The overall goal of this project is to develop a hydrogel that will greatly improve the ability of stem cell-derived therapies to treat spinal cord injury. In order to tailor our hydrogels to mimic the natural environment of nerve cells, we created multiple versions of our hydrogel, each with slightly different material properties. For example, during the past year, we created hydrogels with a broad range of mechanical properties. We found that while all of the hydrogels are injectable and can be used to transplant stem cell-derived neural progenitor cells, the least stiff hydrogels resulted in the most nerve cell outgrowth and were the fastest to degrade in a rat model of spinal cord injury. During the next reporting period, we will synthesize hydrogel versions that engage different cell-surface receptors and that can degrade in response to cell-secreted enzymes.