SCIATIC-NERVE REGENERATION NAVIGATED BY LAMININ-FIBRONECTIN DOUBLE COATED BIODEGRADABLE COLLAGEN GRAFTS IN RATS

Biodegradable type I collagen tube grafts filled longitudinally with l aminin and fibronectin double coated collagen fiber bundles (L-F graft s) were implanted to promote sciatic nerve regeneration in rats. Graft s filled with uncoated collagen fibers were used as control. A 1 cm de fect on the right sciatic nerve was filled with a graft in the manner of bridging. Thirty days after implantation, several newly developed n erve fasciculi were found at the middle portion of the L-F grafts in c ontrast to no developed nerves in the controls. After 60 days, the mid dle and distal portions of both grafts included well-developed nerve t issues with prominent myelinated and unmyelinated nerve fibers surroun ded by perineural cells, but the control distal portion showed fewer n erve fibers. All artificial collagen elements were completely degraded and absorbed at 30 days, and new nerve tissues surrounded by an epine urium successfully connected the proximal stump to the distal stump of the initially separated nerve. Descending and ascending action potent ials were evoked in all grafts at 60 days. These results indicated tha t laminin and fibronectin may promote the growth of axons in biodegrad able collagen grafts, which guided nerve regeneration well and allowed the formation of epineurium.