Sara Alicia González Porto1, Nieves Domenech2,3, Francisco J Blanco4, Alberto Centeno Cortés5, Casto Rivadulla Fernández6, Ángel Álvarez Jorge7, Jacinto Sánchez Ibáñez8, Esther Rendal Vázquez8. 1. Servicio de Cirugía Plástica, Hospital POVISA, Vigo, Spain. 2. Biobanco A Coruña, Instituto de Investigación Biomédica de A Coruña (INIBIC), Servicio Galego de Saúde (SERGAS), A Coruña, Spain. 3. Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain. 4. Grupo de Investigación de Proteómica-PBR2-ProteoRed/ISCIII-Servicio de Reumatología, Instituto de Investigación Biomédica de A Coruña (INIBIC), Complexo Hospitalario Universitario de A Coruña (CHUAC), Servicio Galego de Saúde (SERGAS), Universidade da Coruña (UDC), A Coruña, Spain. 5. Centro Tecnológico de Formación XXIAC, Instituto de Investigacións Biomédicas de A Coruña (INIBIC), Servicio Galego de Saúde (SERGAS), A Coruña, Spain. 6. Grupo de Neurociencia e Control Motor, NEUROcom, Facultade de Ciencias da Saúde, Departamento de Ciencias Biomédicas, Fisioterapia e Medicina, Instituto de Investigacións Biomédicas de A Coruña (INIBIC), A Coruña, Spain. 7. Servicio de Cirugía Plástica, Complexo Hospitalario Universitario de A Coruña (CHUAC), Servicio Galego de Saúde (SERGAS), A Coruña, Spain. 8. Unidad de Criobiología, Banco de Tejidos, Complexo Hospitalario Universitario de A Coruña (CHUAC), Servicio Galego de Saúde (SERGAS), A Coruña, Spain.
Abstract
BACKGROUND: Insulin-like growth factor 1 (IGF-1) was found to stimulate Schwann cell mitosis. Exogenous IGF-1 may improve nerve regeneration after cryopreservation. OBJECTIVE: To evaulate the effect of intraneural administration of IGF-1 in cryopreserved nerve isografts. METHODS: Eighteen millimeter grafts were used for bridging an 18-mm defect in the rat sciatic nerve. A total of 57 rats were randomly divided into three groups: (1) autograft (Group 1); (2) cryopreserved isograft (Group 2); (3) cryopreserved isograft with intraneural IGF-1 administration (Group 3). 12 weeks after surgery, functional recovery (Sciatic functional index [SFI], Swing speed [SS], nerve conduction velocity [NCV], amplitude of compound motor action potentials [CMAP], and gastrocnemius muscle index [GMI]) and nerve regeneration (myelin sheath area, total fiber counts, fiber density, and fiber width) were all evaluated. RESULTS: The intraneural injection of IGF-1 significantly improved SFI and SS at weeks 10 and 12. There were no statistical differences between Groups 1 and 3 in any of the SFI or SS evaluations. CMAP and NCV in Group 1 were significantly higher than in Groups 2 and 3, and Group 3 had significantly higher CMAP and NCV compared to Group 2. No significant differences were found in fiber width. The number of nerve fibers, percentage of myelinated fibers, fiber density, and GMI was significantly higher in Group 1 compared to Group 2, but no significant differences were found between Groups 1 and 3. CONCLUSION: The results show that intraneural injection of IGF-1 in an 18 mm cryopreserved isograft improve axonal regeneration and functional recovery.
BACKGROUND:Insulin-like growth factor 1 (IGF-1) was found to stimulate Schwann cell mitosis. Exogenous IGF-1 may improve nerve regeneration after cryopreservation. OBJECTIVE: To evaulate the effect of intraneural administration of IGF-1 in cryopreserved nerve isografts. METHODS: Eighteen millimeter grafts were used for bridging an 18-mm defect in the rat sciatic nerve. A total of 57 rats were randomly divided into three groups: (1) autograft (Group 1); (2) cryopreserved isograft (Group 2); (3) cryopreserved isograft with intraneural IGF-1 administration (Group 3). 12 weeks after surgery, functional recovery (Sciatic functional index [SFI], Swing speed [SS], nerve conduction velocity [NCV], amplitude of compound motor action potentials [CMAP], and gastrocnemius muscle index [GMI]) and nerve regeneration (myelin sheath area, total fiber counts, fiber density, and fiber width) were all evaluated. RESULTS: The intraneural injection of IGF-1 significantly improved SFI and SS at weeks 10 and 12. There were no statistical differences between Groups 1 and 3 in any of the SFI or SS evaluations. CMAP and NCV in Group 1 were significantly higher than in Groups 2 and 3, and Group 3 had significantly higher CMAP and NCV compared to Group 2. No significant differences were found in fiber width. The number of nerve fibers, percentage of myelinated fibers, fiber density, and GMI was significantly higher in Group 1 compared to Group 2, but no significant differences were found between Groups 1 and 3. CONCLUSION: The results show that intraneural injection of IGF-1 in an 18 mm cryopreserved isograft improve axonal regeneration and functional recovery.