title: The effects of gradients of nerve growth factor immobilized PCLA scaffolds on neurite outgrowth in vitro and peripheral nerve regeneration in rats.
abstract: Introducing concentration gradients of nerve growth factor (NGF) into conduits for repairing of peripheral nerve injury is crucial for nerve regeneration and guidance. Herein, combining differential adsorption of NGF/silk fibroin (SF) coating, the gradient of NGF-immobilized membranes (G-Ms) and nanofibrous nerve conduits (G-nNCs) were successfully fabricated. The efficacy of NGF gradients was confirmed by a quantitative comparison of dorsal root ganglia (DRG) neurite outgrowth on the G-Ms or uniform NGF-immobilized membranes (U-Ms). Significantly, the neurite turning ratio was 0.48 ± 0.11 for G-M group, but it was close to zero for U-M group. The neurite length of DRGs in the middle of the G-Ms was significantly longer than that of U-M group, even though the average NGF concentration was approximated. Furthermore, 12 weeks after implantation in rats with a 14 mm gap of sciatic nerve injury, G-nNCs achieved satisfying outcomes of nerve regeneration associated with morphological and functional improvements, which was superior to that of the uniform NGF-immobilized nNCs (U-nNCs). Sciatic function index (SFI), compound muscle action potentials (CMAPs), total number of myelinated nerve fibers, thickness of myelin sheath were similar for the G-nNCs and autografts, with the G-nNCs having a higher density of axons than the autografts. Our results demonstrated the significant role of introducing NGF gradients into scaffolds in promoting nerve regeneration.
authors.affiliation: DSAPM Lab, PCFM Lab, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Tang
authors.forename: Jixiang
authors.initials: J
authors.lastname: Zhu
authors.forename: Yangbin
authors.initials: Y
authors.lastname: Xu
authors.forename: Andy Peng
authors.initials: AP
authors.lastname: Xiang
authors.forename: Mei Hua
authors.initials: MH
authors.lastname: Jiang
authors.forename: Daping
authors.initials: D
authors.lastname: Quan
mesh_terms: D000818:Animals; D001369:Axons / Q000187:drug effects / Q000378:metabolism; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology*; D048091:Guided Tissue Regeneration; D008297:Male; D008567:Membranes, Artificial; D020932:Nerve Growth Factor / Q000008:administration & dosage* / Q000627:therapeutic use; D009416:Nerve Regeneration / Q000187:drug effects*; D016501:Neurites / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000187:drug effects / Q000293:injuries / Q000502:physiology*; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D008567:Membranes, Artificial; D020932:Nerve Growth Factor