Co-reporter:Yi Deng, Xiaohong Zhang, Yinghui Zhao, Shangshang Liang, Anxiu Xu, Xiang Gao, Feng Deng, Jing Fang, Shicheng Wei
Carbohydrate Polymers 2014 Volume 101() pp:36-39
Publication Date(Web):30 January 2014
DOI:10.1016/j.carbpol.2013.09.030
•The peptide-decorated PVA/HA polysaccharide nanofiber was successfully fabricated.•The PVA/HA nanofibers supported the adhesion and proliferation of hiPSCs.•Cell differentiation was enhanced by the peptide-decorated PVA/HA nanofibers.•The nanofibers provide well-defined conditions for hiPSCs growth and differentiation.Realization of the full potential of human induced pluripotent stem cells (hiPSCs) in clinical applications requires development of well-defined conditions for their growth and differentiation. A novel fully defined polyvinyl alcohol/hyaluronan (PVA/HA) polysaccharide nanofiber was developed for hiPSCs culture in commercially available xeno-free, chemically defined medium. Vitronectin peptide (VP) was immobilized to PVA/HA nanofibers through NHS/EDC chemistry. The hiPSCs successfully grew and proliferated on the VP-decorated PVA/HA nanofibers, similar to those on Matrigel™. Such well-defined, xeno-free and safe nanofiber substrate that supports culture of hiPSCs will not only help to accelerate the translational perspectives of hiPSCs, but also provide a platform to investigate the cell–nanofiber interaction mechanisms that regulate stem cell proliferation and differentiation.
Co-reporter:Y. Deng, X. Zhang, X. Zhao, Q. Li, Z. Ye, Z. Li, Y. Liu, Y. Zhou, H. Ma, G. Pan, D. Pei, J. Fang, S. Wei
Acta Biomaterialia 2013 Volume 9(Issue 11) pp:8840-8850
Publication Date(Web):November 2013
DOI:10.1016/j.actbio.2013.07.017
Abstract
Realization of the full potential of human induced pluripotent stem cells (hiPSC) in clinical applications requires the development of well-defined culture conditions for their long-term growth and directed differentiation. This paper describes a novel fully defined synthetic peptide-decorated substrate that supports self-renewal of hiPSC in commercially available xeno-free, chemically defined medium. The Au surface was deposited by a poly(OEGMA-co-HEMA) film, using the surface-initiated polymerization method (SIP) with the further step of carboxylation. The hiPSC generated from umbilical cord mesenchymal cells were successfully cultured for 10 passages on the peptide-tethered poly(OEGMA-co-HEMA) brushes for the first time. Cells maintained their characteristic morphology, proliferation and expressed high levels of markers of pluripotency, similar to the cells cultured on Matrigel™. Moreover, the cell adhesion could be tuned by the pattern and peptide concentration on the substrate. This well-defined, xeno-free and safe substrate, which supports long-term proliferation and self-renewal of hiPSC, will not only help to accelerate the translational perspectives of hiPSC, but also provide a platform to elucidate the underlying molecular mechanisms that regulate stem cell proliferation and differentiation via SIP technology.
Co-reporter:Xixue Hu, Hong Shen, Kegang Shuai, Enwei Zhang, Yanjie Bai, Yan Cheng, Xiaoling Xiong, Shenguo Wang, Jing Fang, Shicheng Wei
Applied Surface Science 2011 Volume 257(Issue 6) pp:1813-1823
Publication Date(Web):1 January 2011
DOI:10.1016/j.apsusc.2010.08.082
Abstract
Since metallic biomaterials used for orthopedic and dental implants possess a paucity of reactive functional groups, bioactivity modification of these materials is challenging. In the present work, the titanium discs and rods were treated with carbon dioxide plasma and then incubated in a modified simulated body fluid 1.5SBF to obtain a hydroxyapatite layer. Surface hydrophilicity of samples, changes of surface chemistry, surface morphologies of samples, and structural analysis of formed hydroxyapatite were investigated by contact angle to water, X-ray photoelectron spectrometer (XPS), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The results demonstrated that hydrophilicity of titanium surface was improved and hydroxyl groups increased after modification with carbon dioxide plasma treatment. The hydroxyl groups on the surface of titanium were the richest after carbon dioxide plasma treatment under the condition of 20 W for less than 30 s. The hydroxyapatite formability of titanium surface was enhanced by carbon dioxide plasma pretreatment, which was attributed to the surface chemistry. MC3T3-E1 cell as a model cell was cultured on the Ti, CPT-Ti and CPT/SBF-Ti discs in vitro, and the results of the morphology and differentiation of the cell showed that CPT/SBF-Ti was the highest bioactive. The relative parameters of the new bone around the Ti and CPT/SBF-Ti rods including bone mineral density (BMD), a ratio of bone volume to total volume (BV/TV), trabecular thickness (Tb.Th.) and trabecular number (Tb.N.) were analyzed by a micro-computed tomography (micro-CT) after 4-, 8- and 12-week implantation periods in vivo. The results indicated that the CPT/SBF-Ti was more advantageous for new bone formation.
Co-reporter:Xixue Hu, Hong Shen, Yan Cheng, Xiaoling Xiong, Shenguo Wang, Jing Fang, Shicheng Wei
Surface and Coatings Technology 2010 205(7) pp: 2000-2006
Publication Date(Web):
DOI:10.1016/j.surfcoat.2010.08.088
Co-reporter:M. Li, J. Zhang, C.Y. Xiong, J. Fang, J. M Li, Y. Hao
Optics and Lasers in Engineering 2005 Volume 43(Issue 8) pp:856-868
Publication Date(Web):August 2005
DOI:10.1016/j.optlaseng.2004.09.003
By digital correlation processing of Scanning electronic microscopy (SEM) images, the paper presents the deformation and damage analysis of an energetic material—the plastic-bonded explosive (PBX) on mesoscopic scale. The analysis is made by observing the deformation field resulted from the digital image correlation (DIC) processing of the images corresponding to the loading steps and comparing with the surface profiles of the composite material so as to visualize the matter damage near a preset crack. The results show that the local deformation disturbance can reveal the material damage even happened underneath the specimen surface. The strain distribution in the front of the preset crack, can be used to predict the propagating route of the microcrack initiated from the tip of the pre-crack, which is related to the splitting fracture of the granular-based composite under compressive loading.
Co-reporter:Hongyang Yuan, Xing Lv, Xiaohai Ma, Rui Zhang, Youyi Fu, Xuedong Yang, Xiaoying Wang, Zhaoqi Zhang, Jue Zhang, Jing Fang
Magnetic Resonance Imaging (January 2013) Volume 31(Issue 1) pp:150-155
Publication Date(Web):1 January 2013
DOI:10.1016/j.mri.2012.06.032
The purpose of this study was to develop a novel intravascular loopless monopole antenna (ILMA) design specifically for imaging of small vessel walls. The ILMA consisted of an unshielded, low-friction guide wire and a tuning/matching box. The material of the guide wire was nitinol and it was coated with polyurethane. Because the guide wire was unshielded, it could be made thinner than the coaxial cable-based loopless intravascular antenna design. The material of the box was aluminum. In this study, the diameter of the guide wire was 0.5 mm and the length was 58.7 mm. The ILMA was used as a receiving antenna and body coil for transmission. To verify the feasibility of the ILMA, in vitro and in vivo experiments were performed on a 3.0-T magnetic resonance (MR) scanner. In vitro tests using the ILMA indicated that the proposed design could be used to image target vessel walls with a spatial resolution of 313 μm at the frequency coding direction and more than 100 mm of longitudinal coverage. In vivo tests demonstrated that the images showed the vessel walls clearly by using the ILMA and also indicated that the ILMA could be used for small vessels. The proposed antenna may therefore be utilized to promote MR-based diagnoses and therapeutic solutions for cardiovascular atherosclerotic diseases.
