Many disorders result in tissue degeneration, including Parkinson’s disease, heart attacks, and liver failure. One promising approach to treat these disorders is cell replacement therapy, which would implant new cells or tissues to replace those damaged by disease. Cell replacement therapy relies on stem cells, which are able to differentiate into a wide number of mature cell types. However, cell replacement therapies require large numbers of cells to clinically develop and commercialize, and the current stem cell culture methods are problematic in multiple ways, including low cell yields in 2D and poorly defined culture components. By culturing stem cells three-dimensionally, instead of two-dimensionally, far larger numbers of cells can be generated. Current three-dimensional culturing systems, however, often exert harmful shear stresses and pressures on the cells, have harsh cell recovery steps, do thus not generate large cell yields. UC Berkeley researchers have developed new materials intended for use in fully chemically defined processes for large-scale growth and differentiation of stem cells. These materials prevent harsh cell recovery steps, and can be used in a defined, highly tunable, and three-dimensional cell culture system.