Summary Biomaterial scaffolds represent a promising approach for material-based tissue regeneration. We previously developed microporous annealed particle (MAP) hydrogels - a flowable, microparticle-based hydrogel in which neighboring hydrogel particles are linked in situ to form a porous scaffold that accelerates wound healing. Recently, we found that a relatively simple modification to the crosslinker peptide from L-enantiomer to D- enantiomer resulted in substantial skin regeneration and that this regeneration only occurs when the adaptive immune system is intact. Further investigation revealed that although D-chiral peptides were poor activators of macrophage innate immune signaling, D-chiral peptides within MAP (D-MAP) elicited significant antigen-specific immunity. In this proposal, we will further investigate the ability of our D-MAP material to activate the adaptive immune system and lead to skin tissue regeneration. Aim 1 will focus on further understanding any role of the innate immune system and the ability of MAP scaffold microstructure to dictate macrophage phenotype. Aim 2 will focus on testing our hypothesis that the adaptive immune system is activated by our material and leads to regenerative wound healing. Aim 3 will investigate other biomaterial approaches to present D-peptides and further control immune system activation.