A silicone tube (S-tube) was packed with CPLA (copolymer of poly-L-lactide)
fibers (S-tube+CPLA) or collagen fibers (S-tube+fiber). Two types of tube
were prepared from a collagen sheet (Col-tube) and a bioabsorbable atelocol
lagen membrane for guided tissue regeneration (GTR-tube). They were packed
with collagen fibers or films (Coltube+fiber, GTR-tube+fiber and GTR-tube+f
ilm). Bridge grafting (15 mm in length) was performed with these tubes in a
rat sciatic nerve model. Specimens were harvested after 8 weeks. Minifasci
cles were formed in the open space between the CPLA fibers in the S-tube+CP
LA group. Regenerated axons were also formed in the degenerated colla gen f
ibers in the S-tube+Col group. Immunocytochemistry evaluation revealed that
Schwann cells invaded the space in the absorbing collagen fibers. Histolog
ic analysis of the regenerated axons in the groups with Col-tubes or GTR-tu
bes revealed that both the Col-tube and the GTR-tube packed with collagen f
ibers were effective in providing a scaffold for regenerating nerve tissue.