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21.
Evaluation of the chondrogenic differentiation of mesenchymal stem cells on hybrid biomimetic scaffolds 下载免费PDF全文
Hybrid materials are widely and promisingly used as scaffolds in cartilage tissue remodeling. In this study, hybrid scaffolds consist of polycaprolactone (PCL), poly(vinyl alcohol) (PVA) with/without gelatin (GEL) to mimic natural cartilage extracellular matrix (ECM) were investigated. Scaffolds were prepared by freeze drying and characterized by scanning electron microscopy and compressive mechanical testing. Biological assays of mesenchymal stem cell (MSC) cultures, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide, and dimethyl methylene blue were performed, and real‐time polymerization chain reaction analysis of the cartilage‐specific ECM gene marker expression was done. The results show an open interconnected porous structure with a compression modulus of 1.27 ± 0.04 MPa. The surface of the scaffolds showed an excellent efficiency in the adhesion and proliferation of MSCs. A significant increase in the proteoglycan content from 3.70 ± 0.96 to 5.4 ± 1.13 μg/mL was observed after 14 days in the PCL–PVA–GEL scaffolds. The expression amount of the sex‐determining region Y–Box 9 (SOX9) and collagen II (COL2) mRNA levels of the MSCs showed significant increases in SOX9 and COL2, respectively in comparison with PCL–PVA scaffold. The study revealed that the aforementioned scaffold as a blend of natural and synthetic polymers may be a promising substrate in tissue engineering for cartilage repair with MSC transplantation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40635. 相似文献
22.
S. Naddaf Dezfuli S. K. Sadrnezhaad M. A. Shokrgozar S. Bonakdar 《Journal of materials science. Materials in medicine》2012,23(10):2483-2488
Open-pore titanium scaffolds were fabricated by sintering of compressed mixtures of TiH1.924 and urea. Spherical and irregular shaped space holders were used to investigate the effect of pore shape on cellular behavior. After removal of the space holder, the shape of the spacers was replicated to the pores. Average diameter of the pores was in the range of 300–600?μm. SEM images showed that titanium hydride resulted in higher surface roughness and larger micro porosities than pure titanium. In vitro evaluations were carried out by using MTT assay, measuring alkaline phosphatase activity and alizarin red staining in flow perfusion bioreactor for cell culture. Observations revealed excellent attachment and proliferation of G-292 cells to the highly porous scaffolds fabricated with titanium hydride and urea of this research. 相似文献
23.
Maedehsadat Mousavi Zeinab Salehi Alireza Rezvanpour Mehdi Mosayebi Masoumeh Farahani Mohammad Asadi Tokmedash Mohammad Ali Shokrgozar 《加拿大化工杂志》2023,101(10):5482-5497
Smart drug delivery systems have attracted a lot of attention as one of the new treatment methods for cancer. In this study, a smart drug delivery system carrying anticancer drugs was obtained by the intelligent synthesis of glucosamine (GA)-functionalized graphene oxide (GO)-based iron oxide nanoparticles (Fe3O4@GO-GA) using Hummers and chemical co-precipitation processes. Nanohybrids have a high surface area (280.26 m2/g) and superparamagnetic behaviour (Ms = 26.017 emu/g), indicating a significant loading capacity (373.78 mg/mg) and efficiency (96.3%) for pharmaceutical loading. An adsorption study of conventional daunorubicin (DNR) on this carrier showed that the drug release is more prone to occur under acidic conditions (pH = 5.5), at moderately high temperatures (T = 40°C), and in the absence of smart carriers. The toxicity of the smart nanohybrids was examined using the sulphorhodamine B (SRB) assay in Michigan Cancer Foundation-7 (MCF-7) cell lines. The rate of death of cells exposed to smart drug-containing systems in comparison to the systems without GA shows that GA reduces the toxicity of Fe3O4@GO. 相似文献
24.
Linna
dborn Jnsson Maryam Sahi Ximena Lopez-Lorenzo Faye Leilah Keller Ourania N. Kostopoulou Nikolas Herold Lars hrlund-Richter Shahrzad Shirazi Fard 《International journal of molecular sciences》2021,22(7)
Most chemotherapeutics target DNA integrity and thereby trigger tumour cell death through activation of DNA damage responses that are tightly coupled to the cell cycle. Disturbances in cell cycle regulation can therefore lead to treatment resistance. Here, a comprehensive analysis of cell cycle checkpoint activation following doxorubicin (doxo) treatment was performed using flow cytometry, immunofluorescence and live-cell imaging in a panel of TP53 mutated ultra high-risk neuroblastoma (NB) cell lines, SK-N-DZ, Kelly, SK-N-AS, SK-N-FI, and BE(2)-C. Following treatment, a dose-dependent accumulation in either S- and/or G2/M-phase was observed. This coincided with a heterogeneous increase of cell cycle checkpoint proteins, i.e., phos-ATM, phos-CHK1, phos-CHK2, Wee1, p21Cip1/Waf1, and p27Kip among the cell lines. Combination treatment with doxo and a small-molecule inhibitor of ATM showed a delay in regrowth in SK-N-DZ, of CHK1 in BE(2)-C, of Wee1 in SK-N-FI and BE(2)-C, and of p21 in Kelly and BE(2)-C. Further investigation revealed, in all tested cell lines, a subset of cells arrested in mitosis, indicating independence on the intra-S- and/or G2/M-checkpoints. Taken together, we mapped distinct cell cycle checkpoints in ultra high-risk NB cell lines and identified checkpoint dependent and independent druggable targets. 相似文献
25.
Fariborz Atabaki Shahrzad Jahangiri 《Protection of Metals and Physical Chemistry of Surfaces》2021,57(4):820-833
Protection of Metals and Physical Chemistry of Surfaces - The achievement of high corrosion inhibition performances by manipulating the molecular structure of organic substances has gained much... 相似文献
26.
Drug Delivery: On‐Chip Fabrication of Paclitaxel‐Loaded Chitosan Nanoparticles for Cancer Therapeutics (Adv. Funct. Mater. 4/2014) 下载免费PDF全文
27.
Shahrzad Fadaie Mohammad Mehdi Kashani-Motlagh Amir Maghsoudipour Bita Faridnia 《Journal of Materials Science: Materials in Electronics》2013,24(3):974-978
Y2O3:Eu3+ nano phosphors (about 65 nm in size) were prepared via co-precipitation method by using co-polymer NIPAM/AAc as a template with narrow size distribution. The aim of the paper is to indicate the co-polymer influence on size and luminescence characteristics of nano phosphors. In this respect, phase content and morphology were characterized by X-ray diffraction and transmission electron microscopy. All the powders were well crystallized and the particles were clearly spherical with good dispersibility. Luminescence measurements were used to investigate the role of precursor in powders and the utmost luminescence intensity was observed at 4 mol% of Eu3+ while the quenching concentration of Eu3+ ions has occurred at 5 mol%. 相似文献
28.
29.
The effect of artificial aging on the compression yield strength of an open-cell AA6101 foam is studied using both experimental
and modeling approaches. Isothermal calorimetry is used to analyze the precipitation kinetics of the foam. The modeling work
combines the established approaches for predicting the yield strength of open-cell metallic foams as a function of the relative
density and normalized strength, as well as the age hardening behavior of AA6101 alloy. The foam yield strength is related
to the evolution of precipitate content during aging and is modeled for artificial aging at 180 and 220 °C. It is shown that
the model predictions match very well with the experimentally determined yield strength values. The overall results suggest
that the presented analytical and modeling approaches can effectively be used to predict the precipitation hardening behavior
and/or optimize processing and properties of AA6101 foams. 相似文献
30.
Ionic liquids (ILs) are often well‐known benign solvents capable of replacing conventional organic solvents, and they have become attractive solvents for many chemical reactions. Aromatic polyamides (PAs) have received particular interest in past years because of their high thermal and chemical resistance and their potential as high‐performance materials for different applications. In this investigation, the preparation of extended PAs derived from 5‐aminoisophthalic acid containing chiral pendent linkage (N‐phthaloyl‐L ‐leucine) with various aromatic diamines was studied. The bulky monomer 5‐(4‐methyl‐2‐phthalimidylpentanoylamino)isophthalic acid was prepared in three steps. Direct polyamidation of this monomer with several commercially available diamines in the presence of IL (1,3‐dipropylimidazolium bromide) and triphenyl phosphite gave novel PAs in good yields and inherent viscosities in the range of 0.38–0.55 dL g?1. Because of the existence of amino acid in this architect, the resulting polymers are optically active. All of these PAs showed good solubility and readily dissolved in many organic solvents. Characterization of all the products was performed by FTIR, specific rotation, and representative ones by 1H NMR, elemental analysis, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). TGA exhibited that two elite polymers were stable, with 10% weight loss recorded above 410 and 430°C in the nitrogen atmosphere. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献