Objective: A key challenge to applying cell transplantation to treat severely damaged myocardium is in delivering large numbers of cells with minimum cell loss. We developed a new implantation method using skeletal myoblast (SMB) sheets, wrapped with an omentum flap as a blood supply to deliver huge numbers of SMBs to the damaged heart. We examined whether this method could be used to deliver a large amount of cells to deteriorated porcine myocardium.
Methods: Cell sheets were obtained by culturing mini-pig autologous SMB cells on temperature-responsive culture dishes. Myocardial infarction was induced by placing an ameroid constrictor around the left anterior descending artery. The mini-pigs were divided into 4 treatment groups (n = 6 in each): cell sheets with omentum, cell sheets only, omentum only, and sham operation. Each animal implant consisted of 30 cell sheets (1.5 × 10(7) cells per sheet). Six 5-layer constructs were each placed on a different area, immediately adjacent to but not overlapping one another, to cover the infarct and border regions.
Results: The new regenerative cell delivery system using SMB sheets covered and wrapped with omentum resulted in (1) a significantly reduced infarct size causing, at least in part, a thin scar with thick well-vascularized cardiac tissue; (2) increased angiogenesis, as determined by a significantly higher vascular density; and (3) improved cardiac function, as determined by echocardiography, compared with the conventional method (SMB sheet implantation).
Conclusions: This cell delivery system shows potential for repairing the severely failed heart.
Copyright © 2011. Published by Mosby, Inc.