GalNAc End-Capped Poly(β-amino ester)s with Screened Side Chains for Efficient Gene Delivery

Plasmids are widely used gene vectors in gene therapy, yet their efficient delivery remains a major challenge for achieving optimal therapeutic outcomes. Recently, poly(β-amino esters) (PBAEs) have emerged as promising carriers for non-viral gene delivery due to their tunable structures and high delivery efficiency. Nonetheless, the cationic nature of PBAEs raises toxicity concerns, and their lack of tissue-specific targeting capability limits their clinical application. Herein, a novel PBAE for efficient plasmid delivery is constructed, which contains disulfide bonds in the backbone and N-acetylgalactosamine (GalNAc) moieties at the terminals (GalNAc-PBAEs). To address the potential reduction in nucleic acid condensing capacity caused by end-capping PBAE with GalNAc, the commonly used end-capping amines in conventional PBAE are employed as monomers to create GalNAc-PBAEs with tertiary amine side chains. Through side-chain screening, the optimized GalNAc-PBAE exhibits enhanced transfection efficiency, surpassing that of the conventional top-performing PBAE, C28-E7, and rivaling the commercial transfection reagent Lipo2000. Importantly, the GalNAc moieties enable the plasmid-PBAE polyplex to efficiently target the liver. In a mouse model with acute liver fibrosis, the efficient delivery and expression of a representative plasmid encoding HGF significantly mitigate liver fibrosis and improve liver function, demonstrating the potential of the designed PBAE in gene therapy.