306Oi10

– 306Oi10 is a branched-chain ionizable lipidoid and may be useful in the generation of lipid nanoparticles (LNPs). 306Oi10 ionizable lipids tail is isodecyl acrylate, affording the lipid tail a carbon branch, which confers significant improvement of the mRNA deliver efficiency. Compared with the straight-tailed 306O10, the 306Oi10 with carbon branches at the lipid tail generates more powerful surface ionization at late endosomal pH of 5.0 to improve the delivery efficiency of mRNA. The studies showed that 306Oi10 iLNPs significantly promoted mRNA expression in liver (more than 10- fold).306Oi10 iLNPs could induce stronger protein expression than two benchmark lipids, C12-200 and DLin-MC3-DMA. The total organ protein expression produced by 306Oi10 iLNPs was threefold higher than MC3 and over 20-fold higher expression than C12-200. The 306Oi10 iLNPs could codeliver three distinct mRNAs (luciferase, mCherry, and erythropoietin), or deliver Cas9 mRNA and single guide RNA (sgRNA) separately. Besides, 306Oi10 iLNPs have the potential of mRNA therapy for hepatocellular carcinoma, because they could target malignant hepatocytes, endothelial cells, and Kupffer cells simultaneously. To enable 306Oi10 iLNPs to deliver mRNA to extrahepatic organs, charged phospholipids were used in place of neutral phospholipids. The substitution of DOPE with DOTAP increased the positive surface charge of iLNPs at pH 7 about fivefold and changed the protein expression ratio of liver/lung from 36:1 to 1:56. Similarly, the substitution of DOPE with PS decreased the positive charge and changed the protein expression ratio of liver/spleen from 8:1 to 1:3. Further, the lung-target of DOTAP was better than that of neutral or anionic lipids, which might reduce immune cells infiltration in the lung.