BmTACs Ride Age-Upregulated Transcytosis to Deliver a ROS-Activated DAPK1 Degrader into the Brain
- Brain delivery is the main barrier for degraders in neurodegeneration; BmTACs attach a macrocyclic peptide shuttle that exploits caveolae-mediated transcytosis, which rises with age in brain endothelium.
- A reactive-oxygen-species-responsive cage on the VHL ligand keeps the PROTAC inactive until it reaches high-ROS tissue.
- The platform is designed to remove activated DAPK1 selectively in the aging brain.
💡 Points
Two gating layers, shuttle for entry and ROS cage for activation, is clever systems design, but it moves the problem from medicinal chemistry to conjugate CMC and PK. I'd look hard at the unmasked-PROTAC fraction in periphery and at the shuttle's dependence on aged-endothelium biology, which could narrow the patient window. A real step for CNS degraders if the in vivo data hold up.