The inventions provided herein generally relate to compositions and methods for controlling response of immune cells to at least one stimulus or condition (e.g., but not limited to, tissue damage, an implantable device and/or a cytokine) in vitro or in vivo. The compositions described herein comprise a biomaterial (e.g., a silk fibroin-based matrix) comprising at least one immune cell-modulating agent in an effective amount sufficient to selectively alter activation state of at least one type of immune cells (e.g., but not limited to macrophages and dendritic cells). Accordingly, in some embodiments, the compositions and methods described herein can be used to selectively skew macrophages to M1 phenotype and/or M2 phenotype and thereby control the inflammatory and/or regenerative responses of the macrophages, e.g., to repair and/or regenerate a target tissue.
