hipocampo/citologia , Necrose/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio , Sincalida/metabolismo
16.
Appl Biochem Biotechnol ; 174(6): 2114-30, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25163884

RESUMO

The aim of this study is to analyze the growth and substance metabolism of neural stem cells (NSCs) cultured in biological collagen-based scaffolds. Mass transfer and metabolism model of glucose, lactic acid, and dissolved oxygen (DO) were established and solved on MATLAB platform to obtain the concentration distributions of DO, glucose, and lactic acid in culture system, respectively. Calculation results showed that the DO influenced their normal growth and metabolism of NSCs mostly in the in vitro culture within collagen-based scaffolds. This study also confirmed that 2-mm thickness of collagen scaffold was capable of in vitro cultivation and growth of NSCs with an inoculating density of 1 × 10(6) cells/mL.


Assuntos
Técnicas de Cultura de Células/métodos , Colágeno/farmacologia , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Tecidos Suporte , Animais , Sobrevivência Celular/efeitos dos fármacos , Colágeno/química , Glucose/metabolismo , Cinética , Ácido Láctico/metabolismo , Camundongos , Células-Tronco Neurais/efeitos dos fármacos , Oxigênio/metabolismo , Ratos , Tecidos Suporte/química
17.
J Biomater Sci Polym Ed ; 24(8): 999-1014, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23647254

RESUMO

The novel chitosan (Cs)/gelatin (Gel) porous scaffolds containing hyaluronic acid (HA) and heparan sulfate (HS) were fabricated via freeze-drying technique, and their physicochemical characteristics including pore size, porosity, water absorption, and in vitro degradation and biocompatibility were investigated. It was demonstrated that the Cs/Gel/HA/HS composite scaffolds had highly homogeneous and interconnected pores with porosity above 96% and average pore size ranging from 90 to 140 µm and a controllable degradation rate. The scanning electron microscopic images, cell viability assay, and fluorescence microscopy observation revealed that the presence of HA and HS in the scaffolds significantly promoted initial neural stem and progenitor cells (NS/PCs) adhesion and supported long-time growth in three-dimensional environment. Moreover, NS/PCs also maintained mutilineage differentiation potentials with enhanced neuronal differentiation upon induction in the Cs/Gel/HA/HS composite scaffolds in relation to Cs/Gel scaffolds. These results indicated that the Cs/Gel/HA/HS composite scaffolds were suitable for neural cells' adhesion, survival, and growth and could offer new and important options for neural tissue engineering applications.


Assuntos
Quitosana/química , Gelatina/química , Heparitina Sulfato/química , Ácido Hialurônico/química , Células-Tronco Neurais/citologia , Tecidos Suporte , Animais , Adesão Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Teste de Materiais , Microscopia Eletrônica de Varredura , Células-Tronco Neurais/fisiologia , Porosidade , Ratos , Ratos Sprague-Dawley , Células-Tronco/citologia , Células-Tronco/fisiologia , Engenharia Tecidual
18.
Appl Biochem Biotechnol ; 170(2): 406-19, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23536252

RESUMO

A stable and fast method for constructing a neural-like tissue from rat neural stem/progenitor cells (rNS/PCs) based on three-dimensional (3D) collagen gel is described. First step, the collagen-embedded rNS/PCs expanded with the medium consisting of DMEM/F12/RPMI1640 (1:1:1) supplemented with EGF and bFGF was used to expand the cells in gel in 96-well plates until the average diameter of cell clusters was about 50-100 µm with the cell density higher than 10(7) cells/mL. In the second step, the initial medium was replaced with NB/B-27 supplemented with bFGF and BDNF. The results show that cells in collagen presented neural-like morphology and maintained live cell rate around 82 % in neural network pattern at least for 42 days under static conditions. The cell-collagen constructs were detected by immunofluorescence and immunohistochemistry test after 42 days of culture, part of cells still maintained the character of rNS/PCs, and others differentiated into neurons, astrocytes, and oligodendrocytes. Our 3D neural-like tissue construct was similar to the neural tissue in morphology and cell compositions. They thus have a potential to be used for drug screening, detection of environment toxins, and replacement therapy.


Assuntos
Diferenciação Celular , Forma Celular , Colágeno/metabolismo , Células-Tronco Neurais/citologia , Tecidos Suporte , Animais , Astrócitos/citologia , Astrócitos/metabolismo , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Contagem de Células , Técnicas de Cultura de Células , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Meios de Cultura/metabolismo , Fator 2 de Crescimento de Fibroblastos/farmacologia , Hipocampo/citologia , Hipocampo/metabolismo , Imageamento Tridimensional , Células-Tronco Neurais/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley
19.
Langmuir ; 29(4): 1129-38, 2013 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-23265312

RESUMO

Textured silicon surfaces decorated by square arrays of pillars with adjustable pitch were fabricated. The wetting behavior, especially for direction-dependent water contact angles on textured silicon surfaces after silanization, was investigated by incorporating the contact line fraction into a modified Wenzel model. Also, the effect of geometrical parameters on the anisotropic wetting behavior of water was examined with respect to water droplet impact on the textured surface. Moreover, the maximum spreading factor was studied theoretically in terms of energy conservation, allowing for surface topography and viscous friction of the liquid flowing among the arrays of the posts. Theoretical models were found to be in good agreement with experimental data.

20.
Eur J Pharmacol ; 670(2-3): 471-8, 2011 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-21946114

RESUMO

Protocatechuic acid (PCA), a phenolic compound isolated from the kernels of Alpinia (A.) oxyphylla, plays crucial roles in the proliferation and neuroprotection of cultured neural stem and progenitor cells (NS/PCs) in our previous study. However, whether PCA modulates the differentiation of NS/PCs has remained to be elucidated. In this study, we show that PCA can promote the neuronal differentiation combined with fetal bovine serum (FBS) in vitro, although it cannot initiate the differentiation of NS/PCs by itself. Moreover, PCA is able to induce neuronal maturation and efficiently promote neurite outgrowth. On the other hand, PCA facilitates survival of phenotypes differentiated from cultured NS/PCs, which was associated with an increased percentage of the cellular viability and a decreased percentage of cells undergoing apoptosis under differentiation conditions. In addition, PCA-induced survival is also mediated with the activating of endogenous antioxidant enzymes. These results suggest that PCA may serve as a useful reference for future studies in designing stem cell strategies to promote brain recovery and repair in neurodegenerative diseases.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Hidroxibenzoatos/farmacologia , Células-Tronco Neurais/citologia , Neurônios/citologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Alpinia/química , Animais , Apoptose/efeitos dos fármacos , Catalase/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Glutationa Peroxidase/metabolismo , Hidroxibenzoatos/isolamento & purificação , Neurônios/enzimologia , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
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