MMAEX Ligands for Full and Empty AAV Capsid Separation

The patent replaces the mechanical centrifugation system with a chromatographic system using immobilized ligands. Instead of using centrifugal force to separate capsids based on density, the invention uses chemical interactions between ligands (such as polyethyleneimine, chitosan, or other cationic polymers) and the negatively charged surface of viral capsids to achieve separation. This substitution enables scalable purification through column chromatography while maintaining high purification effectiveness.

The patent exploits differences in surface charge parameters between full and empty capsids to achieve separation. By adjusting pH, ionic strength, and ligand density, the method optimizes binding conditions to selectively retain full capsids while allowing empty capsids to pass through. This parameter-based approach enables scalable purification without requiring complex centrifugation equipment.

The patent uses composite ligand systems combining multiple functional groups (e.g., cationic polymers with hydrophobic moieties, or combinations of different charged groups) to enhance separation precision. These composite materials provide multiple interaction modes with the capsid surface, improving the ability to distinguish between full and empty capsids while maintaining a relatively simple chromatographic process.

The patent modifies specific regions of the purification medium with targeted ligands that have enhanced affinity for full capsids. By creating localized zones of high binding capacity on the chromatographic support, the method achieves superior separation precision without complicating the overall process flow.