Figure 1.

Illustration of the transcytosis of carrier-cargo fusion antibodies through the BBB. Here the illustration uses a bispecific antibody as the example, although other formats also work under the same mechanisms, as shown in Fig. 2. Bispecific antibodies with BBB targeting moiety and cargo bind RMT receptor on the surface of BECs. Then, the antibody-receptor complex undergoes transcytosis to the abluminal side into the brain parenchyma.