title: Biologic properties of gadolinium diethylenetriaminepentaacetic acid-labeled and PKH26-labeled human umbilical cord mesenchymal stromal cells.
abstract: OBJECTIVE
  This study was conducted to characterize gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA)-labeled and PKH26-labeled human umbilical cord mesenchymal stromal cells (HuMSCs) and to track them with magnetic resonance imaging (MRI) in vitro and in vivo.
  
  
  METHODS
  HuMSCs were isolated from umbilical cords and expanded in vitro. Cells were sequentially labeled with Gd-DTPA and PKH26. The labeling efficiency was determined by spectrophotometry measurements, and the longevity of Gd-DTPA maintenance was measured with MRI. The influence of double labeling on cellular biologic properties was assessed by cell proliferation, viability, differentiation, cycle and apoptosis. Transplantation of double-labeled HuMSCs or placebo was performed in 39 female Sprague-Dawley rats. Leak point pressure and maximal bladder capacity were measured in animals 6 weeks after injection.
  
  
  RESULTS
  The T1 values and signal intensity on T1-weighted imaging of labeled cells were significantly higher than the control group (P < 0.05). The signal intensity on T1-weighted imaging of labeled cells was retained >14 days in vitro and in vivo. There was no significant difference in the cell cycle, cell apoptosis, cell proliferation and cell viability between labeled and unlabeled HuMSCs (P > 0.05). After double labeling, HuMSCs were still capable of differentiating into osteoblasts and adipocytes. Periurethrally injected HuMSCs in the rats significantly improved leak point pressure and maximal bladder capacity.
  
  
  CONCLUSIONS
  HuMSCs were successfully labeled with Gd-DTPA and PKH26. This labeling method is reliable and efficient and can be applied for tracking cells in vitro and in vivo without altering cellular biologic properties.
authors.affiliation: Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou, Gansu Province, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Pan
authors.affiliation: Department of Gynaecology, Lanzhou University Second Hospital, Lanzhou, Gansu Province, China. Electronic address: yanjiusheng666@yahoo.com.cn.
authors.forename: Jianfa
authors.initials: J
authors.lastname: Lan
authors.affiliation: Department of Gynecology and Obstetrics, First Affiliated Hospital Jinan University, Guangzhou, Guangdong Province, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Luo
authors.affiliation: Department of Gynaecology, Lanzhou University Second Hospital, Lanzhou, Gansu Province, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Gao
authors.affiliation: Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou, Gansu Province, China. Electronic address: xdxie@lzu.edu.cn.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Xie
authors.affiliation: Department of Gynaecology, Lanzhou University Second Hospital, Lanzhou, Gansu Province, China.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Guo
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D058948:Cell Tracking; D005260:Female; D019786:Gadolinium DTPA / Q000009:adverse effects / Q000737:chemistry / Q000627:therapeutic use; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects; D009930:Organic Chemicals / Q000009:adverse effects / Q000737:chemistry / Q000627:therapeutic use; D051381:Rats; D013194:Staining and Labeling; D014470:Umbilical Cord / Q000166:cytology*
chemical_list: D009930:Organic Chemicals; C070080:PKH 26; D019786:Gadolinium DTPA
keywords: Gd-DTPA; HuMSCs; MRI; PKH26; cell labeling