L31(Lipid 31)

L31 is identified as a novel, proprietary ionizable cationic lipid that serves as the critical functional component within lipid nanoparticles (LNPs) engineered for CRISPR/Cas9 genome editing in head and neck squamous cell carcinoma (HNSCC). It was selected from a screened library of lipids for its superior performance. LNPs formulated with L31 exhibited excellent physicochemical properties, including a uniform size of 80-100 nm, low polydispersity, and high encapsulation efficiency (>85%) for both Cas9 mRNA and sgRNA. In vitro, L31-based LNPs demonstrated outstanding therapeutic efficacy, achieving approximately 68% gene editing of the oncogene SOX2 and an 88% reduction in cancer cell viability.For in vivo applications, L31-LNPs were further functionalized with anti-EGFR antibodies using the ASSET linker strategy to create targeted nanoparticles (tLNPs). This modification enhanced specific uptake by tumor cells. In a xenograft mouse model, intratumoral injection of these targeted L31-cLNPs co-encapsulating Cas9 mRNA and sgSOX2 led to potent tumor growth inhibition (90%) and a significant increase in survival, with tumor disappearance observed in half of the treated mice. In conclusion, L31 is a highly efficient ionizable lipid that forms the foundation of a potent targeted LNP platform for precise CRISPR-based cancer therapy against solid tumors.