Progress on Modulating Tumor‐Associated Macrophages with Biomaterials

Tumor‐associated macrophages (TAMs) are a complex and heterogeneous population of cells within the tumor microenvironment. In many tumor types, TAMs contribute toward tumor malignancy and are therefore a therapeutic target of interest. Here, three major strategies for regulating TAMs are highlighted, emphasizing the role of biomaterials in these approaches. First, systemic methods for targeting tumor‐associated macrophage are summarized and limitations to both passive and active targeting approaches considered. Second, lessons learned from the significant literature on wound healing and macrophage response to implanted biomaterials are discussed with the vision of applying these principles to localized, biomaterial‐based modulation of tumor‐associated macrophage. Finally, the developing field of engineered macrophages, including genetic engineering and integration with biomaterials or drug delivery systems, is examined. Analysis of major challenges in the field along with exciting opportunities for the future of macrophage‐based therapies in oncology are included. Tumor‐associated macrophages (TAMs) are significant drivers of tumor progression. Key strategies that are reported to modulate TAM behavior in cancer using biomaterials are discussed, highlighting challenges and new opportunities. The role of macrophages in wound healing is also discussed and lessons that can be applied to cancer therapies are derived.