Regeneration of skeletal muscle using in situ tissue engineering on an acellular collagen sponge scaffold in a rabbit model.

Because of the limited ability of skeletal muscle to regenerate, resection of a large amount of muscle mass often results in incomplete recovery due to nonfunctional scar tissue. The aim of this study was to regenerate skeletal muscle using in situ tissue engineering in a rabbit model. In 18 male rabbits, a muscle defect (1.0 x ~1.0 x ~0.5 cm) was created in the vastus lateralis of both legs. A piece of cross-linked atelocollagen sponge was then inserted into the defect in one leg, whereas the defect in the other leg was left untreated. Both defects were finally covered with fascia. Twenty-four weeks after surgery, the defect that had been filled with the cross-linked atelocollagen sponge scaffold showed mild concavity and slight adhesion to the fascia, while the control side showed severe scar formation and shrinkage. Histologically, the regenerating myofibers at the site containing the collagen sponge were greater in number, diameter, and length than those at the control site. These results indicate that cross-linked atelocollagen sponge has the potential to act as a scaffold for muscle tissue regeneration.