Robust CNS regeneration after complete spinal cord transection using aligned poly-L-lactic acid microfibers

Area of Science:

• Neuroscience
• Regenerative Medicine
• Biomaterials Science

Background:

• Axonal regeneration is limited following spinal cord injury without intervention.
• Developing effective strategies for central nervous system (CNS) repair is crucial.

Purpose of the Study:

• To investigate the efficacy of aligned microfiber-based grafts in promoting CNS tissue regeneration.
• To compare the regenerative potential of aligned, random, and film microfiber conduits in a rat spinal cord injury model.

Main Methods:

• Grafting of aligned, random, and film poly-L-lactic acid microfiber conduits into a 3 mm thoracic spinal cord gap in rats.
• Assessment of tissue infiltration, gap closure, axonal regeneration, and astrocyte alignment over 4 weeks.
• Retrograde tracing to identify the origin of regenerating axons.

Main Results:

• Aligned and random microfibers facilitated host tissue infiltration and gap closure by endogenous cells.
• Aligned microfiber grafts supported significantly greater long-distance axonal regeneration (2055 ± 150 µm) compared to random (1162 ± 87 µm) and film (413 ± 199 µm) conduits.
• Regenerating axons originated from propriospinal and supraspinal neurons.

Conclusions:

• Aligned microfiber-based grafts are effective in fostering robust regeneration of vascularized CNS tissue.
• The microtopography of aligned fibers plays a critical role in guiding long-distance axonal regeneration.
• These findings have significant implications for regeneration biology and the development of therapies for spinal cord injury.