Background-There is compelling evidence showing that cellular cardiomyoplasty can improve cardiac function.Considering the potential benefit of using noncultured muscle cells (little time, lower cost, reduced risk of contamination), we investigated the feasibility of grafting cells obtained directly after enzymatic dissociation of skeletal muscle biopsies into ovine myocardium. We hypothesized that those noncultured muscle cells would engraft massively. Methods and Results-Autologous, intramyocardial skeletal muscle cell implantation was performed in 8 sheep. A skeletal muscle biopsy sample (Ϸ10 g) was explanted from each animal. The sheep were left to recover for Ϸ3 hours and reanesthetized when the cells were ready for implantation. A left fifth intercostal thoracotomy was performed, and 10 epicardial injections of the muscle preparation (between 10 and 20 million cells) were carried out. All sheep were euthanized 3 weeks after myocardial implantation. Immunohistochemistry was performed with monoclonal antibodies to a fast skeletal isoform of myosin heavy chain. Skeletal myosin heavy-chain expression was detected in all slides at 3 weeks after implantation in 8 of 8 animals, confirming engraftment of skeletal muscle cells. Massive areas of engraftment (from 2 to 9 mm in diameter) or discrete loci were noted within the myocardial wall. Conclusions-Our results indicate that noncultured skeletal muscle cells can successfully and massively engraft in ovine myocardium. Thus, avoiding the cell culture expansion phase is feasible and could become a promising option for cellular cardiomyoplasty. Key Words: heart Ⅲ cells Ⅲ transplantation Ⅲ infarction Ⅲ muscles T he concept of myogenic cell transplantation into the myocardium, known as cellular cardiomyoplasty (CCM), is based on the contribution of exogenous cells to replace lost or altered cardiomyocytes to restore functional performance of the heart. 1 There is a large body of evidence showing that CCM can improve cardiac function in ischemic heart disease, 2-14 as well as dilated cardiomyopathy, [15][16][17] in numerous animal models.Most research teams have addressed autologous CCM in a 3-phase process: biopsy, ex vivo cell culture/expansion, and surgical or catheter-based cell delivery. Considering the potential benefit of using noncultured muscle cells (little time, lower cost, reduced risk of contamination), we investigated the feasibility of grafting noncultured cells into ovine myocardium.
Methods
Animal ModelThe study was approved by the institutional ethics committee for animal research, and all animals received humane care in compliance with the Guide for the Care and Use of Laboratory Animals prepared by the Institute of Laboratory Animal Resources, National Research Council, and published by the National Academy Press, revised 1996. Autologous, intramyocardial skeletal muscle cell extract implantation was carried out in eight 1-year-old Ile de France sheep weighing 63 to 67 kg (Lycée Agricole et Vinicole, Crézancy, France). Three other animals were inject...