Adult cardiac myocytes survive and remain excitable during long-term culture on synthetic supports

Objective: Cardiomyocytes can be transplanted successfully into skeletal an d cardiac muscle. Our goal was to determine the feasibility of grafting car diomyocytes onto various synthetic supports to create an excitable and viab le tissue for implantation. Methods: Adult rat cardiomyocytes were cultured over an 8-week period onto different substitutes, including human glutaraldehyde-treated peri cardium (n = 3), equine glutaraldehyde-treated pericardium (n = 3), polytetrafluoro ethylene (n = 8), Dacron polyester (n = 16), and Vicryl poly-glactin (n = 8 ). Results: Only the cells seeded on the Dacron survived, with the synthetic f ibers colonized at 8 weeks. On the other supports, the number of myocytes p rogressively decreased from the first week, with their density (number of c ells per square millimeter) being, after 20 days, 17 +/- 2 on the polytetra fluoroethylene and 5 +/- 1 on the human or equine pericardium compared with 45 +/- 3 on the Dacron. After 8 weeks of culture on Dacron, the sarcomeric protein (sarcomeric a-actinin) was detected in all cells. In addition, the staining was regularly arranged and well aligned in a striated pattern. Sp ontaneous beating activity was obtained. Moreover, electrical stimulation o f the cell preparation resulted in the generation of calcium transients, th e frequency of which followed the frequency of the electrical stimulation. Conclusions: These results suggest that adult cardiac myocytes remain viabl e and excitable during long-term culture on a S-dimensional Dacron support, which might constitute a new synthetic cardiac tissue.