[Favorable effect of chitosan sustained-release FK506 incorporated conduits on axonal regeneration in rat sciatic nerve].
OBJECTIVE
To investigate the efficacy of 3 mm gap bridging repairing neurotmesis with chitosan sustained-release FK506 incorporated conduits.


METHODS
Forty-five adult male SD rats were divided randomly into 3 groups. The rats were received a neurotomy to bilateral sciatic nerve and subsequently reconnected with regeneration chambers. The bridging conduits of group A, B and C were made of silicon tube, chitosan and chitosan sustained-release FK506 incorporated respectively. Conduits absorption and surrounding tissue cicatrization were observed at 6, 8 and 12 weeks after neurotomy. The nerve regeneration and functional recovery were evaluated by electrophysiology, histological changes, morphometric analysis, and weighing of gastrocnemius muscles.


RESULTS
The silicon tubes of group A adhered severely with surrounding tissue. Bridging grafts of group B and C adhered relatively slightly and could be stripped easily from surrounding tissue. The regeneration chambers still existed fully at 6 weeks and began to be degraded at 8 weeks after neurotomy. The bridging grafts of group B and C were disintegrated at 12 weeks and the continuity of sciatic nerve was established without obvious adhesion with surrounding tissue. The statistical evaluation for nerve regeneration demonstrated that rats of group C showed the best results. Although rats of group B and A were found to be the second and the third respectively, there is no significant difference between them.


CONCLUSIONS
Remaining 3 mm gap bridging repairing rat sciatic nerve with chitosan sustained-release FK506 incorporated conduits, which stabilize for more than 2 months before degradation in vivo, can significantly promote nerve regeneration and facilitate function recovery without adverse effects.
Zhang
Wei-guo
WG
Department of Orthopedics, The First Affiliated Hospital of Dalian Medical University, Dalian 116011, China.
Lü
De-cheng
DC
Fu
Chong-yang
CY
Qü
Wei
W
D000818:Animals; D001369:Axons / Q000187:drug effects / Q000502:physiology; D048271:Chitosan / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000737:chemistry; D016503:Drug Delivery Systems; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D009416:Nerve Regeneration / Q000187:drug effects*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000187:drug effects* / Q000502:physiology; D016559:Tacrolimus / Q000008:administration & dosage / Q000494:pharmacology*
D003692:Delayed-Action Preparations; D007166:Immunosuppressive Agents; D048271:Chitosan; D016559:Tacrolimus