Figure 6.

Mn²⁺ was used as an inducer to polarize macrophages into anti-tumor M1 macrophages. At the same time, the membrane is modified with azide groups through the inherent biosynthesis and metabolic incorporation of phospholipids. Then the azide modified M1 Exo was coupled with dibenzocyctocene (DBCO) modified anti-CD47 antibody (aCD47) and pH-sensitive anti-signal regulatory protein alpha (SIRPα) antibody (aSIRPα). After acid-induced division, antibodies are separated from exosomes, which repolarize M2-type macrophages into M1-type macrophages. ACD47 acts on CD47 overexpressed by tumor cells to resist the “don’t eat me” signal. Meanwhile, aSIRPa acts on SIRPA of macrophages to prevent phagocytic cells from losing their phagocytic ability. And then the phagocytes will eat the tumor cells.