Simulating a microenvironment of peripheral neural regeneration with polyglycolic/polylactic acid filament-filled amnion tube and pedicled epimysium flap to repair peripheral nerve defect / 中国组织工程研究

ABSTRACT

BACKGROUND:The microenvironment of injured peripheral nerve was one of the most important factors that influence peripheral nerve regeneration. A favorable microenvironment for nerve regeneration would protect damaged neurons and promote axonal regeneration. OBJECTIVE:To simulate the microenvironment of peripheral neural regeneration with an amnion tube filled with polyglycolic polylactic acid(PLGA) filaments and autologous nerve tissue pulps and wrapped with a pedicled epimysium flap,and to study the feasibility to repair sciatic nerve defect. DESIGN,TIME AND SETTING:A randomized controlled study was performed in Experiment Animal Center of Guangdong Medical College from June 2006 to October 2007. MATERIALSThirty SD rats of clean grade and aged 2 months old were randomly divided into experimental group,control group,and standard group,with 10 rats in each group. The right side was operated,and the left side was control. Amnion was obtained from healthy,full-term,and spontaneous delivery fetus whose mothers provided the informed consent to establish amnion matrix membrane. Vicryl thread and amnion matrix membrane were used to make PLGA microfilament bridging graft. METHODS:The 6.0-mm sciatic nerve defect was bridged with different grafts,respectivelythe amnion tube filled with Vicryl filaments and autologous nerve tissue pulps,and wrapped with a pedicled epimysium flap(experimental group) ;the amnion tube filled with autologous nerve tissue pulps(control group) ;autologous nerve(standard group) . MAIN OUTCOME MEASURES:Gross observation,histological examination,wet weight of the anterior tibial muscle,pass-through rate of myelinated nerve fibres and neural electrophysiology were assessed 8 and 12 weeks after the operation. RESULTS:At 12 weeks after operation,amyotrophy was lightly recovered in the experimental and standard groups except control group. Anterior tibial muscle at injured side was ruddy,well-stacked,and flexible in the experimental and standard groups,but the muscle was dark and poor elasticity. At 8 and 12 weeks after operation,there were significant differences in recovery rate of anterior tibial muscle between the three groups;in addition,at 12 weeks after operation,there were also significant differences in numbers of myelinated nerve fibers,cross-section area,vascular numbers of neural graft,vascular cross-section area,and compound muscle action potential amplitude of triceps surae between the three groups(P