Bispecific antibody capable of being combined with immune cells to enhance tumor killing capability, and preparation method therefor and application thereof

A bispecific antibody, comprising a first antibody moiety that binds to an antigen expressed on an effector T cell and a second antibody moiety that binds to an antigen expressed on a cancer cell, wherein the first antibody moiety and the second antibody moiety are connected by a biodegradable nanomaterial, and

• wherein the antigen expressed on the effector T cell is CD3 and the antigen expressed on the target cell is Muc1, or
• wherein the antigen expressed on the effector T cell is CD3 and the antigen expressed on the target cell is CD19, or
• wherein the antigen expressed on the effector T cell is CD3 and the antigen expressed on the target cell is CD20, or
• wherein the antigen expressed on the effector T cell is CD3 and the antigen expressed on the target cell is CD33, or
• wherein the antigen expressed on the effector T cell is CD3 and the antigen expressed on the target cell is Her2, or
• wherein the antigen expressed on the effector T cell is CD8 and the antigen expressed on the target cell is Muc1, or
• wherein the antigen expressed on the effector T cell is CD3 and the antigen expressed on the target cell is CD38.