title: Positive-contrast cellular MRI of embryonic stem cells for tissue regeneration using a highly efficient T1MRI contrast agent.
abstract: To investigate the feasibility of high-sensitivity cellular MRI of embryonic stem (ES) cells using a novel cell permeable and cell retentive T1contrast agent.
  
  
  
  Mouse ES cells were labeled with a novel manganese porphyrin contrast agent, MnAMP, at 0.1 mM over 2 to 24 h and retained in contrast-free medium for up to 24 h postlabeling. MRI was performed on a 3 Tesla clinical scanner; T1and T2relaxation times were measured. Quantification of manganese content was performed using atomic absorption spectroscopy. Viability and proliferation assays were done for the longest labeling interval. Differentiation capacity was assessed using the hanging drop method to direct differentiation toward cardiomyocytes.
  
  
  
  MnAMP-labeled ES cells exhibited over a fourfold decrease in T1compared with unlabeled cells, and maintained up to a threefold decrease 24 h postlabeling. Viability and proliferation were not affected. Most importantly, labeled ES cells differentiated into functional cardiomyocytes that exhibited normal contractility patterns.
  
  
  
  MnAMP-based cellular MRI is a very high sensitivity T1approach for cellular imaging. It has the potential for noninvasive in vivo monitoring of stem cell therapy in cardiac regeneration and other tissue engineering and regenerative medicine applications. J. Magn. Reson. Imaging 2016;44:1456-1463.
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.|Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, Canada.|Department of Chemical Engineering and Bioengineering, McMaster University, Hamilton, ON, Canada.
authors.forename: Sadi
authors.initials: S
authors.lastname: Loai
authors.affiliation: Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada.|Department of Chemistry, University of Toronto, Toronto, ON, Canada.
authors.forename: Inga
authors.initials: I
authors.lastname: Haedicke
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.|Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, Canada.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Mirzaei
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.|Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, Canada.|Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Simmons
authors.affiliation: Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada.|Department of Chemistry, University of Toronto, Toronto, ON, Canada.
authors.forename: Xiao-An
authors.initials: XA
authors.lastname: Zhang
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.|Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, Canada.|The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto Toronto, ON, Canada.
authors.forename: Hai Ling
authors.initials: HL
authors.lastname: Cheng
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D058948:Cell Tracking / Q000379:methods*; D003287:Contrast Media / Q000737:chemistry; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000637:transplantation*; D005240:Feasibility Studies; D048091:Guided Tissue Regeneration / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008345:Manganese / Q000737:chemistry*; D051379:Mice; D032383:Myocytes, Cardiac / Q000166:cytology*; D011166:Porphyrins / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D011166:Porphyrins; D008345:Manganese
keywords: cardiomyocytes; cellular imaging and cell tracking; embryonic stem cells; regenerative medicine; stem cell therapy; tissue engineering