Nanofibrous Patches for Spinal Cord Regeneration.

The difficulty in spinal cord regeneration is related to the inhibitory factors for axon growth and the lack of appropriate axon guidance in the lesion region. Here we developed scaffolds with aligned nanofibers for nerve guidance and drug delivery in spinal cord. Blended polymers including Poly (l-lactic acid) (PLLA) and Poly (lactide-co-glycolide) (PLGA) were used to electrospin nanofibrous scaffolds with two-layer structure: aligned nanofibers in the inner layer and random nanofibers in the outer layer. Rolipram, a small molecule that can enhance cAMP activity in neurons and suppress inflammatory responses, was immobilized onto nanofibers. To test the therapeutic effects of nanofibrous scaffolds, the nanofibrous scaffolds loaded with rolipram were used to bridge the hemisection lesion in 8-week old athymic rats. The scaffolds with rolipram increased axon growth through the scaffolds and in the lesion, promoted angiogenesis through the scaffold, and decreased the population of astrocytes and chondroitin sulfate proteoglycans in the lesion. Locomotor scale rating analysis showed that the scaffolds with rolipram significantly improved hindlimb function after 3 weeks. This study demonstrated that nanofibrous scaffolds offered a valuable platform for drug delivery for spinal cord regeneration.