In situ programming of unconventional T cells.

Unconventional T cells (UTCs), including γδ T cells, mucosal-associated invariant T cells, and natural killer T cells, recognize conserved nonpeptide antigens through semi-invariant T cell receptors in an human leukocyte antigen-independent manner, making them attractive candidates for broadly applicable immunotherapies. However, their clinical translation remains limited by poor spatiotemporal control of activation, functional exhaustion, and insufficient tissue homing in vivo, particularly in solid tumors. Biomaterial-based delivery systems provide a promising strategy to overcome these barriers by enabling localized and sustained delivery of UTC ligands, cytokines, and nucleic acids within diseased tissues. Through precise in situ programming of UTC responses, these platforms may enhance therapeutic efficacy and safety. This review summarizes current biomaterial-based strategies and discusses emerging opportunities for in situ UTC programming in human cancers.