The cover describes the development of nanofibers with encapsulated growth factors has been emerged as a promising approach in neo-tissues applications. The proposed nanofibrous systems provide a novel approach to both simulate the extra-cellular matrix for cell adhesion and also for localized delivery of signaling molecules and growth factors. Growth factors could be loaded into nanofibers using different techniques including physical adsorption, covalent bonding or encapsulation.
Impact of infrared radiation on oxide layer of ultrathin TiNi-based alloy wire
Gunther Sergey1, Chekalkin Timofey1, 2*, Hodorenko Valentina1, Kang Ji-hoon2, Kim Ji-soon3, Gunther Victor1
1Research Institute of Medical Materials, Tomsk State University, ul. 19 Gv. Divizii 17, Tomsk, 634045, Russia
2Material Research Laboratory, Kang&Park Medical Co., 48 Jungsimsangeob-2 ro, Ochang-eub, 28119, S. Korea
3School of Material Science and Engineering, University of Ulsan, 93 Daehak-ro, Ulsan, 44610, S. Korea
Adv. Mater. Lett., 2018, 9 (10), pp 715-720
Publication Date (Web): Jul 18, 2018
Copyright © 2019 VBRI Press
Despite the well-known advantages of TiNi-based alloys, the cost of production is still high. The alloys are traditionally made by vacuum induction melting technology followed by vacuum arc remelting to get ingots which are further worked mechanically to final or semi-finished items. The special attention is paid by a thin wire which can be used as a suture material or for a tissue grafting. Thin TiNi yarns are produced by cold drawing via dies with the intermediate annealing. When a diameter is about or over 1 mm, the existing solutions give clear insight into a general idea about how to change the structure and properties of the alloy. However, when the size is definitely scaled-down to 90 μm and less, serious difficulties appear because such yarn requires thoroughly care in mechanical processing steps and repeated heat treatment increases the expense making the product costly and unprofitable. As working steps and heat treatment of the ultrathin TiNi-based wire (UW) are to be more predictable and controllable, there was suggested an infrared (IR) drawing heater due to the radial warming system located prior to the die. In hope to provide a more comprehensive understanding of this issue, a study on how the IR heating method influences on surface properties of the UW, comparing the various effects of heat treatment was carried out using the designed IR heater. The study covers the effect of oxide layer composition and its modification on the properties of the wire IR-heat drawn. Strong correlations were observed between oxide layer thickness and strength characteristic of the resultant wire. These findings elucidate the role of the oxide layer and its composition on a quality of the UW drawing process.
TiNi-based alloy, ultrathin wire, IR drawing, ductility, elemental analysis.