L1 is a biodegradable, branched self-immolative lipid optimized for high-efficiency mRNA delivery. Its disulfide-based architecture enables rapid glutathione-triggered degradation in the cytosol (liver half-life: 4.2 days), promoting rapid clearance while maintaining serum stability. In vivo, L1 achieves exceptional mRNA translation, producing twice the hEPO protein levels of the clinically approved MC3 lipid at 0.1 mg/kg. Its apparent pKa (6.57) facilitates efficient endosomal escape without compromising safety: even at 5 mg/kg, L1 causes no significant body weight loss or sustained inflammation. Structural features (C7 alkyl tails, carbamate linker) balance potency and biodegradability, making L1 ideal for mRNA vaccines and protein-replacement therapies.
