title: Biodistribution of neural stem cells after intravascular therapy for hypoxic-ischemia.
abstract: OBJECTIVE
  Intravascular transplantation of neural stem cells represents a minimally invasive therapeutic approach for the treatment of central nervous system diseases. The cellular biodistribution after intravascular injection needs to be analyzed to determine the ideal delivery modality. We studied the biodistribution and efficiency of targeted central nervous system delivery comparing intravenous and intra-arterial (IA) administration of neural stem cells after brain ischemia.
  
  
  METHODS
  Mouse neural stem cells were transduced with a firefly luciferase reporter gene for bioluminescence imaging (BLI). Hypoxic-ischemia was induced in adult mice and reporter neural stem cells were transplanted IA or intravenous at 24 hours after brain ischemia. In vivo BLI was used to track transplanted cells up to 2 weeks after transplantation and ex vivo BLI was used to determine single organ biodistribution.
  
  
  RESULTS
  Immediately after transplantation, BLI signal from the brain was 12 times higher in IA versus intravenous injected animals (P<0.0001). After IA injection, 69% of the total luciferase activity arose from the brain early after transplantation and 93% at 1 week. After intravenous injection, 94% of the BLI signal was detected in the lungs (P=0.004) followed by an overall 94% signal loss at 1 week, indicating lack of cell survival outside the brain. Ex vivo single organ analysis showed a significantly higher BLI signal in the brain than in the lungs, liver, and kidneys at 1 week (P<0.0001) and 2 weeks in IA (P=0.007).
  
  
  CONCLUSIONS
  IA transplantation results in superior delivery and sustained presence of neural stem cells in the ischemic brain in comparison to intravenous infusion.
authors.affiliation: Department of Neurosurgery, Stanford University, School of Medicine, Stanford, CA 94305-5327, USA.
authors.forename: Arjun V
authors.initials: AV
authors.lastname: Pendharkar
authors.forename: Josh Y
authors.initials: JY
authors.lastname: Chua
authors.forename: Robert H
authors.initials: RH
authors.lastname: Andres
authors.forename: Nancy
authors.initials: N
authors.lastname: Wang
authors.forename: Xavier
authors.initials: X
authors.lastname: Gaeta
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Abhijit
authors.initials: A
authors.lastname: De
authors.forename: Raymond
authors.initials: R
authors.lastname: Choi
authors.forename: Shawn
authors.initials: S
authors.lastname: Chen
authors.forename: Brian K
authors.initials: BK
authors.lastname: Rutt
authors.forename: Sanjiv S
authors.initials: SS
authors.lastname: Gambhir
authors.forename: Raphael
authors.initials: R
authors.lastname: Guzman
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002452:Cell Count; D002478:Cells, Cultured; D005434:Flow Cytometry; D020925:Hypoxia-Ischemia, Brain / Q000628:therapy*; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D051379:Mice; D009474:Neurons / Q000637:transplantation*; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000378:metabolism*; D014018:Tissue Distribution; D014161:Transduction, Genetic