Unsaturated, Trialkyl Ionizable Lipids are Versatile Lipid-Nanoparticle Components for Therapeutic and Vaccine Applications

Adv Mater. 2023 Apr;35(15):e2209624. doi: 10.1002/adma.202209624. Epub 2023 Mar 5.

Abstract

Lipid nanoparticles (LNPs) have proven a successful platform for the delivery of nucleic acid (NA)-based therapeutics and vaccines, with the ionizable lipid component playing a key role in modulating potency and tolerability. Here, a library of 16 novel ionizable lipids is screened hypothesizing that short, branched trialkyl hydrophobic domains can improve LNP fusogenicity or endosomal escape, and potency. LNPs formulated with the top-performing trialkyl lipid (Lipid 10) encapsulating transthyretin siRNA elicit significantly greater gene silencing and are better tolerated than those with the benchmark Onpattro lipid DLin-MC3-DMA. Lipid 10 also demonstrates superior liver delivery of mRNA when compared to other literature ionizable lipids, is well tolerated, and successfully repeat-doses in nonhuman primates. In a prime-boost hemagglutinin rodent vaccine model, intramuscular administration of Lipid-10 LNP elicits comparable or better antibody titers to the SM-102 and ALC-0315 lipid compositions used in the U.S. Food and Drug Administration approved mRNA COVID vaccines. These data suggest that Lipid 10 is a particularly versatile ionizable lipid, well-suited for both systemic therapeutic and intramuscular vaccine applications and able to successfully deliver diverse NA payloads.

Keywords: ionizable lipids; lipid nanoparticles; nanotechnology; nucleic acid; therapeutics; vaccines.

MeSH terms

  • Animals
  • COVID-19*
  • Lipids / chemistry
  • Nanoparticles* / chemistry
  • RNA, Messenger
  • RNA, Small Interfering / chemistry

Substances

  • Lipid Nanoparticles
  • RNA, Small Interfering
  • Lipids
  • RNA, Messenger