Injectable Nanoreinforced Shape-Memory Hydrogel System for Regenerating Spinal Cord Tissue from Traumatic Injury

Traumatic injury in the central nervous system can lead to loss of functional neurons. Transplantation of neural progenitors is a promising therapeutic strategy. However, infusion of dissociated cells often suffers from low viability, uneven cell distribution, and poor in vivo engraftment that could be reinforced by a better cell delivery system. Here, we develop an injectable composite hydrogel system for use as a minimally invasive treatment of spinal cord injury (SCI) using motor neurons (MNs) derived from embryonic stem cells (ESCs). The composite hydrogel is based on a modified gelatin matrix integrated with shape-memory polymer fibers. The gelatin matrix creates a local microenvironment for cell assembly and also acts as a lubricant during injection through a fine catheter. Notably, shape-memory fiber scaffolds are able to recover to maintain the microstructures even after dramatic deformation from injection operation, providing the necessary support and guidance for motor neuron differentiation. We...