Adeno-Associated Virus Self-Assembled with Tannic Acid and Phenylboronic Acid Polymers to Evade Neutralizing Antibodies and Reduce Adverse Events

Adeno-associated viruses (AAVs) are increasingly used in gene therapy to treat debilitating genetic diseases. However, systemically administered AAVs are often inactivated by neutralizing antibodies (NAbs), and high-dose administration of AAVs causes hepatotoxicity, which limits their effectiveness. To address these challenges, we present a sequential assembly technique based on tannic acid (TA) and phenylboronic acid-conjugated polymers to form AAV-loaded ternary complexes having a core-shell structure with an average diameter of 60 nm in an aqueous solution. Since TA coats AAVs and forms boronate esters with boronic acids on polymers, AAV serotype 9 (AAV9, an average diameter of 25 nm) was successfully packaged into a core compartment surrounded by polymer chains forming a protective shell to evade inactivation by NAbs. The intravenously injected ternary complexes successfully evade NAbs and suppress hepatotoxicity by minimizing liver accumulation. Meanwhile, the ternary complex exhibited efficient gene transduction into cells by releasing AAV9 intracellularly and maintained the blood-brain barrier (BBB) permeability of AAV9 to target brain cells, thereby enhancing brain/liver transduction selectivity 20-fold compared to AAV9 alone. Moreover, combining this assembly technique with a microbubble-focused ultrasound (MB-FUS) system for noninvasive BBB opening improves its gene transduction efficiency into the brain by more than 6-fold and further increases brain/liver transduction selectivity. Our supramolecular approach combined with a medical device represents a significant advancement in AAV-based gene therapy.