Macrophage polarization guided by immunomodulatory hydrogels

Hydrogels are among the most common biomaterials used for regenerative medicine applications. Amongst the important properties needed by hydrogels for their effective use in regenerative medicine, immunomodulation has sparked interest in researchers. This refers to the ability of the material to control the immune system upon implantation and drive it toward a favorable response, thus avoiding chronic inflammation and promoting functional tissue regeneration. In this context, modulating macrophage polarization proves to be a powerful immunomodulatory tool, by inducing the switch of macrophage phenotype from the classic inflammatory M1 phenotype or the antiinflammatory M2 phenotype. This chapter provides an overview of the current immunomodulatory hydrogels from natural and synthetic origins. The focus is on hydrogels able to modulate macrophage polarization towards the antiinflammatory M2 phenotype, either by loading them with immunomodulatory therapeutics or by exploiting their intrinsic immunomodulatory properties. Different examples of immunomodulatory hydrogels from different origins are provided. © 2024 Elsevier Inc. All rights reserved.