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61.
Influence of mechanical characteristics and matrix architecture of substrates used in cell culture is an important issue to tissue engineering. Chitosan‐based materials have been processed into porous structures, injectable gels and membranes, and are investigated to regenerate various tissues. However, the effect of these structures on cell growth and matrix production in accordance with each of the differing scaffolds has not been examined. We investigated the influence of porous structures, hydrogels, and membranes on the growth of normal human fibroblasts and their matrix production in a serum‐free system. We used chitosan alone and in combination with gelatin. Injectable hydrogels were prepared using 2‐glycerol phosphate. From the same solution, porous scaffolds and membranes were formed using controlled rate freezing and lyophilization, and air‐drying, respectively. Fibroblast growth was evaluated on the 4th and 10th days using flow cytometry and CFDA‐SE pre‐staining. Cell morphology was assessed using actin and nucleus staining. Total protein content, collagen, tropoelastin, and MMP2/MMP‐9 activity in the media supernatant were assessed by BCA, Sircol?, Fastin Elastin, and fluorogeneic peptide assays. Collagen accumulated in the matrix was assessed by Sircol? assay after pepsin/acetic acid digestion and by Masson's Trichrome staining. These results showed increased viability of fibroblasts on chitosan–gelatin porous scaffold with decreased proliferation relative to tissue culture plastic (TCP) surface despite the cells showing spindle shape. The total protein, collagen, and tropoelastin contents were higher in the spent media from chitosan–gelatin porous scaffolds compared to other conditions. MMP2/MMP9 activity was comparable to TCP. An increase in collagen content was also observed in the matrix, suggesting increased matrix deposition. In summary, matrix production is influenced by the form of chitosan structures, which significantly affects the regenerative process. Biotechnol. Bioeng. 2012; 109:1314–1325. © 2011 Wiley Periodicals, Inc. 相似文献
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Homayoon Soleimani Dinani Mehrab Pourmadadi Fatemeh Yazdian Hamid Rashedi Seyed Ali Seyed Ebrahimi Javad Shabani Shayeh Mehdi Ghorbani 《Engineering in Life Science》2022,22(8):519
Due to their high sensitivity, simplicity, portability, self‐contained, and low cost, the development of electrochemical biosensors is a beneficial way to diagnose and anticipate many types of cancers. An electrochemical nanocomposite‐based aptasensor is fabricated for the determination of miRNA‐128 concentration as the acute lymphoblastic leukemia (ALL) biomarker for the first time. The aptamer chains were immobilized on the surface of the glassy carbon electrode (GCE) through gold nanoparticles/magnetite/reduced graphene oxide (AuNPs/Fe3O4/RGO). Fast Fourier transform infrared (FTIR), X‐ray diffraction (XRD), vibrating sample magnetometer (VSM), and transmission electron microscopy (TEM) were used to characterize synthesized nanomaterials. Cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS) were used to characterize the modified GCE in both label‐free and labeled methods. The results indicate that the modified working electrode has high selectivity and for miRNA‐128 over other biomolecules. The hexacyanoferrate redox system typically operated at around 0.3 V (vs. Ag/AgCl), and the methylene blue redox system ran at about 0 V, were used as an electrochemical probe. The detection limit and linear detection range for hexacyanoferrate and methylene blue are 0.05346 fM, 0.1–0.9 fM, and 0.005483 fM, 0.01–0.09 fM, respectively. The stability and diffusion control analyses were performed as well. In both label‐free and labeled methods, the modified electron showed high selectivity for miRNA‐128. The use of methylene blue as a safer redox mediator caused miRNA‐128 to be detected with greater accuracy at low potentials in PBS media. The findings also show the substantial improvement in detection limit and linearity by using reduced graphene oxide‐magnetite‐gold nanoparticles that can be verified by comparing with previous studies on the detection of other miRNAs. 相似文献
63.
V. V. Annenkov A. S. Levina E. N. Danilovtseva E. A. Filina E. A. Mikhaleva V. F. Zarytova 《Russian Journal of Bioorganic Chemistry》2006,32(5):460-467
A new type of coating for manufacturing DNA chips was constructed on the basis of an organicinorganic nanocomposite based on the polyvinylbutyral-tetraethoxysilane copolymer. The organosilicon composite was functionalized by introduction of ethanolamine vinyl ether copolymers, which contain amino groups and anchor vinyloxide units capable of reacting with silanol groups of the nanocomposite. The resulting coatings form a film on glass slides with a high surface density of amino groups (up to 700 groups/nm2) suitable for three-dimensional immobilization of oligonucleotides. The use of bifunctional reagents (e.g., phenylene diisothiocyanate) for the attachment of oligonucleotides bearing amino linkers to the amino-containing surface provides an immobilization density of 0.5–1.6 pmol/mm2. Immobilization with a higher density (10–12 pmol/mm2) was achieved for attachment to amino-containing glass slides upon the use of oligonucleotides containing a selectively activated terminal phosphate group. The activation of oligonucleotides was carried out with the triphenylphosphine-dithiodipyridine pair in the presence of dimethylaminopyridine N-oxide. The resulting DNA chips were shown to be useful in principle for DNA detection. 相似文献
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B. N. Swathi B. R. Radha Krushna B. Daruka Prasad S. C. Sharma Balanehru Subramanian H. Nagabhushana 《Luminescence》2023,38(3):232-249
Latent fingerprints (LFPs) are one among the most important types of evidences at crime scenes because of the distinctiveness and tenacity of the friction ridges in fingerprints (FPs). Therefore, it is essential in forensic science to develop a reliable method to detect LFPs. Traditional detection methods still face a number of difficulties, such as limited sensitivity, low contrast, strong background, and complex processing stages. In this study, MgO-ZrO2:Tb3+ (1–5 mol%) (MZ:Tb) nanocomposites (NCs) were prepared via a simple solution combustion (SC) method at low temperature. The photoluminescence (PL) investigation demonstrates that when excited at 379 nm, the produced NCs emits distinctive emission peaks of terbium ions (Tb3+). According to the photometric results, the NCs can be employed as warm light NCs and emit light in the green portion of the colour spectrum. The estimated optical band gap from diffuse reflectance spectra is found to be in the range 4.84–4.97 eV. Regardless of the type of surface being used, the optimized MgO-ZrO2:Tb3+ (4 mol%) (MZ:4Tb) NCs has a strong ability to minimize background fluorescence interference. With high contrast LFP and I–V type of cheiloscopy, these NCs present a flexible fluorescent mark for the identification of levels 1–3 details in forensic investigation. 相似文献
66.
D Leštan M Leštan R T Lamar 《Journal of industrial microbiology & biotechnology》1998,20(3-4):244-250
The viability of mycelial fragments of Trametes versicolor and Irpex lacteus and their growth on selected hydrogels are described. The size of mycelial fragments of the fungi did not significantly influence
their viability. Alginate hydrogel films supported fungal growth better than agarose, carrageenan, chitosan and gelatin films,
and had the highest mechanical strength but were less hydrophilic than the other hydrogels. All commercial alginates that
were tested supported aseptic growth of fungal fragments without prior sterilization of the hydrogel solution. The viability
of mycelial fragments in the hydrogel solutions was higher for some commercial alginates than that in laboratory grade alginate.
The mechanical strength and hydrophilicity of hydrogels from alginate type Sobalg FD 155 and Meer HV were comparable to that
of laboratory grade alginate. Sterilization and pH of the alginate hydrogel did not significantly influence the growth of
T. versicolor mycelial fragments but affected the growth of I. lacteus. Concentrations of alginate in the range of 1–2% in the hydrogel did not affect the growth of entrapped mycelial fragments
of these fungi.
Received 25 June 1997/ Accepted in revised form 07 March 1998 相似文献
67.
Proton fluctuations reporting local motions of the glycosidic linkages of chemically crosslinked dextran hydrogels with well defined pore-size distributions are studied by static and dynamic neutron-scattering approaches. The dependence of the dynamic behaviour of water on the pore sizes is also discussed. 相似文献
68.
Electrocatalysis: Ultrafine Pt Nanoparticle‐Decorated Pyrite‐Type CoS2 Nanosheet Arrays Coated on Carbon Cloth as a Bifunctional Electrode for Overall Water Splitting (Adv. Energy Mater. 24/2018) 下载免费PDF全文
69.
Circular dichroism studies of low molecular weight hydrogelators: The use of SRCD and addressing practical issues 下载免费PDF全文
Efstratios D. Sitsanidis Carmen C. Piras Bruce D. Alexander Giuliano Siligardi Tamás Jávorfi Andrew J. Hall Alison A. Edwards 《Chirality》2018,30(6):708-718
Circular dichroism (CD) spectroscopy has been used extensively for the investigation of the conformation and configuration of chiral molecules, but its use for evaluating the mode of self‐assembly in soft materials has been limited. Herein, we report a protocol for the study of such materials by electronic CD spectroscopy using commercial/benchtop instruments and synchrotron radiation (SR) using the B23 beamline available at Diamond Light Source. The use of the B23 beamtime for SRCD was advantageous because of the unique enhanced spatial resolution achieved because of its highly collimated and small beamlight cross section (ca. 250 μm) and higher photon flux in the far UV region (175‐250 nm) enhancing the signal‐to‐noise ratio relative to benchtop CD instruments. A set of low molecular weight (LMW) hydrogelators, comprising two Fmoc‐protected enantiomeric monosaccharides and one Fmoc dipeptide (Fmoc‐FF), were studied. The research focused on the optimization of sample preparation and handling, which then enabled the characterization of sample conformational homogeneity and thermal stability. CD spectroscopy, in combination with other spectroscopic techniques and microscopy, will allow a better insight into the self‐assembly of chiral building blocks into higher order structural architectures. 相似文献
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Electrochemical monitoring of aflatoxin M1 in milk samples using silver nanoparticles dispersed on α‐cyclodextrin‐GQDs nanocomposite 下载免费PDF全文
Rana Shadjou Mohammad Hasanzadeh Mohammad Heidar‐poor Nasrin Shadjou 《Journal of molecular recognition : JMR》2018,31(6)
Aflatoxins are potential food pollutants produced by fungi. One of important toxins is aflatoxin M1 (AFM1). A great deal of concern is associated with AFM1 toxicity. In the present study, an innovative electrochemical interface for quantitation of AFM1 based on ternary signal amplification strategy was fabricated. In this work, silver nanoparticles was electrodeposited onto green and biocompatible nanocomposite containing α‐cyclodextrin as conductive matrix and graphene quantum dots as amplification element. Therefore, a multilayer film based on α‐cyclodextrin, graphene quantum dots, and silver nanoparticles was exploited to develop a highly sensitive electrochemical sensor for detection of AFM1. Fully electrochemical methodology was used to prepare a transducer on a glassy carbon electrode, which provided a high surface area toward sensitive detection of AFM1. The surface morphology of electrode surface was characterized by high‐resolution field emission scanning electron microscope. The proposed sensing platform provides a simple tool for AFM1 detection. Under optimized condition, the calibration curve for AFM1 concentration was linear in 0.015mM to 25mM with low limit of quantification of 2μM. The practical analytical utility of the modified electrode was illustrated by determination of AFM1 in unprocessed milk samples. 相似文献