Granular Hydrogels for Harnessing the Immune Response.

This review aims to understand the current progress in immune-instructive granular hydrogels and identify the key features used as immunomodulatory strategies. We systematically reviewed published work and collected relevant information about granular hydrogels used throughout these studies. We cataloged the base polymer, microgel generation technique, polymer crosslinking chemistry, particle size and shape, annealing strategy, granular hydrogel stiffness, pore size and void space, degradability, biomolecule presentation, and drug release for each paper. We identified several granular hydrogel parameters used for immune modulation: porosity, architecture, bioactivity, drug release, cell delivery, and modularity. We found in our review that porosity is the most significant factor influencing the innate immune response to granular hydrogels, while incorporated bioactivity is more significant in influencing adaptive immune responses. Here, we present our findings and summarized results from each section and make suggestions for future studies to better understand the benefits of using immune-instructive granular hydrogels. This article is protected by copyright. All rights reserved.