Composite PHB-GGF conduit for long nerve gap repair: a long-term evaluation

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Neuroscience

Background:

• Peripheral nerve injuries often result in significant functional deficits.
• Bridging long nerve gaps remains a challenge in nerve repair.
• Poly-3-hydroxybutyrate (PHB) conduits are investigated for nerve regeneration applications.

Purpose of the Study:

• To evaluate the efficacy of poly-3-hydroxybutyrate (PHB) conduits containing glial growth factor (GGF) for bridging long nerve gaps.
• To compare PHB conduits with GGF (PHB-GGF) and alginate matrix (PHB-ALG) against empty PHB conduits (E-PHB).
• To assess the impact of GGF on nerve regeneration, Schwann cell proliferation, axonal growth, and muscle reinnervation.

Main Methods:

• Rabbit common peroneal nerve gaps (2-4 cm) were repaired using PHB-GGF, PHB-ALG, or E-PHB conduits.
• Nerve regeneration was assessed at various time points, including 63 and 120 days postoperatively.
• Histological analysis quantified Schwann cell and axonal regeneration.
• Muscle mass percentage loss was measured as an indicator of reinnervation.

Main Results:

• PHB-GGF conduits significantly promoted nerve regeneration up to 63 days, with sustained long-term effects.
• At 120 days, GGF addition increased Schwann cell and axonal regeneration compared to controls.
• PHB-GGF and E-PHB conduits showed better distal nerve regeneration than PHB-ALG.
• PHB-GGF conduits significantly reduced muscle mass loss compared to control groups.

Conclusions:

• Glial growth factor (GGF)-containing PHB conduits effectively promote sustained axonal regeneration.
• GGF-loaded conduits improve target muscle reinnervation following long nerve gap repair.
• PHB conduits with GGF represent a promising strategy for enhancing peripheral nerve repair outcomes.