Increased vascularisation enhances axonal regeneration within an acellular nerve conduit

Area of Science:

• Biomedical Engineering
• Neuroscience
• Regenerative Medicine

Background:

• Peripheral nerve repair outcomes remain suboptimal, especially with nerve grafts.
• Autologous nerve grafts have limitations, driving the search for alternatives.
• The impact of vascularization on nerve regeneration requires further definition.

Purpose of the Study:

• To define and quantify the effects of enhanced vascularization on peripheral nerve regeneration.
• To investigate the role of vascular endothelial growth factor (VEGF) in nerve repair.
• To assess functional recovery following VEGF-enhanced nerve regeneration.

Main Methods:

• Utilized silicone chambers with VEGF (500 or 700 ng/ml) in Matrigel to bridge 1 cm rat sciatic nerve defects.
• Harvested chambers from 5 to 180 days post-insertion for analysis.
• Employed immunohistochemical staining and computerized image analysis to quantify neural and vascular elements.

Main Results:

• VEGF significantly increased vascular, Schwann cell, and axonal regeneration up to 30 days.
• At 180 days, VEGF stimulated 78% more myelinated axons compared to controls.
• VEGF enhanced target-organ re-innervation, improving muscle weight (17%) and footpad innervation (51%) dose-dependently.

Conclusions:

• Enhanced vascularization via VEGF significantly promotes peripheral nerve regeneration and functional recovery.
• VEGF offers a promising therapeutic strategy to improve outcomes in peripheral nerve repair.
• A strong positive correlation exists between vascularization and nerve regeneration, supporting VEGF's efficacy.