title: Nanoneedle insertion into the cell nucleus does not induce double-strand breaks in chromosomal DNA.
abstract: An atomic force microscope probe can be formed into an ultra-sharp cylindrical shape (a nanoneedle) using micro-fabrication techniques such as focused ion beam etching. This nanoneedle can be effectively inserted through the plasma membrane of a living cell to not only access the cytosol, but also to penetrate through the nuclear membrane. This technique shows great potential as a tool for performing intranuclear measurements and manipulations. Repeated insertions of a nanoneedle into a live cell were previously shown not to affect cell viability. However, the effect of nanoneedle insertion on the nucleus and nuclear components is still unknown. DNA is the most crucial component of the nucleus for proper cell function and may be physically damaged by a nanoneedle. To investigate the integrity of DNA following nanoneedle insertion, the occurrence of DNA double-strand breaks (DSBs) was assessed. The results showed that there was no chromosomal DNA damage due to nanoneedle insertion into the nucleus, as indicated by the expression level of γ-H2AX, a molecular marker of DSBs.
authors: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-26 Naka-cho, Koganei, Tokyo 184-8588, Japan.
authors: Seunghwan
authors: S
authors: Ryu
authors: Ryuzo
authors: R
authors: Kawamura
authors: Ryohei
authors: R
authors: Naka
authors: Yaron R
authors: YR
authors: Silberberg
authors: Noriyuki
authors: N
authors: Nakamura
authors: Chikashi
authors: C
authors: Nakamura
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000235:genetics / Q000528:radiation effects; D002470:Cell Survival; D002875:Chromosomes / Q000235:genetics / Q000528:radiation effects; D004247:DNA / Q000528:radiation effects; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects; D018625:Microscopy, Atomic Force / Q000295:instrumentation*; D049329:Nanostructures; D014466:Ultraviolet Rays
chemical_list: D004247:DNA
keywords: Atomic force microscope; Cell nucleus; Double-strand breaks; Nanoneedle; UV-irradiation; γ-H2AX