Autologous engineered cartilage rods for penile reconstruction

Conditions such as inadequate and ambiguous genitalia that are caused by rudimentary penis, severe hypospadias or traumatic injury require surgical intervention. Although silicone penile prostheses are an accepted treatment modality, biocompatibility issues may be a problem in select cases. We previously demonstrated that rods composed of cartilage could be created using chondrocytes seeded on biodegradable polymer scaffolds. We showed that the cartilage rods engineered ex situ were readily elastic and withstood high degrees of pressure. We investigated the feasibility of applying the engineered cartilage rods in situ in an animal model.

Autologous chondrocytes harvested from rabbit ears were grown and expanded in culture. Cells were seeded onto biodegradable poly-L-lactic acid coated polyglycolic acid polymer rods at a concentration of 50 x 10(6) chondrocytes per cm3. A total of 18 chondrocyte polymer scaffolds were implanted into the corporal spaces in 10 rabbits. As controls, 1 corpus in each of 2 rabbits was not implanted. The animals were sacrificed 1, 2, 3 or 6 months after implantation. Histological analysis was performed using hematoxylin and eosin, aldehyde fuschin-alcian blue and toluidine blue staining.

All animals tolerated the implants for the duration of the study without any complications. Gross examination after retrieval at 1 month showed well formed, milky white cartilage structures within the corpora. All polymers were fully degraded by 2 months. There was no evidence of erosion or infection at any of the implant sites. Histological analysis using alcian blue and toluidine blue staining revealed mature and well formed chondrocytes in the retrieved implants.

Autologous chondrocytes seeded on preformed biodegradable polymer structures form cartilage structures within the rabbit corpus cavernosum. This technology appears to be useful for creating autologous penile prostheses.