title: Optimal conditions for heart cell cryopreservation for transplantation.
abstract: Cultured myocyte transplantation into an infarcted myocardium has been shown to improve contractile function. Cryopreservation of cultured muscle cells or heart tissue will be important for the technology to be practical. This study, using fetal cardiomyocytes, evaluated the optimal conditions for muscle cell cryopreservation. Study 1: Fetal rat cardiomyocytes were isolated and cultured. The freshly isolated and passage 1, 2, 3 and 4 cells were cryopreserved in a solution containing 70% IMDM, 20% FBS and 10% DMSO and stored in -196 degrees C for 1, 2, 4, 8, 12 and 24 weeks. The cells were thawed and cultured. Cell number and contractility were evaluated at 0, 2, 4, 6, 8 and 10 days of culture. Study 2: Rat myocardium was cryopreserved in sizes of 0.2, 2 and 6 mm3 for 1 week. The tissue was thawed and cells were isolated. Cell growth and contractility were evaluated. (1) Cardiomyocytes grew and contracted after cryopreservation. Storage time did not affect cell survival rate, beating cell numbers and beating rates. Increasing cell passage prior to cryopreservation decreased the percentage of beating cells. (2) Cells isolated from cryopreserved tissue grew in vitro and contracted normally. Cell yield decreased with increased cryopreserved tissue size. Fetal rat cardiomyocytes survived and functioned after in vitro cryopreservation. Viable cells can be isolated from cryopreserved myocardium and cultured. Cryopreservation of small pieces of myocardium is preferred for maximal cell yields.
authors.affiliation: Division of Cardiovascular Surgery, Toronto General Hospital, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yokomuro
authors.forename: Donald A G
authors.initials: DA
authors.lastname: Mickle
authors.forename: Richard D
authors.initials: RD
authors.lastname: Weisel
authors.forename: Ren-Ke
authors.initials: RK
authors.lastname: Li
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002469:Cell Separation; D002470:Cell Survival; D016922:Cellular Senescence; D003080:Cold Temperature; D015925:Cryopreservation / Q000379:methods*; D016332:Fetal Tissue Transplantation / Q000379:methods; D016027:Heart Transplantation / Q000379:methods*; D007545:Isoproterenol / Q000494:pharmacology; D032342:Muscle Cells / Q000166:cytology / Q000502:physiology* / Q000637:transplantation*; D009200:Myocardial Contraction / Q000187:drug effects; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D011433:Propranolol; D007545:Isoproterenol