| abstract |
The blood-brain barrier (BBB) prevents the passage of molecules weighing more than 500 Da from the blood to the brain. Receptor-mediated transcytosis (RMT) facilitates the passage through the BBB of specific molecules that bind to receptors on the endothelial cells of the brain that form the BBB. An antibody or its fragment binding the receptor for insulin-like growth factor 1, which passes the BBB via RMT, has been detected. An antibody or fragment is used to deliver the load molecule through the BBB, where the load molecule can be a therapeutic or detectable agent. The antibody is a camel VHH obtained by immunizing a llama with an IGF1R polypeptide of 933 amino acids. Humanized forms of camel VHH are also derived. |