title: In vitro mesenchymal stem cell responses on laser-welded NiTi alloy.
abstract: The biocompatibility of NiTi after laser welding was studied by examining the in vitro (mesenchymal stem cell) MSC responses at different sets of time varying from early (4 to 12h) to intermediate phases (1 and 4 days) of cell culture. The effects of physical (surface roughness and topography) and chemical (surface Ti/Ni ratio) changes as a consequence of laser welding in different regions (WZ, HAZ, and BM) on the cell morphology and cell coverage were studied. The results in this research indicated that the morphology of MSCs was affected primarily by the topographical factors in the WZ: the well-defined and directional dendritic pattern and the presence of deeper grooves. The morphology of MSCs was not significantly modulated by surface roughness. Despite the possible initial Ni release in the medium during the cell culture, no toxic effect seemed to cause to MSCs as evidenced by the success of adhesion and spreading of the cells onto different regions in the laser weldment. The good biocompatibility of the NiTi laser weldment has been firstly reported in this study.
authors.affiliation: Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
authors.forename: C W
authors.initials: CW
authors.lastname: Chan
authors.forename: I
authors.initials: I
authors.lastname: Hussain
authors.forename: D G
authors.initials: DG
authors.lastname: Waugh
authors.forename: J
authors.initials: J
authors.lastname: Lawrence
authors.forename: H C
authors.initials: HC
authors.lastname: Man
mesh_terms: D002152:Calorimetry, Differential Scanning; D048430:Cell Shape; D002478:Cells, Cultured; D007368:Interferometry; D007834:Lasers; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000648:ultrastructure; D009532:Nickel / Q000494:pharmacology*; D056951:Photoelectron Spectroscopy; D013696:Temperature; D014025:Titanium / Q000494:pharmacology*; D014896:Welding
chemical_list: C040654:titanium nickelide; D009532:Nickel; D014025:Titanium
keywords: Fiber laser; Laser welding; Mesenchymal stem cell (MSC); NiTi; Shape memory alloy (SMA)