Regeneration of the rat sciatic nerve in the silicone chamber model.

The silicone nerve regeneration chamber is a useful model to investigate the cellular and molecular events underlying successful regeneration in the peripheral nervous system. In this model a transected rat sciatic nerve with a 10-mm interstump gap, is repaired with a silicone chamber. The spatial-temporal sequence of regeneration in the silicone chamber has been examined in detail. The chamber rapidly becomes filled with fluid which contains neurotrophic activity for neurons in vitro. The second event to occur is the formation of a fibrin matrix connecting the two nerve stumps. This matrix is then invaded by cellular elements in the following order: perineurial-like cells, vasculature, Schwann cells, and axons. The silicone chamber model also allows manipulation of the regeneration process. Prefilling the chamber at the time of implantation with phosphate-buffered saline or dialyzed plasma stimulates nerve regeneration. Multiple injections into the chamber of a mixture containing laminin, testosterone, and ganglioside GM1 increase the size and the vascularization of the regenerate. Specially designed chambers divided into two compartments by a longitudinally inserted nitrocellulose strip have been used to examine the effects of substrate-bound trophic factors on nerve regeneration. Fibroblast growth factor containing chambers have an improved regeneration and vascularization as compared to controls.