title: Tracking of cell nuclei for assessment of in vitro uptake kinetics in ultrasound-mediated drug delivery using fibered confocal fluorescence microscopy.
abstract: OBJECTIVE
  Previously, we demonstrated the feasibility to monitor ultrasound-mediated uptake of a cell-impermeable model drug in real time with fibered confocal fluorescence microscopy. Here, we present a complete post-processing methodology, which corrects for cell displacements, to improve the accuracy of pharmacokinetic parameter estimation.
  
  
  METHODS
  Nucleus detection was performed based on the radial symmetry transform algorithm. Cell tracking used an iterative closest point approach. Pharmacokinetic parameters were calculated by fitting a two-compartment model to the time-intensity curves of individual cells.
  
  
  RESULTS
  Cells were tracked successfully, improving time-intensity curve accuracy and pharmacokinetic parameter estimation. With tracking, 93 % of the 370 nuclei showed a fluorescence signal variation that was well-described by a two-compartment model. In addition, parameter distributions were narrower, thus increasing precision.
  
  
  CONCLUSIONS
  Dedicated image analysis was implemented and enabled studying ultrasound-mediated model drug uptake kinetics in hundreds of cells per experiment, using fiber-based confocal fluorescence microscopy.
authors.affiliation: Imaging Division, University Medical Center Utrecht, Heidelberglaan 100, P.O. Box 85500, 3508 GA, Utrecht, Netherlands.
authors.forename: Marc
authors.initials: M
authors.lastname: Derieppe
authors.forename: Baudouin Denis
authors.initials: BD
authors.lastname: de Senneville
authors.forename: Hugo
authors.initials: H
authors.lastname: Kuijf
authors.forename: Chrit
authors.initials: C
authors.lastname: Moonen
authors.forename: Clemens
authors.initials: C
authors.lastname: Bos
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism*; D058948:Cell Tracking / Q000379:methods*; D016503:Drug Delivery Systems / Q000379:methods*; D007700:Kinetics; D018613:Microscopy, Confocal / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000379:methods*; D051381:Rats; D012815:Signal Processing, Computer-Assisted; D014465:Ultrasonics