Cardiac stem cells and uses of same in cardiac repair

Abstract

Method for the isolation, expansion and preservation of cardiac stem cells from human or animal tissue biopsy samples to be employed in cell transplantation and functional repair of the myocardium or other organs. Cells may also be used in gene therapy for treating cardiomyopathies, for treating ischemic heart diseases and for setting in vitro models to study drugs.

What is claimed is: 
     
         1 . A procedure to obtain cardiospheres able to repair damaged myocardiac tissue, comprising:
 a. take a biopsy sample of cardiac tissue and keep it in an appropriate culture medium;   b. treat the specimen under appropriate conditions with mild mechanical, chemical or enzymatic techniques to obtain fragments of the sample size large enough to allow diffusion of nutrients present in the medium;   c. fix the tissue fragments to appropriate solid supports and maintain them in a medium containing serum and/or adequate growth factors;   d. allow the cells to grow, changing the medium partially or completely, until multicellular structures form that are either weekly adherent or do not adhere to the support;   e. separate these multicellular structures from the rest of the medium;   f. treat the structures by mild dissociation until most of the small phase bright spherical cells detach but maintain their morphologic and functional characteristics;   g. plate the cells on culture substrates treated with polylysine or other agents promoting the adhesion of the culture to the support in a medium containing at least the minimal essential constituents for the growth of mammalian cells;   h. possibly repeat steps d) to g) at least once;   i. select the cells that aggregate in phase bright spheroid formations (cardiospheres);   j. selectively promote the formation of new Cardiospheres by mild dissociation and new formation;   k. selectively cryopreserved the Cardiospheres for use after thawing.