This invention is a system to deliver poorly permeable molecules into mammalian cells and avoid the problem of degradation.
Introducing specific molecules (cargo) into mammalian cells using the cellular uptake process of endocytosis is often difficult because that molecule can become trapped in late endosomes or lysosomes. These endocytic compartments contain hydrolytic enzymes that can degrade the molecule. Ideally cargo molecules delivered in this way would escape from early/recycling endosomes that have a higher pH and fewer enzymes to break down the molecule. The invention described here allows cargo molecules linked to endosome-targeting groups to be cleaved from the endosome-targeting group and released from early endosomes into the cytosol and nucleus of cells.
This process may be used to transport molecules that have a difficult time reaching the cytosol and nucleus to the desired destination within cells.
This process uses receptor-mediated endocytosis (RME), which utilizes extracellular ligands and surface receptors to form clusters, which then pinch off into intracellular vesicles. This causes the membrane regions to become internalized in the cell within the cytoplasm. The mediating compound then links the cargo to early/recycling endosomes, which are less hydrolytic. The membranes of the early/recycling endosomes are then disrupted using the mediating compound N-Alkyl-3beta-Cholesterylamine, and the disulfide-linked cargo. The linker is then enzymatically cleave or reduced to release the cargo molecule.
This process allows molecules to be delivered into cells without degradation in late endosomes/lysosomes.
Release of drugs or other agents from early/recycling endosomes prevents the drug from being metabolized or trapped allowing for more effective treatment
The invention could also be used as a transport for imaging agents into the cytoplasm and nucleus.