title: Non-invasive Macrophage Tracking Using Novel Porphysome Nanoparticles in the Post-myocardial Infarction Murine Heart.
abstract: We generated a folate-conjugated porphyrin nanoparticle (porphysome) suitable for multimodal non-invasive active macrophage tracking post-myocardial infarction (MI).
  
  
  
  Macrophage uptake of folate-conjugated porphysomes was selective. Folate-porphysome cardiac macrophage tracking was detected in vivo using radioligand and fluorescent imaging. To track post-MI macrophage mobilization, cardiac fluorescence signal in folate-porphysome-injected mice was measured for 9 day post-MI. Active macrophage phenotype was assessed using immunohistochemistry.
  
  
  
  Heart active macrophage presence peaked on day 1, returned to baseline by day 3, and peaked again on day 7 post-MI. Macrophages were distributed throughout the left ventricle at day 1, but aggregated within scar tissue at day 7. Macrophage phenotype was pro-inflammatory (TNFα(+)) at day 1, whereas scar-resident macrophages expressed anti-inflammatory markers (IL-10, TGFβ) at day 7. However, day 7 macrophages outside the scar expressed neither pro- nor anti-inflammatory markers.
  
  
  
  We established that folate-porphysomes are suitable for non-invasive imaging of macrophages and used it to investigate active macrophage behavior in the infarcted heart.
authors.affiliation: Division of Cardiovascular Surgery, Toronto General Research Institute, University Health Network, Toronto, Canada.
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Ni
authors.affiliation: Princess Margaret Cancer Center, University Health Network, Toronto, Canada.|Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada.
authors.forename: Cheng S
authors.initials: CS
authors.lastname: Jin
authors.affiliation: Princess Margaret Cancer Center, University Health Network, Toronto, Canada.|Medical Isotope Research Center, Peking University, Beijing, China.
authors.forename: Liyang
authors.initials: L
authors.lastname: Cui
authors.affiliation: Division of Cardiovascular Surgery, Toronto General Research Institute, University Health Network, Toronto, Canada.|Department of Ophthalmology, the Second Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Zhengbo
authors.initials: Z
authors.lastname: Shao
authors.affiliation: Division of Cardiovascular Surgery, Toronto General Research Institute, University Health Network, Toronto, Canada.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.affiliation: Division of Cardiovascular Surgery, Toronto General Research Institute, University Health Network, Toronto, Canada.
authors.forename: Shu-Hong
authors.initials: SH
authors.lastname: Li
authors.affiliation: Division of Cardiovascular Surgery, Toronto General Research Institute, University Health Network, Toronto, Canada.|Department of Surgery, Division of Cardiac Surgery, University of Toronto, Toronto, Canada.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Weisel
authors.affiliation: Princess Margaret Cancer Center, University Health Network, Toronto, Canada. gang.zheng@uhnres.utoronto.ca.|Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada. gang.zheng@uhnres.utoronto.ca.|MaRS Centre, Toronto Medical Discovery Tower, Room 3-702, 101 College St, Toronto, ON, M5G 1L7, Canada. gang.zheng@uhnres.utoronto.ca.
authors.forename: Gang
authors.initials: G
authors.lastname: Zheng
authors.affiliation: Division of Cardiovascular Surgery, Toronto General Research Institute, University Health Network, Toronto, Canada. renkeli@uhnresearch.ca.|Department of Surgery, Division of Cardiac Surgery, University of Toronto, Toronto, Canada. renkeli@uhnresearch.ca.|MaRS Centre, Toronto Medical Discovery Tower, Room 3-702, 101 College St, Toronto, ON, M5G 1L7, Canada. renkeli@uhnresearch.ca.
authors.forename: Ren-Ke
authors.initials: RK
authors.lastname: Li
mesh_terms: D000818:Animals; D058948:Cell Tracking / Q000379:methods*; D060833:Cellular Microenvironment; D005492:Folic Acid / Q000737:chemistry; D006321:Heart / Q000000981:diagnostic imaging*; D008262:Macrophage Activation; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000473:pathology*; D053758:Nanoparticles / Q000737:chemistry*; D010641:Phenotype; D011166:Porphyrins / Q000737:chemistry*; D000067996:RAW 264.7 Cells
chemical_list: D011166:Porphyrins; D005492:Folic Acid
keywords: Fluorescent imaging; Inflammation; Macrophage; Multimodal imaging; Myocardial infarction; Nanoparticle; Porphysome