HY-501 is a next-generation cationically ionizable lipid engineered for high-efficiency RNA delivery developed by Biontech. Formulated at 40–50 mol% in lipid nanoparticles (LNPs) alongside DSPC, cholesterol, and polysarcosine-conjugated lipid C14pSar23, HY-501 yields uniform, stable particles (80–100 nm) with >90% RNA encapsulation. It demonstrates superior in vivo performance: driving 2-fold higher protein expression than benchmark lipids (EA-405/HY-405) in muscle tissue, minimizing off-target liver accumulation, and reducing immunogenic risks (near-zero complement activation and <5% hemolysis). Preclinically, HY-501-based LNPs encoding SARS-CoV-2 spike protein elicit potent neutralizing antibodies and T-cell responses, underscoring its utility in precision vaccines. Its combination of scalable synthesis, exceptional transfection efficiency, and biosafety establishes HY-501 as a transformative vector for therapeutic RNA delivery.
