title: An elastic, biodegradable cardiac patch induces contractile smooth muscle and improves cardiac remodeling and function in subacute myocardial infarction.
abstract: OBJECTIVE
  Our objective in this study was to apply an elastic, biodegradable polyester urethane urea (PEUU) cardiac patch onto subacute infarcts and to examine the resulting cardiac ventricular remodeling and performance.
  
  
  BACKGROUND
  Myocardial infarction induces loss of contractile mass and scar formation resulting in adverse left ventricular (LV) remodeling and subsequent severe dysfunction.
  
  
  METHODS
  Lewis rats underwent proximal left coronary ligation. Two weeks after coronary ligation, a 6-mm diameter microporous PEUU patch was implanted directly on the infarcted LV wall surface (PEUU patch group, n = 14). Sham surgery was performed as an infarction control (n = 12). The LV contractile function, regional myocardial wall compliance, and tissue histology were assessed 8 weeks after patch implantation.
  
  
  RESULTS
  The end-diastolic LV cavity area (EDA) did not change, and the fractional area change (FAC) increased in the PEUU patch group (p < 0.05 vs. week 0), while EDA increased and FAC decreased in the infarction control group (p < 0.05). The PEUU patch was largely resorbed 8 weeks after implantation and the LV wall was thicker than infarction control (p < 0.05 vs. control group). Abundant smooth muscle bundles with mature contractile phenotype were found in the infarcted myocardium of the PEUU group. The myocardial compliance of the PEUU group was distributed between normal myocardium and infarction control (p < 0.001).
  
  
  CONCLUSIONS
  Implantation of a novel biodegradable PEUU patch onto a subacute myocardial infarction promoted contractile phenotype smooth muscle tissue formation and improved cardiac remodeling and contractile function at the chronic stage. Our findings suggest a new therapeutic option against post-infarct cardiac failure.
authors.affiliation: Department of Surgery, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Kazuro L
authors.initials: KL
authors.lastname: Fujimoto
authors.forename: Kimimasa
authors.initials: K
authors.lastname: Tobita
authors.forename: W David
authors.initials: WD
authors.lastname: Merryman
authors.forename: Jianjun
authors.initials: J
authors.lastname: Guan
authors.forename: Nobuo
authors.initials: N
authors.lastname: Momoi
authors.forename: Donna B
authors.initials: DB
authors.lastname: Stolz
authors.forename: Michael S
authors.initials: MS
authors.lastname: Sacks
authors.forename: Bradley B
authors.initials: BB
authors.lastname: Keller
authors.forename: William R
authors.initials: WR
authors.lastname: Wagner
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage*; D002196:Capillaries / Q000187:drug effects; D003187:Compliance / Q000187:drug effects; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000187:drug effects; D006321:Heart / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects*; D009203:Myocardial Infarction / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D009206:Myocardium / Q000473:pathology; D011140:Polyurethanes / Q000008:administration & dosage*; D051381:Rats; D011917:Rats, Inbred Lew; D042461:Vascular Endothelial Growth Factor A / Q000187:drug effects; D020257:Ventricular Remodeling / Q000187:drug effects*
chemical_list: D001672:Biocompatible Materials; D011140:Polyurethanes; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2; C044690:polyetherurethane urea