Negatively charged phospholipids doped liposome delivery system for mRNA with high transfection efficiency and low cytotoxicity

Messenger RNA (mRNA) has become one of the most potential drugs in recent years. However, efficient and safe delivery of fragile and easily degradable mRNA is a major challenge. Appropriate delivery system (DS) determines the final effect of mRNA. Cationic lipids play a crucial and decisive role in the entire DS, but also cause huge biosafety problems due to the high toxicity. In this study, a new DS for mRNA delivery that combines negatively charged phospholipids was developed in order to neutralize the positive charge and thus increase the safety. Further, the factors affecting mRNA transfection from cell to animal were investigated. The mRNA DS with optimum condition of lipid composition, proportions, structure, and transfection time was synthesized. Adding an appropriate amount of the anionic lipid to liposomes could increase the safety while maintaining the original transfection efficiency. For transporting mRNA in vivo, requirements regarding the mRNA encapsulation and releasing rate should be further considered to optimize DS design and preparation.

Automated summary

Messenger RNA (mRNA) has great potential as a drug, but efficient and safe delivery remains a challenge. This study developed a new mRNA delivery system using negatively charged phospholipids to neutralize the positive charge and increase safety. Factors affecting mRNA transfection were investigated, and an optimal lipid composition, proportions, structure, and transfection time were determined. Adding an appropriate amount of anionic lipid to liposomes increased safety without compromising transfection efficiency. Further considerations are needed to optimize the design and preparation of the delivery system for mRNA encapsulation and releasing rate during in vivo transportation.