title: The dependence of efficiency of transmembrane molecular transfer using electroporation on medium viscosity.
abstract: BACKGROUND
  In the present study, we aimed to evaluate the efficiency of drug and gene electrotransfer into cells in vitro depending on medium viscosity.
  
  
  METHODS
  Experiments were performed using Chinese hamster ovary cells. Efficiency of molecular electrotransfer depending of medium viscosity was evaluated using two different electroporation conditions: a high-voltage (HV) pulse and a combination of a high-voltage pulse and a low-voltage pulse (HV + LV). To evaluate the efficiency of molecular electrotransfer, anticancer drug bleomycin and two different plasmids coding for green fluorescent protein and luciferase were used.
  
  
  RESULTS
  We found that a slight increase in medium viscosity from 1.3-1.4 mPa·s significantly decreased the transfection efficiency, both in terms of transfected cells and total protein production, which was abolished completely with an increase in medium viscosity to 6.1 mPa·s. Notably, at this medium viscosity, electrotransfer of the small anticancer drug was still efficient. Using HV and HV + LV pulse combinations, we showed that a decrease of DNA electrotransfer, especially at lower medium viscosities, can be compensated for by the LV pulse to some extent. On the other hand, the addition of the LV pulse after the HV pulse did not have any positive effect on the efficiency of bleomycin electrotransfer.
  
  
  CONCLUSIONS
  These findings demonstrate that transfection is very susceptible to medium viscosity and highlights the importance of the electrophoretic component in experiments when a considerable transfection level is needed.
authors.affiliation: Biophysical Research Group, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania.|Emergency Department, Southampton General Hospital, University Hospital Southampton Foundation Trust (UHS), Southampton, UK.
authors.forename: Sandra
authors.initials: S
authors.lastname: Sungailaitė
authors.affiliation: Biophysical Research Group, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania.
authors.forename: Paulius
authors.initials: P
authors.lastname: Ruzgys
authors.affiliation: Biophysical Research Group, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania.
authors.forename: Ingrida
authors.initials: I
authors.lastname: Šatkauskienė
authors.affiliation: Biophysical Research Group, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania.
authors.forename: Karolina
authors.initials: K
authors.lastname: Čepurnienė
authors.affiliation: Biophysical Research Group, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania.
authors.forename: Saulius
authors.initials: S
authors.lastname: Šatkauskas
mesh_terms: D000818:Animals; D016466:CHO Cells; D002452:Cell Count; D002462:Cell Membrane / Q000378:metabolism*; D006224:Cricetinae; D003412:Cricetulus; D003470:Culture Media / Q000737:chemistry*; D004247:DNA / Q000378:metabolism; D004560:Electricity; D018274:Electroporation / Q000379:methods*; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins / Q000378:metabolism; D014783:Viscosity
chemical_list: D003470:Culture Media; D049452:Green Fluorescent Proteins; D004247:DNA
keywords: DNA electrotransfer; bleomycin; drug delivery; electroporation; transfection; viscosity