title: Effects of large-area irradiated laser phototherapy on peripheral nerve regeneration across a large gap in a biomaterial conduit.
abstract: This paper proposes a novel biodegradable nerve conduit comprising 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) cross-linked gelatin, annexed with β-tricalcium phosphate (TCP) ceramic particles (EDC-Gelatin-TCP, EGT). In this study, the EGT-implant site in rats was irradiated using a large-area 660 nm AlGaInP diode laser (50 mW) to investigate the feasibility of laser stimulation in the regeneration of a 15-mm transected sciatic nerve. The animals were divided into three groups: a sham-irradiated group (EGT/sham); an experimental group undergoing low-level laser (LLL) therapy (EGT/laser); a control group undergoing autologous nerve grafts (autografts). Twelve weeks after implantation, walking track analysis showed a significantly higher sciatic functional index (p < 0.05) and improved toe spreading development in the EGT/laser and autograft groups than in the EGT/sham group. In electrophysiological measurement, both the mean peak amplitude and the area under the compound muscle action potential curves in the EGT/laser and autograft groups showed significantly improved functional recovery than the EGT/sham group (p < 0.05). Compared with the EGT/sham group, the EGT/laser and autograft groups displayed a reduction in muscular atrophy. Histomorphometric assessments revealed that the EGT/laser group had undergone more rapid nerve regeneration than the EGT/sham group. The laser-treated group also presented greater neural tissue area as well as larger axon diameter and thicker myelin sheath than the tube group without the laser treatment, indicating improved nerve regeneration. Thus, these assessments demonstrate that LLL therapy can accelerate the repair of a transected peripheral nerve in rats after being bridged with EGT conduit.
authors.affiliation: Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China.
authors.forename: Chiung-Chyi
authors.initials: CC
authors.lastname: Shen
authors.forename: Yi-Chin
authors.initials: YC
authors.lastname: Yang
authors.forename: Bai-Shuan
authors.initials: BS
authors.lastname: Liu
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000494:pharmacology; D005022:Ethyldimethylaminopropyl Carbodiimide / Q000494:pharmacology; D005780:Gelatin / Q000494:pharmacology; D048091:Guided Tissue Regeneration / Q000379:methods*; D007150:Immunohistochemistry; D028022:Low-Level Light Therapy; D008422:Materials Testing; D009132:Muscles / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D009186:Myelin Sheath / Q000473:pathology; D009416:Nerve Regeneration / Q000187:drug effects*; D009929:Organ Size / Q000187:drug effects; D009993:Osmium Tetroxide / Q000378:metabolism; D019919:Prosthesis Implantation; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000187:drug effects; D012584:Sciatic Nerve / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D013194:Staining and Labeling; D014182:Transplantation, Autologous
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; C485817:beta-tricalcium phosphate; D005780:Gelatin; D009993:Osmium Tetroxide; D005022:Ethyldimethylaminopropyl Carbodiimide