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71.
Shaocheng Wang Siyong Lin Bo Xue Chenyu Wang Nana Yan Yueyan Guan Yuntao Hu Xuejun Wen 《Molecules (Basel, Switzerland)》2022,27(4)
Background: This study aimed to develop an ultrathin nanofibrous membrane able to, firstly, mimic the natural fibrous architecture of human Bruch’s membrane (BM) and, secondly, promote survival of retinal pigment epithelial (RPE) cells after surface functionalization of fibrous membranes. Methods: Integrin-binding peptides (IBPs) that specifically interact with appropriate adhesion receptors on RPEs were immobilized on Bruch’s-mimetic membranes to promote coverage of RPEs. Surface morphologies, Fourier-transform infrared spectroscopy spectra, contact angle analysis, Alamar Blue assay, live/dead assay, immunofluorescence staining, and scanning electron microscopy were used to evaluate the outcome. Results: Results showed that coated membranes maintained the original morphology of nanofibers. After coating with IBPs, the water contact angle of the membrane surfaces varied from 92.38 ± 0.67 degrees to 20.16 ± 0.81 degrees. RPE cells seeded on IBP-coated membranes showed the highest viability at all time points (Day 1, p < 0.05; Day 3, p < 0.01; Days 7 and 14, p < 0.001). The proliferation rate of RPE cells on uncoated poly(ε-caprolactone) (PCL) membranes was significantly lower than that of IBP-coated membranes (p < 0.001). SEM images showed a well-organized hexa/polygonal monolayer of RPE cells on IBP-coated membranes. RPE cells proliferated rapidly, contacted, and became confluent. RPE cells formed a tight adhesion with nanofibers under high-magnification SEM. Our findings confirmed that the IBP-coated PCL membrane improved the attachment, proliferation, and viability of RPE cells. In addition, in this study, we used serum-free culture for RPE cells and short IBPs without immunogenicity to prevent graft rejection and immunogenicity during transplantation. Conclusions: These results indicated that the biomimic BM-IBP-RPE nanofibrous graft might be a new, practicable approach to increase the success rate of RPE cell transplantation. 相似文献
72.
Miji Yeom Hyanggi Ji Jongheon Shin Eunae Cho De-Hun Ryu Deokhoon Park Eunsun Jung 《Molecules (Basel, Switzerland)》2022,27(4)
Striae distensae (SD) or stretch marks are common linear scars of atrophic skin with disintegrating extracellular matrix (ECM) structures. Although fibroblasts contribute to the construction of ECM structure in SD, some studies have reported that mast cell degranulation causes the disruption of ECM in early SD lesions. Lagerstroemia indica flower (LIF) has traditionally been used in India as a diuretic. However, little is known about the effect and molecular action of Lagerstroemia indica flower extract (LIFE) on alleviating SD. This study evaluated the effects of LIFE on mast cell degranulation and the synthesis of ECM components in fibroblasts. LIFE inhibits the adhesion of rat basophilic leukemia (RBL) cells, RBL-2H3 on fibronectin (FN) and the expression of integrin, a receptor for FN, thereby reducing focal adhesion kinase (FAK) phosphorylation. In addition, LIFE attenuated the allergen-induced granules and cytokine interleukin 3 (IL-3) through the adhesion with FN. Moreover, the conditioned medium (CM) of activated mast cells decreases the synthesis of ECM components, and LIFE restores the abnormal expressions induced by activated mast cells. These results demonstrate that LIFE suppresses FN-induced mast cell activation and promotes the synthesis of ECM components in fibroblast, which indicates that LIFE may be a useful cosmetic agent for SD treatment. 相似文献
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76.
《Journal of Dispersion Science and Technology》2013,34(3-4):305-341
Abstract Plasma treatment of polymers encompasses a variety of plasma technologies and polymeric materials for a wide range of applications and dates back to at least the 1960s. In this article we provide a brief review of the United States patent literature on plasma surface modification technologies and a brief review of the scientific literature on investigations of the effects of plasma treatment, the nature of the plasma environment, and the mechanisms that drive the plasma–surface interaction. We then discuss low‐radio‐frequency capacitively coupled nitrogen plasmas and their characteristics, suggesting that they provide significant plasma densities and populations of reactive species for effective plasma treatments on a variety of materials, particularly when placing the sample surface in the cathode sheath region. We further discuss surface chemical characterization of treated polymers, including some results on polyesters treated in capacitively coupled nitrogen plasmas driven at 40 kHz. Finally, we connect plasma characterization with surface chemical analysis by applying a surface sites model to nitrogen uptake of poly(ethylene terephthalate) (PET) and poly(ethylene naphthalate) (PEN) treated in a 40 kHz nitrogen plasma. This example serves to suggest an interesting practical approach to comparisons of plasma treatments. In addition, it suggests an approach to defining the investigations required to conclusively identify the underlying treatment mechanisms. 相似文献
77.
Oxidation of four typical lead frame copper alloys was investigated. The oxidation rate and adhesion strength of oxide films
to copper alloy substrates were studied by measuring the thickness and carrying out peel tests. The results show that, although
copper alloys C5191 and C7025 have thinner oxide films, a lower adhesion strength and a higher proportion of CuO were obtained
than in the other copper alloys EFTEC64T and C194. The adhesion strength is mainly influenced by the structure of the oxide
film of the copper alloys, especially the CuO/Cu2O ratio in the film. The highest adhesion strength is obtained for the copper oxide film with a basic structure of CuO/Cu2O/Cu and a CuO/Cu2O ratio of about 0.1. The segregation of additional elements in the copper alloy plays an important role in the oxide film
structure. 相似文献
78.
David R. Harding Holly Goodrich Aaron Caveglia Mitchell Anthamatten 《Journal of Polymer Science.Polymer Physics》2014,52(14):936-945
Knowing the mechanical properties of UV‐curable resins at cryogenic conditions is important to ongoing fusion‐energy research and to emerging aerospace applications. The tensile and interfacial shear strengths of two commercially available UV‐curable resins were measured at room‐temperature and cryogenic conditions for both bulk and reduced (subnanoliter) specimen volumes. The tensile properties of cured specimens are remarkably sensitive to both testing temperature and specimen size. For one type of resin, the cold (?150 °C) tensile strength of subnanoliter specimens is ~9× larger (179 ± 19 MPa) than bulk values at room temperature. The interfacial shear strength between SiC fibers and small volumes of resin volumes is comparable to the bulk, room‐temperature tensile strength, but it varies over a wide range at ?150 °C (15–53 MPa). All resins were fully cured, and an analysis of fractured surfaces revealed microstructural features. The enhanced strength in microscopic specimens may be related to inhomogeneous stress fields that develop during cure. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 936–945 相似文献
79.
The reliability of adhesion strength of the Sn-9Zn-1.5Ag-0.5Bi/Cu during isothermal aging has been investigated. Due to the
growth and decomposition of the intermetallic compound (IMC), the adhesion strength varies with aging at 150°C from 100, 400,
and 700–1,000 h as wetted at 250°C for 60 sec. The IMC layers are determined at the Sn-9Zn-1.5Ag-0.5Bi/Cu interface by an
x-ray diffractometer (XRD), an optical microscope (OM), a scanning electron microscope (SEM), an energy-dispersive spectroscope
(EDS), and a transmission electron microscope (TEM). The adhesion strength has been investigated by the pull-off test. The
results show that the Cu6Sn5, Cu5Zn8, and Ag3Sn IMCs are identified at the Sn-9Zn-1.5Ag-0.5Bi/Cu interface as aging. The adhesion strengths are 12.44±0.58, 8.57±0.43,
5.50±0.78, 4.32±0.78, and 3.32±0.43 MPa for aging times of 0 h, 100 h, 400 h, 700 h, and 1,000 h, respectively. 相似文献
80.
本文根据加载激光的工艺参数以及薄膜、基体的材料特性,建立了薄膜与基体的有限元模型,对高斯激光在加载在薄膜表面后的温度场进行有限元模拟,获得膜基系统中温度随时间的变化关系以及薄膜界面结合处的温升规律。并在此基础上根据薄膜和基体的热膨胀性能,进行薄膜和基体的应力场模拟,获得了膜基系统的应力场随时间的变化关系。模拟结果表明:在激光加载过程中,薄膜和基体中的温度场随着时间增加,由于热传导系数的差异在薄膜和基体之间产生温差。在膜基系统中产生的应力场主要集中在薄膜内部,膜基界面结合处产生的应力较大会导致薄膜的脱粘。模拟结果定性地反映了薄膜和基体中温度和热应力的变化规律,为分析激光划痕法的作用过程提供了一定的理论依据,对研究膜基系统失效进程具有重要意义。 相似文献