| Engineered myocardium may help the heart regain function following a myocardial infarction, but the success of the engineered muscle relies on its ability to contract. To maintain consistent and synchronous beating to provide useful mechanical work, the engineered tissue must be able to deform the growth substrata. Elastomeric materials promote contraction while rigid materials can inhibit beating. Two scaffold preparation methods, injection molding and solvent casting/salt leaching, were used to create scaffolds. Injection molded scaffolds were made of poly(D,L-lactic acid) (PLA) and seeded with P19 embryonal carcinoma cells. While the cells adhered and proliferated, the scaffolds lacked the porosity needed for a tissue engineering scaffold. Additionally, PLA is a rigid material and not suitable for cardiac tissue engineering. However, injection molding may be a promising scaffold preparation technique if a thermoplastic elastomer is used and if the molding procedure is somewhat modified. A solvent casting/salt leaching method was used to produce highly porous scaffolds out of four materials of differing elasticity: poly(D,L-lactic-co-glycolic acid) (PLGA) (85:15), poly(D,L-lactide-co-caprolactone) (PLCL) (50:50), thermoplastic polyurethane (PU), and poly(glycerol sebacate) (PGS). P19 derived cardiomyocytes were seeded onto the scaffolds. The cells were tested by immunocytochemistry to investigate the levels of different cardiac markers. The contractile function of the cells was determined by monitoring voltage of the pulsations. Scanning electron microscopy was performed to observe the morphology of the cells in contact with the scaffolds. PU may be a suitable choice because it supported cell proliferation and cell contraction. However, PGS is the most suitable substrate for a cardiac tissue engineering scaffold, given it has an elastic modulus comparable to myocardium. Injection molding may be a promising technique for scaffold fabrication, but the procedure and material must be modified. Solvent casting/salt leaching proved to be an appropriate method for creating highly porous scaffolds. |
