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1.
Environ Res ; 248: 118262, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38280523

RESUMO

The accelerated development of special-wetting polymeric materials with hierarchical pores for membrane applications is crucial to effectively separating water-soluble and insoluble pollutants, such as oily wastewater, emulsion, organic pollutants, and heavy metals. This pressing environmental and socioeconomic issue requires the implementation of effective remediation technologies. In this study, we successfully fabricated an environmentally friendly membrane with a flexible property by combining biopolymers and magnetic nanohybrids of iron oxide (Fe3O4)-doped tungsten oxide (WO3) through a thermal-induced phase separation process (TIPS). The resulting membrane exhibited a well-defined 3D-interconnected porous network structure when blending poly (ε-caprolactone)/poly (D,L-lactide) (PCL)/(PDLLA) in an 8:2 volume ratio. The Fe3O4@WO3 nanohybrids were synthesized using a hydrothermal process, resulting in a star-shaped morphology from the sea urchin-like WO3 clusters, which showed great potential to efficiently separate water/oil contamination and facilitate visible-light-driven photocatalytic degradation of organic dyes (MB, Rh B, BY, and CR) and photoreduction of hexavalent chromium (Cr (VI)). The obtained PCL/PDLLA/Fe3O4@WO3 nanocomposite membrane demonstrated hydrophobic properties, showing a water contact angle of 95 ± 2° and an excellent oil adsorption capacity of ∼4-4.5 g/g without fouling. The interconnected porous structure of the composite membrane enabled the efficient separation of emulsions (≥99.4 %) and achieved a high permeation flux of up to 1524 L m-2 h-1 under gravity separation. Overall, we obtained a novel high-performance composite material with specialized wetting properties, offering significant potential for effectively removing insoluble and soluble organic contaminants from wastewater.


Assuntos
Poluentes Ambientais , Recuperação e Remediação Ambiental , Águas Residuárias , Porosidade , Água , Polímeros
2.
Environ Res ; 221: 115285, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36640938

RESUMO

In recent years, the usage of nitroaniline has played a vital role in pharmaceutical formulations as it is a crucial ingredient in the synthesis of pesticides and dyes. However, the level of nitroaniline existing in industrial waste keeps rising the environmental contamination. Thus, monitoring of active nitro-residuals becomes more significant in reducing the toxicity of the ecosystem. Therefore, we have taken an attempt to evaluate the hazardous pollutant 2-nitroaniline (2-NA) using the electrocatalyst viz., tin-doped bismuth oxide inserted on a biopolymer silk fibroin composite modified glassy carbon electrode (Sn-Bi2O3/SF@GCE). The Sn-Bi2O3/SF nanocomposite was synthesized through hydrothermal and co-precipitation methods. The physicochemical properties of the prepared Sn-Bi2O3/SF hybrid composite were examined by conventional microscopy and spectroscopic techniques like FE-SEM, HR-TEM, XRD, FTIR, Raman, and XPS. Furthermore, the bio-mineralized Sn-Bi2O3/SF@GCE displayed a wide linear range (0.009 µM-785.7 µM) and a lower detection limit (3.5 nM) with good sensitivity for 2-NA detection under the optimum conditions. The result shows that the Sn-Bi2O3/SF-modified GCE has good reproducibility, repeatability, and excellent selectivity for 2-NA detection in the presence of other co-interfering compounds. Moreover, the practical applicability of Sn-Bi2O3/SF@GCE sensors was investigated for the effective detection of 2-NA in real river water samples, revealing good recovery results.


Assuntos
Fibroínas , Nanopartículas , Fibroínas/química , Estanho , Rios , Reprodutibilidade dos Testes , Ecossistema , Carbono/química , Água , Limite de Detecção
3.
Carbon N Y ; 1842021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37200678

RESUMO

Due to weak light-matter interaction, standard chemical vapor deposition (CVD)/exfoliated single-layer graphene-based photodetectors show low photoresponsivity (on the order of mA/W). However, epitaxial graphene (EG) offers a more viable approach for obtaining devices with good photoresponsivity. EG on 4H-SiC also hosts an interfacial buffer layer (IBL), which is the source of electron carriers applicable to quantum optoelectronic devices. We utilize these properties to demonstrate a gate-free, planar EG/4H-SiC-based device that enables us to observe the positive photoresponse for (405-532) nm and negative photoresponse for (632-980) nm laser excitation. The broadband binary photoresponse mainly originates from the energy band alignment of the IBL/EG interface and the highly sensitive work function of the EG. We find that the photoresponsivity of the device is > 10 A/W under 405 nm of power density 7.96 mW/cm2 at 1 V applied bias, which is three orders of magnitude greater than the obtained values of CVD/exfoliated graphene and higher than the required value for practical applications. These results path the way for selective light-triggered logic devices based on EG and can open a new window for broadband photodetection.

4.
Mikrochim Acta ; 188(3): 103, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33646401

RESUMO

Molybdenum disulfide (MoS2) surface functionalization was performed with a catechol-containing polymer sodium alginate (SA) and dopamine (DA) through simultaneous MoS2 exfoliation and self-polymerization of DA. The MoS2/SA-PDA nanocomposite was characterized using spectroscopic, microscopic, and electroanalytical techniques to evaluate its electrocatalytic performance. The electrocatalytic behavior of the MoS2/SA-PDA nanocomposite modified electrode for the detection of acebutolol (ACE), a cardio-selective ß-blocker drug was explored  through cyclic voltammetric and differential pulse voltammetric techniques. The influence of scan rate, concentration, and pH value on the oxidation peak current of ACE was investigated  to optimize the deducting condition. The electrochemical activity of the MoS2/SA-PDA nanocomposite electrode was attributed to the existence of reactive functional groups being contributed from SA, PDA, and MoS2 exhibiting a synergic effect. The MoS2/SA-PDA nanocomposite modified electrode exhibits admirable electrocatalytic activity with a wide linear response range (0.009 to 520 µM), low detection limit (5 nM), and high sensitivity (0.354 µA µM-1 cm-2) also in the presence of similar (potentially interfering) compounds. The fabricated MoS2/SA-PDA nanocomposite modified electrode can be useful for the detection of ACE in pharmaceutical analysis.


Assuntos
Acebutolol/análise , Antagonistas de Receptores Adrenérgicos beta 1/análise , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Nanocompostos/química , Acebutolol/sangue , Acebutolol/química , Acebutolol/urina , Antagonistas de Receptores Adrenérgicos beta 1/sangue , Antagonistas de Receptores Adrenérgicos beta 1/química , Antagonistas de Receptores Adrenérgicos beta 1/urina , Alginatos/química , Técnicas Biossensoriais/métodos , Dissulfetos/química , Técnicas Eletroquímicas/métodos , Eletrodos , Humanos , Indóis/química , Limite de Detecção , Molibdênio/química , Oxirredução , Polímeros/química , Reprodutibilidade dos Testes
5.
Int J Mol Sci ; 21(22)2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33207764

RESUMO

Studies using polymeric scaffolds for various biomedical applications, such as tissue engineering, implants and medical substitutes, and drug delivery systems, have attempted to identify suitable material for tissue regeneration. This study aimed to investigate the biocompatibility and effectiveness of a gelatin scaffold seeded with human adipose stem cells (hASCs), including physical characteristics, multilineage differentiation in vitro, and osteogenic potential, in a rat model of a calvarial bone defect and to optimize its design. This functionalized scaffold comprised gelatin-hASCs layers to improve their efficacy in various biomedical applications. The gelatin scaffold exhibited excellent biocompatibility in vitro after two weeks of implantation. Furthermore, the gelatin scaffold supported and specifically regulated the proliferation and osteogenic and chondrogenic differentiation of hASCs, respectively. After 12 weeks of implantation, upon treatment with the gelatin-hASCs scaffold, the calvarial bone harboring the critical defect regenerated better and displayed greater osteogenic potential without any damage to the surrounding tissues compared to the untreated bone defect. These findings suggest that the present gelatin scaffold is a good potential carrier for stem cells in various tissue engineering applications.


Assuntos
Diferenciação Celular , Células Imobilizadas , Gelatina/química , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Crânio , Engenharia Tecidual , Alicerces Teciduais/química , Animais , Células Imobilizadas/metabolismo , Células Imobilizadas/transplante , Xenoenxertos , Humanos , Masculino , Ratos , Ratos Sprague-Dawley , Crânio/lesões , Crânio/metabolismo , Crânio/patologia
6.
J Mater Sci Mater Med ; 29(7): 100, 2018 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-29946882

RESUMO

The original version of this article unfortunately contained a mistake. The country was incorrect in the authors affiliations. It should read as "ROC". The corrected affiliations are given below.

7.
J Mater Sci Mater Med ; 28(12): 192, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29143185

RESUMO

Stem cells derived from oral tissue represent a highly attractive alternative source for clinical bone regeneration because they can be collected by non-invasive or minimally invasive procedures. Herein, we describe the human dental stem cells (DSCs) deriving from buccal fat pads (BFP), dental pulp (DP) of impacted teeth, and periodontal ligaments (PDL) to obtain BFPSCs, DPSCs, and PDLSCs, respectively. Cells were purified with selected medium and expanded through passages in stem cell culture medium. Purified cells were characterized for stemness by their growth rate, immunostaining, and multilineage differentiation ability. They showed plastic adherence, expression of stemness-specific markers, and multilineage differentiation potential. Immunocytochemistry analysis confirmed that DPSCs had more osteogenic potential than BFSCs and PDLSCs. Calcium-rich deposits, evaluated by von Kossa and Alizarin red staining, showed greater mineralization when DPSCs were cultured on collagen type I matrix than without collagen. Furthermore, DPSC-seeded collagen type I matrix maintained consistent osteogenesis and boosted mineral formation by 1-2 weeks over that in DPSCs cultured without collagen. Radiographic analysis of DPSC-seeded collagen type I matrix transplanted into rat cranial defects showed significant bone regeneration after 8 weeks. These results suggested that the redundant oral tissue can be used as a source of adult multipotent stem cells for clinical bone regeneration. Triple overlay images with biomarkers (red), nuclei (blue) and bright field morphology of DPSCs. The specifically osteo-differentiation shown by osteocalcin (left) expression and lack of sox9 (right) expressed in the images below which were cultured with collagen matrix, contrast with no collagen matrix group above.


Assuntos
Tecido Adiposo/citologia , Colágeno Tipo I , Polpa Dentária/citologia , Osteogênese/fisiologia , Ligamento Periodontal/citologia , Células-Tronco/fisiologia , Animais , Transplante Ósseo , Técnicas de Cultura de Células , Humanos , Ratos
8.
Acta Cardiol Sin ; 32(4): 485-90, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27471362

RESUMO

BACKGROUND: It has been observed that acetaminophen shows cardioprotective efficacy in mammals. In this study, we investigated the electromechanical effects of acetaminophen on the left atrium (LA). METHODS: Conventional microelectrodes were used to record the action potentials (AP) in rabbit LA preparations. The action potential duration (APD) at repolarization levels of 90%, 50% and 20% of the AP amplitude (APD90, APD50, and APD20, respectively), resting membrane potential, and contractile force were measured during 2 Hz electrical stimulation before and after sequential acetaminophen administration to the LA. RESULTS: Acetaminophen (0.1, 0.3, 1, and 3 mM) reduced APD20 from 9.4 ± 1.2 to 8.0 ± 1.1 (p < 0.05), 7.1 ± 0.8 (p < 0.05), 7.8 ± 1.1, and 6.8 ± 1.2 ms (p < 0.05), respectively, and APD50 from 20.2 ± 1.9 to 17.4 ± 2.0, 15.6 ± 1.8 (p < 0.05), 15.8 ± 2.2 (p < 0.05), and 14.1 ± 2.4 ms (p < 0.05), respectively, in a concentration-dependent manner. APD90 was reduced from 72.0 ± 3.6 to 64.7 ± 4.2, 61.9 ± 4.3, 60.5 ± 3.7, and 53.4 ± 4.4 ms (p < 0.05), respectively. Acetaminophen increased LA contractility from 45 ± 9 to 52 ± 10 (p < 0.05), 55 ± 9 (p < 0.01), 58 ± 9 (p < 0.01), and 60 ± 9 mg (p < 0.01), respectively, in a concentration-dependent manner. In the presence of the NOS inhibitor L-NAME or PKG-I inhibitor DT-2, additional acetaminophen treatment did not significantly increase LA contractility. CONCLUSIONS: Acetaminophen modulated the electromechanical characteristics of LA by inhibiting the NOS and PKG I pathway, and then contributed to the positive inotropic effect.

9.
Ann Plast Surg ; 71 Suppl 1: S67-74, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24284744

RESUMO

Embryonic stem cells (ESCs) are pluripotent cells that can differentiate into various cell types, including keratinocyte-like cells, within suitable microniches. In this study, we aimed to investigate the effects of culture media, cell coculture, and a tissue-engineering biocomposite on the differentiation of mouse ESCs (MESCs) into keratinocyte-like cells and applied these cells to a surgical skin wound model. MESCs from BALB/c mice (ESC26GJ), which were transfected using pCX-EGFP expressing green fluorescence, were used to track MESC-derived keratinocytes. Weak expression of the keratinocyte early marker Cytokeratin 14 (CK-14) was observed up to 12 days when MESCs were cultured in a keratinocyte culture medium on tissue culture plastic and on a gelatin/collagen/polycaprolactone (GCP) biocomposite. MESCs cocultured with human keratinocyte cells (HKCs) also expressed CK-14, but did not express CK-14 when cocultured with human fibroblast cells (HFCs). Furthermore, CK-14 expression was observed when MESCs were cocultured by seeding HKCs or HFCs on the same or opposite side of the GCP biocomposite. The highest CK-14 expression was observed by seeding MESCs and HKCs on the same side of the GCP composite and with HFCs on the opposite side. To verify the effectiveness of wound healing in vivo, adipose-derived stem cells were applied to treat surgical wounds in nude mice. An obvious epidermis multilayer and better collagen deposition during wound healing were observed, as assessed by Masson staining. This study demonstrated the potential of keratinocyte-like differentiation from mesenchymal stem cells for use in promoting wound closure and skin regeneration.


Assuntos
Técnicas de Cocultura , Meios de Cultura , Queratinócitos/citologia , Engenharia Tecidual/métodos , Cicatrização/fisiologia , Animais , Diferenciação Celular , Fibroblastos/citologia , Humanos , Queratinócitos/metabolismo , Células-Tronco Mesenquimais/fisiologia , Camundongos , Camundongos Nus
10.
Materials (Basel) ; 16(12)2023 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-37374498

RESUMO

Reduced graphene oxide (rGO) has been used in copper (II) oxide (CuO)-based photocatalysts as an additive material. An application of this CuO-based photocatalyst is in the CO2 reduction process. The preparation of rGO by a Zn-modified Hummers' method has resulted in a high quality of rGO in terms of excellent crystallinity and morphology. However, implementing Zn-modified rGO in CuO-based photocatalysts for the CO2 reduction process has yet to be studied. Therefore, this study explores the potential of combining Zn-modified rGO with CuO photocatalysts and performing these rGO/CuO composite photocatalysts to convert CO2 into valuable chemical products. The rGO was synthesized by using a Zn-modified Hummers' method and covalently grafted with CuO by amine functionalization with three different compositions (1:10, 1:20, and 1:30) of rGO/CuO photocatalyst. XRD, FTIR, and SEM were used to investigate the crystallinity, chemical bonds, and morphology of the prepared rGO and rGO/CuO composites. The performance of rGO/CuO photocatalysts for the CO2 reduction process was quantitively measured by GC-MS. We found that the rGO showed successful reduction using a Zn reducing agent. The rGO sheet could be grafted with CuO particles and resulted in a good morphology of rGO/CuO, as shown from the XRD, FTIR, and SEM results. The rGO/CuO material showed photocatalytic performance due to the advantages of synergistic components and resulted in methanol, ethanolamine, and aldehyde as fuel with amounts of 37.12, 8730, and 17.1 mmol/g catalyst, respectively. Meanwhile, adding CO2 flow time increases the resulting quantity of the product. In conclusion, the rGO/CuO composite could have potential for large-scale CO2 conversion and storage applications.

11.
J Agric Food Chem ; 71(51): 20563-20574, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38109259

RESUMO

The phenolic compound trichlorophenol (TCP) is an ingredient in fungicides and herbicides. This compound's high stability, bioaccumulation, toxicity, and poor biodegradability result in severe environmental and biological health issues. Consequently, it is crucial to have an affordable and sensitive method for detecting TCP in environmental samples. In this study, α-phase bismuth oxide microplates and polydopamine-functionalized reduced graphene oxide (α-Bi2O3 MPs/PDA-RGO) were synthesized using a simple ultrasonic method and characterized with various analytical and physical characterizations. The conversion of the catechol moieties present in the resulting PDA-RGO material into quinones facilitates productive interactions with diverse functional groups, such as hydroxyl, amine, and imine. Consequently, the compounds 2,4,6-trichlorophenol (TCP) engages in electrochemical interactions with the aforementioned functional groups. As a result, TCP shows more excellent selectivity on the designed α-Bi2O3 MPs/PDA-RGO/SPCE sensor. Under the optimized conditions, the sensor demonstrated a lower detection limit (0.0042 µM), a limit of quantification (0.0078 µM), good sensitivity (2.24 µA µM-1 cm2), a wide linear range (0.019-190.7 and 212.7-1649 µM), and pinpoint specificity. The efficacy of the sensor is additionally validated through the accurate identification of TCP residues in water, soil, and food samples.


Assuntos
Grafite , Grafite/química , Fenóis , Água , Técnicas Eletroquímicas/métodos
12.
Ann Plast Surg ; 69(6): 650-5, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23154337

RESUMO

There is an urgent need to develop tissue-engineered cartilage for patients experiencing joint malfunction due to insufficient self-repairing capacity of articular cartilage. The aim of this research was to explore the effect of hyperbaric oxygen and air on tissue-engineered cartilage formation from human adipose-derived stem cells seeding on the gelatin/polycaprolactone biocomposites. The results of histological analyses indicate that under hyperbaric oxygen and air stimulation, the cell number of chondrocytes in cartilage matrix was not significantly increased, but the 1,9-dimethylmethylene blue assay showed that the glycosaminoglycans syntheses markedly increased compared to the control group. In quantification real-time polymerase chain reaction results, the chondrogenic-specific gene expression of SOX9, aggrecan, and COL2A1 were compared respectively. Within the limitation of this study, it was concluded that 2.5 atmosphere absolute oxygen and air may provide a stress environment to help cartilage tissue engineering development.


Assuntos
Ar , Cartilagem/citologia , Condrogênese , Oxigenoterapia Hiperbárica , Engenharia Tecidual/métodos , Adipócitos/citologia , Análise de Variância , Diferenciação Celular , Sobrevivência Celular , Condrogênese/genética , Matriz Extracelular , Humanos , Células-Tronco/citologia
13.
Langmuir ; 27(18): 11690-6, 2011 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-21842869

RESUMO

Nanohybrids of silver nanoparticles (AgNPs) supported on mica clay were synthesized by in situ reduction of silver nitrate in an aqueous solution. The required mica platelets of high aspect ratio were previously prepared by the exfoliation of mica clay stacks in a multilayered structure through an ionic exchange reaction with poly(oxypropylene)-amine-salt. The exfoliated nanoscale mica platelets (Mica) are polydispersed such that each platelet is 300-1000 nm in width and 1 nm in thickness. These platelets possess ionic charges in the form of ≡SiO(-)Na(+) at 120 mequiv/100 g and are suitable for supporting AgNPs in the process of in situ reduction of silver nitrate. Transmission electronic microscopy revealed the formation of AgNPs with a narrow size distribution of ca. 8 nm in diameter on the rim of individual Mica platelets. However, the pristine layered Mica structure without exfoliation failed to produce a fine AgNP distribution but instead generated particles larger than 30 nm and some precipitates. Characterization by differential scanning calorimetry and field emission scanning electron microscopy revealed that the fine AgNPs on Mica platelets exhibited a low melting temperature of 110 °C. The AgNP/Mica nanohybrid not containing an organic dispersant is considered to be a "naked" silver particle.

14.
Langmuir ; 27(2): 766-73, 2011 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-21155549

RESUMO

A novel synthesis of "hairy urchin"-shaped polyaniline (PAni) and its surface coverage with nanospikes was achieved from a simple microemulsion polymerization technique in the presence of ß-cyclodextrin (ß-CD). The rodlike micelle phase was characterized, and the key factors affecting the formation of PAni nanostructures were systematically examined. Ferric chloride (FeCl(3)) has played a role as a structural directing agent to fabricate the polymer as hairy urchin-like structure/nanorods via a cooperative interaction between FeCl(3) and DoTAC in an aqueous medium. Host-guest inclusion complex of ß-cyclodextrin with aniline was used as a monomer. It has been revealed that the formation of the supramolecular complexes of polyaniline with ß-CD due to host-guest interaction is indispensable for the fabrication of these unique PAni nanostructures, and a suitable ß-CD to aniline molar ratio is essential to their exclusive formation. Different varieties of PAni nanostructures such as hairy urchin, branched particles consisting of rodlike branches, and regular rodlike particles were obtained in the presence of FeCl(3). Also, in the absence of FeCl(3), a predominant product of regular spherical particles and wirelike aggregation exhibiting faceted surfaces were obtained. The structures of polyaniline hairy urchin-like nanorods were analyzed using transmission electron microscopy (TEM). The synthesized polymer was characterized by Fourier-transform infrared spectroscopy and X-ray diffraction technique. Additionally, the relationship between the morphology and the conductivity of the PAni nanostructures was investigated as well.


Assuntos
Compostos de Anilina/química , Compostos de Anilina/síntese química , beta-Ciclodextrinas/química , Cloretos/química , Compostos Férricos/química , Micelas , Nanoestruturas/química , Tamanho da Partícula , Compostos de Amônio Quaternário/química , Propriedades de Superfície , Tensoativos/química
15.
Phys Chem Chem Phys ; 13(25): 11892-904, 2011 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-21617802

RESUMO

Solvent mixtures often alter the solubility of polymeric substances. Statistical copolymers made from 2-methyl-2-oxazoline (MeOx) and 2-phenyl-2-oxazoline (PhOx) are known for their varying solubilities in pure ethanol, pure water and in binary mixtures of ethanol-water. Constrained Molecular Dynamics (MD) simulations have been carried out with an aim to explain the varying solubilities of the statistical MeOx-PhOx copolymers. The solute-solvent dynamic friction kernels calculated through constrained MD simulations corroborate the solubility pattern in these copolymers. The solvation characteristics have been analyzed in terms of the solute-solvent radial distribution functions (RDFs). The ethanol-soluble MeOx-PhOx copolymers exhibit characteristic solute-composition dependence in the dynamic solute-solvent friction kernels, indicating the strength of the solute-solvent correlations. The aggressive solvation by the ethanol molecules in the binary solvent mixtures has been brought out by the O(solute)-H(ethanol) RDFs which exhibit a characteristic dependence on the ethanol content in the solvent composition. The corresponding O(solute)-H(water) RDFs are devoid of any such composition dependence. For all the MeOx-PhOx copolymers, the O-site solvation is strongly dominated by the water molecules and the N-sites are solvated equally by both ethanol and water molecules.


Assuntos
Etanol/química , Oxazóis/química , Polímeros/química , Água/química , Simulação de Dinâmica Molecular , Soluções/química , Solventes/química
16.
J Nanosci Nanotechnol ; 11(2): 1004-12, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21456130

RESUMO

Carbon micro coils (CMCs) were hybridized with poly(vinyl alcohol) (PVA) through esterification reaction. The mixing of as-prepared CMC hybrid with polymer (PVA) matrix was effective to prepare PVA film where the functionalized CMC was homogeneously dispersed and embedded. The presence of CMCs in PVA film heightened the glass transition temperature of PVA. Results of tensile stress and electrical conductivity indicated that overall mechanical and electrical properties of PVA film were enforced by embedding CMC, depending on increase of the CMC concentration. These properties were further reinforced by prefunctionalization of CMC by PVA, because CMC can have an affinity to PVA in matrix through PVA immobilized on CMCs. However, mechanical and electrical properties for both nonfunctionalized and functionalized composites were depressed above a certain CMC concentration, indicating the self-orientation of CMC in the matrix, different from the behavior of carbon black.

18.
Polymers (Basel) ; 12(4)2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32272682

RESUMO

Recently, stem cell-based bone tissue engineering (BTE) has been recognized as a preferable and clinically significant strategy for bone repair. In this study, a pure 3D silk fibroin (SF) scaffold was fabricated as a BTE material using a lyophilization method. We aimed to investigate the efficacy of the SF scaffold with and without seeded human adipose-derived mesenchymal stem cells (hASCs) in facilitating bone regeneration. The effectiveness of the SF-hASCs scaffold was evaluated based on physical characterization, biocompatibility, osteogenic differentiation in vitro, and bone regeneration in critical rat calvarial defects in vivo. The SF scaffold demonstrated superior biocompatibility and significantly promoted osteogenic differentiation of hASCs in vitro. At six and twelve weeks postimplantation, micro-CT showed no statistical difference in new bone formation amongst all groups. However, histological staining results revealed that the SF-hASCs scaffold exhibited a better bone extracellular matrix deposition in the defect regions compared to other groups. Immunohistochemical staining confirmed this result; expression of osteoblast-related genes (BMP-2, COL1a1, and OCN) with the SF-hASCs scaffold treatment was remarkably positive, indicating their ability to achieve effective bone remodeling. Thus, these findings demonstrate that SF can serve as a potential carrier for stem cells, to be used as an osteoconductive bioscaffold for BTE applications.

19.
Diagnostics (Basel) ; 10(6)2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-32545649

RESUMO

The BK virus (BKV) is an emerging pathogen in immunocompromised individuals and widespread in the human population. Polymerase chain reaction is a simple and highly sensitive method for detecting BKV, but it is time consuming and requires expensive instruments and expert judgment. The lateral flow assay, a rapid, low-cost, minimal-labor, and easy-to-use diagnostic method, was successfully applied for pathogen detection. In this study, we used oligonucleotide probes to develop a simple and rapid sandwich-type lateral flow immunoassay for detecting BKV DNA within 45 minutes. The detection limit for the synthetic single-stranded DNA was 5 nM. The specificity study showed no cross-reactivity with other polyomaviruses, such as JC virus and simian virus 40. For the Escherichia coli containing BKV plasmid cultured samples, the sensitivity was determined to be 107 copies/mL. The approach offers great potential for BKV detection of various target analytes in point-of-care settings.

20.
J Vis Exp ; (145)2019 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-30907875

RESUMO

This article presents an inexpensive method to fabricate gelatin, as a natural polymer, into monofilament fibers or other appropriate forms. Through the wet spinning method, gelatin fibers are produced by smooth extrusion in a suitable coagulation medium. To increase the functional surface of these gelatin fibers and their ability to mimic the features of tissues, gelatin can be molded into a tube form by referring to this concept. Examined by in vitro and in vivo tests, the gelatin tubes demonstrate a great potential for application in tissue engineering. Acting as a suitable filling gap material, gelatin tubes can be used to substitute the tissue in the damaged area (e.g., in the nervous or cardiovascular system), as well as to promote regeneration by providing a direct replacement of stem cells and neural circuitry. This protocol provides a detailed procedure for creating a biomaterial based on a natural polymer, and its implementation is expected to greatly benefit the development of correlative natural polymers, which help to realize tissue regeneration strategies.


Assuntos
Gelatina/farmacologia , Engenharia Tecidual/métodos , Animais , Proliferação de Células/efeitos dos fármacos , Humanos , Ratos , Regeneração/efeitos dos fármacos , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Alicerces Teciduais/química
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