Abstract 140: Efficacy Evaluation of Transplantation of Three-Dimensional Adipose-derived Stem Cell Sheet With Enhanced Angiogenesis Into Cardiovascular Disease

Abstract

Integration of adipose-derived stem cells (ASCs) and cell sheet engineering technology has received much interest in the regenerative medicine. First of all, sphere formation of ASCs (sph-ASCs) were successfully produced by poly-2-hydroxyethyl methacrylate (poly-HEMA)-coated plates as we previously reported. Sph-ASCs showed increased expression of angiogenic growth factors and cytokine secretion compared to adherent ASCs. Significantly increased expression of HIF-1α and decreased expression of cleaved caspase-3 were detected in sph-ASCs compared to adherent ASCs. Moreover, ASC sheets were formed using thermo-responsive plates and sph-ASCs were seeded to produce ASC sheets covered with sph-ASCs (sph-ASC sheets). After 48 hrs of incubation, the cross-section of sph-ASC sheets revealed mixed and multi-layered of sph-ASCs and ASC sheets. Sph-ASC sheets showed the positive expression of HIF-1α and angiogenic markers such as FGF-2, CD31, PDGFb, and CD144, especially higher in sph-ASC-covered sites. In addition, cytokine arrays of secretome revealed that sph-ASCs and sph-ASC sheets showed augmented angiogenic potential compared to adherent ASCs. Furthermore, four groups of AMI induction only (sham), intramyocardial injection of sph-ASC, ASC sheet transplantation, and sph-ASC sheet transplantation were compared using acute myocardial infarction (AMI) rat models. After 6 weeks of transplantation, echocardiography revealed that significantly improved ejection fraction and fraction shortening in sph-ASC sheet group compared to sham, sph-ASC, and ASC sheet groups. In conclusion, transplantation of sph-ASC sheets showed enhanced neovascularization in AMI animal models. These results indicated that the use of ASC sheets as a novel tissue engineering approach to improve the cardiac and vascular function.