Biomaterial Approaches to Enhancing Neurorestoration after Spinal Cord Injury: Strategies for Overcoming Inherent Biological Obstacles

Spinal cord injuries (SCI) often result in permanent loss of motor function due to the failure of neuronal connections to repair themselves. Post-injury, the spinal cord environment becomes inhibitory to neural regeneration. This review explores the use of biomaterials in therapeutic treatments to overcome this inhibitory environment and enhance functional recovery. Current SCI treatments focus on enhancing neuronal survival, regenerating damaged axons, and promoting neuroplasticity. However, no single therapy has been found to reverse SCI damage due to the spinal cord's complexity. Researchers need to consider the biological implications of each therapy in conjunction with the inherent response to SCI. The review discusses the challenges posed by the post-injury response of the spinal cord, current strategies for functional repair, and the potential use of biomaterials in aiding the recovery process. It emphasizes the importance of understanding the inherent biological response of the central nervous system (CNS) to both injury and subsequent therapeutic interventions.

• 1
  The postinjury environment of the spinal cord is hostile to regenerative processes due to molecular changes, inflammation, and the creation of a hypoxic environment. This leads to reactive astrogliosis, forming a chemophysical barrier that inhibits regenerative activity.
• 2
  Chondroitin sulfate proteoglycans (CSPGs) are upregulated following injury, inhibiting regeneration. They prevent oligodendrocyte differentiation and activate inhibitory signaling cascades in neurons, leading to growth cone collapse and abortion of the regenerative process.
• 3
  Myelin debris from damaged oligodendrocytes contains proteins like Nogo-A, which inhibit axonal regeneration. These proteins interact with surface receptors and provide repulsive axonal guidance cues, collapsing or retracting the axonal growth cone.