KC-34 (S,S)

KC‑34 (SPC‑A9) is a novel stereopure, diketopiperazine-based ionizable cationic lipid engineered to overcome traditional liver-restricted delivery, achieving balanced multi-organ mRNA transfection. Upon systemic intravenous administration, its precisely optimized chiral configuration allows the lipid nanoparticles (LNPs) to efficiently cross endothelial barriers and target the bone marrow, offering immense therapeutic potential for in vivo hematopoietic stem cell gene editing. Concurrently, KC-34 mediates robust and long-lasting protein expression in the spleen and lungs with minimal hepatic off-target toxicity. Its stable structure provides excellent biocompatibility and high in vivo tolerance, making it ideal for systemic, multi-dose mRNA therapies.