Abstract: An assay mixture includes a hydrogel of a shear-thinning ?-hairpin peptide, a plurality of cells, and one or more predetermined compounds being investigated for ability to affect the growth, viability, reproduction characteristics, or activity of the cells. A high throughput screening device includes a plurality of sample wells adapted for high throughput screening, wherein each well contains the assay mixture. A method of using the high throughput screening device includes a) depositing in each of the wells a ?-hairpin hydrogel including the cells; depositing in at least some of the wells one or more of the compounds, either along with the ?-hairpin hydrogel or separately; and c) measuring the growth, viability, reproduction characteristics, or activity of the cells in each of the plurality of wells.