title: Femtosecond laser-induced cell-cell surgical attachment.
abstract: OBJECTIVE
  Laser-induced cell-cell surgical attachment using femtosecond laser pulses is reported.
  
  
  METHODS
  We have demonstrated the ability to attach single cells using sub-10 femtosecond laser pulses, with 800 nm central wavelength delivered from a Ti:Sapphire laser. To check that the cells did not go through a cell-fusion process, a fluorescent dye Calcein AM was used to verify that the fluorescent dye did not migrate from a dyed cell to a non-dyed cell. The mechanical integrity of the attached joint was assessed using an optical tweezer.
  
  
  RESULTS
  Attachment of cells was performed without the induction of cell-cell fusion, with attachment efficiency of 95%, and while preserving the cells' viability. Cell-cell attachment was achieved by delivery of one to two trains of femtosecond laser pulses lasting 15 ms each.
  
  
  CONCLUSIONS
  Laser-induced ionization process led to an ultrafast reversible destabilization of the phospholipid layer of the cellular membrane. The inner cell membrane remained intact during the attachment procedure, and isolation of the cells' cytoplasm from the surrounding medium was obtained. A strong physical attachment between the cells was obtained due to the bonding of the membranes' ionized phospholipid molecules and the formation of a joint cellular membrane at the connection point. The cellular attachment technique, femtosecond laser-induced cell-cell surgical attachment, can potentially provide a platform for the creation of engineered tissue and cell cultures.
authors.affiliation: Department of Electrical and Computer Engineering, Ultrafast Photonics and Nano-Optics Laboratory, University of Alberta, Edmonton, AB, T6G 2V4, Canada.
authors.forename: Nir
authors.initials: N
authors.lastname: Katchinskiy
authors.forename: Roseline
authors.initials: R
authors.lastname: Godbout
authors.forename: Helly R
authors.initials: HR
authors.lastname: Goez
authors.forename: Abdulhakem Y
authors.initials: AY
authors.lastname: Elezzabi
mesh_terms: D002448:Cell Adhesion; D045744:Cell Line, Tumor; D002462:Cell Membrane; D002470:Cell Survival; D006801:Humans; D053844:Lasers, Solid-State; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods*
keywords: carbohydrate synthesis; cell welding; cell-fusion; engineered cell culture; engineered tissue; hemifusion; protein synthesis; tissue assembly; tissue welding; ultrafast