title: Placement of an elastic biodegradable cardiac patch on a subacute infarcted heart leads to cellularization with early developmental cardiomyocyte characteristics.
abstract: BACKGROUND
  Placement of an elastic biodegradable patch onto a subacute myocardial infarct (MI) provides temporary elastic support that may act to effectively alter adverse left ventricular (LV) remodeling processes.
  
  
  METHODS
  Two weeks after permanent left coronary ligation in Lewis rats, the infarcted anterior wall was covered with polyester urethane urea (MI + PEUU; n = 15) or expanded polytetrafluoroethylene (MI + ePTFE; n = 15) patches, or had no implantation (MI + sham; n = 12). Eight weeks after surgery, cardiac function and histology were assessed.
  
  
  RESULTS
  The ventricular wall in the MI + ePTFE and MI + sham groups was composed of fibrous tissue, whereas PEUU implantation induced α-smooth muscle actin-positive muscle bundles coexpressing sarcomeric α-actinin and cardiac-specific troponin-T. This pattern of colocalization was also found in developing embryonic myocardium. Cardiac transcription factors Nkx-2.5 and GATA-4 were strongly expressed in the muscle bundles. In the MI + sham group, end-diastolic LV cavity area (EDA) increased and the percentage of fractional area change (%FAC) decreased. For ePTFE patched animals, both EDA and %FAC decreased. In contrast, with MI + PEUU patching, %FAC increased and EDA was maintained. With dobutamine-stress echocardiography, MI + PEUU patched LVs possessed contractile reserve significantly larger than the MI + sham group.
  
  
  CONCLUSIONS
  MI + PEUU patch implantation onto subacute infarcted myocardium induced muscle cellularization with characteristics of early developmental cardiomyocytes as well as providing a functional reserve.
authors: Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15219, USA.
authors: Kazuro L
authors: KL
authors: Fujimoto
authors: Kimimasa
authors: K
authors: Tobita
authors: Jianjun
authors: J
authors: Guan
authors: Ryotaro
authors: R
authors: Hashizume
authors: Keisuke
authors: K
authors: Takanari
authors: Christina M
authors: CM
authors: Alfieri
authors: Katherine E
authors: KE
authors: Yutzey
authors: William R
authors: WR
authors: Wagner
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001672:Biocompatible Materials / Q000008:administration & dosage*; D018031:Connexin 43 / Q000378:metabolism; D004452:Echocardiography; D004548:Elasticity; D005260:Female; D005333:Fetus; D005355:Fibrosis; D050991:GATA4 Transcription Factor / Q000235:genetics / Q000378:metabolism; D006321:Heart / Q000196:embryology; D006352:Heart Ventricles / Q000473:pathology; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009203:Myocardial Infarction / Q000473:pathology* / Q000628:therapy*; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology*; D011138:Polytetrafluoroethylene; D011140:Polyurethanes; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D012038:Regeneration; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D020107:Troponin T / Q000378:metabolism; D020257:Ventricular Remodeling
chemical_list: D000199:Actins; D001672:Biocompatible Materials; D018031:Connexin 43; D050991:GATA4 Transcription Factor; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; D011138:Polytetrafluoroethylene; D011140:Polyurethanes; D012333:RNA, Messenger; D014157:Transcription Factors; D020107:Troponin T; C484469:Nkx2-5 protein, mouse; C115016:polyetherurethane; C498862:Acta2 protein, rat