Tetrahydropyrimidine Ionizable Lipids for Efficient mRNA Delivery

Area of Science:

• Biotechnology and Nanomedicine
• Drug Delivery Systems
• Molecular Biology

Background:

• Lipid nanoparticles (LNPs) are crucial for messenger RNA (mRNA) delivery in gene therapy.
• Current LNP platforms face challenges in endosomal escape and mRNA release, often requiring complex ionizable lipid synthesis.
• Developing efficient and scalable ionizable lipids is key for advancing nucleic acid-based therapies.

Purpose of the Study:

• To synthesize a library of novel ionizable lipids with a tetrahydropyrimidine (THP) backbone using a facile one-pot multicomponent reaction (MCR).
• To evaluate the efficacy and safety of THP-based LNPs for mRNA delivery in vitro and in vivo.
• To explore the potential of THP LNPs in targeted gene editing applications.

Main Methods:

• A catalyst-free, one-pot MCR was used to synthesize 26 THP ionizable lipids.
• THP lipids were formulated into LNPs with luciferase mRNA for in vitro transfection and in vivo studies.
• Particle size, ζ-potential, encapsulation efficiency, transfection efficiency, protein expression, toxicity, and gene editing capabilities were assessed.

Main Results:

• A library of 26 THP ionizable lipids was synthesized in 3 hours.
• THP LNPs exhibited tunable properties and high encapsulation efficiencies.
• THP1 LNPs demonstrated high in vitro and in vivo transfection efficiency, comparable to benchmark lipids (MC3).
• Optimized THP1 LNPs showed sustained protein expression and successful intravenous delivery with minimal toxicity.
• THP1 LNPs facilitated gene editing in mouse liver tissues.

Conclusions:

• A novel, facile MCR enables rapid synthesis of THP ionizable lipids for enhanced mRNA delivery.
• THP1 LNPs represent a promising platform for mRNA therapeutics, including vaccines and CRISPR/Cas9 gene editing.
• These findings support the clinical translation potential of THP-based LNP technology for various therapeutic applications.