DNA origami assembled spheroid for evaluating cytotoxicity and infiltration of chimeric antigen receptor macrophage (CAR-M).

Chimeric antigen receptor (CAR) T-cell therapies have shown remarkable results in patients with hematological malignancies. However, their success in treating solid tumors has been limited. As an alternative candidate for the CAR therapy, CAR-macrophages (CAR-M) have demonstrated activation and phagocytosis directed by tumor-associated antigen (TAA), showing promise in the treatment of solid tumors. Nevertheless, the mechanisms by which CARs direct tumor chemotaxis and invasion of CAR-M remain poorly understood. In this study, we aim to investigate the role of CARs in CAR-M attachment and infiltration using 3D tumor spheroids, which were created by utilizing a novel self-assembling nucleic acid nanostructure decorated living cells (NAC). Our results demonstrated that CAR-M exhibited higher invasion and killing capacity in 2D model and 3D tumor spheroids. In summary, the 3D NAC assembled tumor spheroid model provides a suitable platform for target screening and pharmacodynamic evaluation of CAR-M.