A method to improve cellular content for corporal tissue engineering.

We have previously shown that penile corporal structures engineered using autologous cells are able to achieve erection, penetration, and ejaculation. However, fully functional corpora could not be engineered because of the limited cellular content present within the corporal tissue construct. In this study, we investigated whether a dynamic seeding approach would improve cellularity within the corporal tissue construct and thereby restore normal erectile function. Corporal cells were either statically or dynamically seeded on acellular corporal tissue matrices and maintained in a bioreactor system. After 48 h, the cell-matrix complexes were implanted subcutaneously in athymic mice and analyzed for cell attachment, survival, and distribution using histological and molecular techniques. Native tissues and matrices without cells served as controls. The seeded cells attached and proliferated within the sinusoidal walls of the matrices. After completing the seeding, the DNA and cellular content of the dynamically seeded matrices reached 71% of normal corpora, whereas the statically seeded matrices reached 39% of normal corpora. These findings were confirmed histologically, biochemically, and using scanning electron microscopy. This study demonstrates that dynamic cell attachment, using a bioreactor system, leads to the formation of morphologically and biochemically improved corporal tissue, which may be useful for penile reconstruction.