Lipid CAD9 (3-A2-7b is a cationic degradable (CAD) lipid. 3-A2-7b formulated LNP, LNP-CAD9, can deliver FLuc mRNA to the lungs in vivo. LNP-CAD9 co-delivering Cas9 mRNA/VEGFR2 single guide RNA (sgRNA) effectively induces VEGFR2 knock out in lung endothelial cells of female mice.

A3T2C7 (CP-LC-1495) is a biodegradable ionizable lipid featuring three β-propionate linkers and an azetidine polar head, formulated in four-component LNPs. It demonstrates exceptional lung-targeted mRNA delivery with 97.1% selectivity and high protein expression (1.21×10⁸ p/s) in mice. Its slightly positive zeta potential (~3.5 mV) correlates with lung tropism, likely mediated by protein corona enrichment of vitronectin and prothrombin. The β-propionate structure enables pH-sensitive biodegradability for enhanced endosomal escape while maintaining low cytotoxicity (>90% cell viability). This lipid enables organ-specific mRNA delivery without permanently charged additives, outperforming conventional SORT strategies in selectivity and expression efficiency.

The AA15 lipid, an amino acid-derived ionizable lipid, integrates a carboxylic acid-containing headgroup and biodegradable branched ester tails (R2) to enhance mRNA delivery. Optimized as AA15V LNP, it exhibits a hydrodynamic diameter of 102.3 ± 4.1 nm, low polydispersity (PDI <0.15), and slightly positive zeta potential (+4–6 mV), enabling efficient tumor-targeted delivery. With a pKa ~6.1–6.4, AA15V ensures protonation in acidic endosomes, promoting mRNA release. It achieves >85% mRNA encapsulation efficiency, critical for stable saRNA delivery. In vitro, AA15V LNP-sSE-SCTs induced sustained SE-SCT expression (69% H-2Kb+β2m+ B16F10 cells at 72 h), outperforming mRNA formulations. In vivo, a single intratumoral dose of AA15V LNP-sSE-SCTs suppressed tumor growth by 22-fold in vaccinated mice, synergizing with checkpoint inhibitors (anti-PD-1/CTLA-4) for complete regression in 28.6% of lymphoma models. Ex vivo, AA15V enabled SE-SCT expression in human glioblastoma (7.1% CD45− cells) and lung cancer samples (5.8–8.7%), underscoring clinical potential. Key data: pKa ~6.3; encapsulation: 85–89%; zeta: +4–6 mV; size: 102.3 ± 4.1 nm.