title: In vivo dendritic cell tracking using fluorescence lifetime imaging and near-infrared-emissive polymersomes.
abstract: OBJECTIVE
  Noninvasive in vivo cell-tracking techniques are necessary to advance the field of cellular-based therapeutics as well as to elucidate mechanisms governing in vivo cell biology. Fluorescence is commonly used for in vitro and postmortem biomedical studies but has been limited by autofluorescence at the whole-animal level.
  
  
  METHODS
  In this report, we demonstrate the ability of in vivo fluorescent lifetime imaging to remove autofluorescence and thereby enable in vivo dendritic cell tracking in naïve mice. Specifically, we track mature dendritic cells (DCs) labeled internally with near-infrared-emissive polymersomes (NIR-DCs).
  
  
  RESULTS
  We establish the ability to detect labeled cells in vivo and image NIR-DC trafficking after both intravenous and subcutaneous delivery. In addition, we demonstrate the longitudinal capacity of this method by characterizing NIR-DC migration kinetics in the popliteal lymph node.
  
  
  CONCLUSIONS
  This work provides a tool to evaluate dendritic-cell-based immunotherapy and generates novel opportunities for in vivo fluorescence imaging.
authors.affiliation: Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, 210 S. 33rd Street Room 240 Skirkanich Hall, Philadelphia, PA 19104, USA.
authors.forename: Natalie A
authors.initials: NA
authors.lastname: Christian
authors.forename: Fabian
authors.initials: F
authors.lastname: Benencia
authors.forename: Michael C
authors.initials: MC
authors.lastname: Milone
authors.forename: Guizhi
authors.initials: G
authors.lastname: Li
authors.forename: Paul R
authors.initials: PR
authors.lastname: Frail
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Therien
authors.forename: George
authors.initials: G
authors.lastname: Coukos
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Hammer
mesh_terms: D000818:Animals; D002465:Cell Movement; D003584:Cytological Techniques / Q000295:instrumentation / Q000379:methods*; D003713:Dendritic Cells / Q000166:cytology*; D003952:Diagnostic Imaging / Q000295:instrumentation / Q000379:methods*; D005453:Fluorescence; D007700:Kinetics; D008198:Lymph Nodes / Q000166:cytology; D008722:Methods; D051379:Mice; D012107:Research Design