title: Mechanical sensing of the penetration of various nanoneedles into a living cell using atomic force microscopy.
abstract: Mechanical responses during insertion of a silicon nanoneedle into a living melanocyte were observed by using an atomic force microscope (AFM). In order to study the dependence of the mechanical response on the shape of the nanoneedle, we prepared various shapes of silicon AFM tips by focused-ion beam (FIB) etching. The force curves showed increases up to 0.65-1.9 nN after contact on the cell surface, and then the force dropped corresponding with the penetration of the needle through the cell membrane. The force required for penetration was significantly smaller than that using a normal pyramidal tip. The force curves with a cylindrical tip showed a shorter indenting distance before penetration than that with the cone-shaped tip. It is considered that the information about the geometry of penetrating material leads to the development of more suitable micro- and nano-materials to insert into a living cell for cell surgery.
authors.affiliation: Research Institute for Cell Engineering (RICE), National Institute of Advanced Industrial Science and Technology (AIST), 3-11-46 Nakoji, Amagasaki, Hyogo 661-0974, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Obataya
authors.forename: Chikashi
authors.initials: C
authors.lastname: Nakamura
authors.forename: SungWoong
authors.initials: S
authors.lastname: Han
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Nakamura
authors.forename: Jun
authors.initials: J
authors.lastname: Miyake
mesh_terms: D002478:Cells, Cultured; D004548:Elasticity; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008544:Melanocytes / Q000502:physiology* / Q000648:ultrastructure*; D008845:Microinjections / Q000295:instrumentation / Q000379:methods*; D008846:Micromanipulation / Q000295:instrumentation / Q000379:methods*; D018625:Microscopy, Atomic Force / Q000379:methods*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D009339:Needles; D013314:Stress, Mechanical