Biopolymers and biodegradable smart implants for tissue regeneration after spinal cord injury.

PURPOSE OF REVIEW: This article reviews recent experimental advances in the development of biosynthetic implants for repair of spinal cord injury. RECENT
FINDINGS: Various important advances in the development of biosynthetic conduits for spinal cord repair have recently been reported. It was found that implantation of freeze dried alginate sponge into completely transected spinal cord supports axonal regeneration across the lesion site. A poly(lactic-co-glycolic acid) scaffold seeded with neural stem cells has been developed that promotes axonal regeneration across the gap. It was found that polyethylene glycol can reseal damaged spinal cord axons and restore impulse conduction. Findings have been reported that poly-beta-hydroxybutyrate conduits in combination with alginate and fibronectin provide neuroprotection for axotomized descending neurones. It has been reported that conduits made of fibronectin mats or fibrin in combination with neurotrophic growth factors promote axonal growth into the grafts. Finally, magnetic resonance imaging after experimental spinal cord injury has been used to monitor regeneration in biosynthetic conduits in vivo over time.
SUMMARY: Biosynthetic conduits carrying extracellular matrix molecules and different cell lines, and supplemented with neurotrophic growth factors have yielded encouraging results in the treatment of experimental spinal cord injury. These findings provide a basis for further development of techniques aimed at spinal cord repair in humans.