Human mesenchymal stromal cells are cells that, when primed with cytokines, secrete immunomodulatory factors that may be used to treat a variety of immune diseases. Traditionally, these cells are seeded atop two-dimensional substrates for priming, but cells in vivo reside in a three dimensional matrix. As such, encapsulation of cells within three-dimensional polymeric hydrogels could increase their productivity. When looking to further maximize the production of these factors, other variables such as stiffness, degradability, and adhesiveness of the gel, are all being observed in their effects. My study will be using a non degrading non adhesive photogel to control for these variables. I will be comparing the cell viability in the new versus old batch of polymer, at different weight percentages, causing varying stiffnesses. The newer batch seems to be less viable, and this study will look to confirm if this is true, and what the difference between batch production may be. Photogel stiffness will also be analyzed in its effects on cell viability and factor production.