Comparison of Cellular Architecture, Axonal Growth, and Blood Vessel Formation Through Cell-Loaded Polymer Scaffolds in the Transected Rat Spinal Cord

This study investigates the use of polymer scaffolds loaded with different cell types to promote regeneration after spinal cord injury in rats. The scaffolds were implanted after a complete spinal cord transection, and the effects of Schwann cells and mesenchymal stem cells (MSCs) on tissue regeneration, axonal growth, and blood vessel formation were compared. The researchers examined how each scaffold type influenced the architecture of the regenerated tissue, focusing on astrocytosis (scarring), axon regeneration, and blood vessel growth. They used immunohistochemistry and stereology to analyze the cellular composition and structure within the scaffolds. The study found that Schwann cells augmented axon regeneration, while MSCs did not support axon growth. Additionally, Schwann cells led to the formation of high numbers of small, densely packed blood vessels, while MSCs resulted in fewer, larger vessels. These differences in blood vessel morphology correlated with axonal regeneration, suggesting the importance of blood flow rate and vessel density.

• 1
  Axon regeneration was significantly augmented by Schwann cell implantation, while eGFP-MSCs did not support axon growth in the transected spinal cord.
• 2
  Schwann cell scaffolds had high numbers of small, densely packed blood vessels, while eGFP-MSC scaffolds contained fewer, larger vessels.
• 3
  There was a positive linear correlation between axon counts and vessel length density, surface density, and volume fraction; increased axon number also correlated with decreasing vessel diameter.