Fig. 2

The potential for mRNA therapeutics and vaccines. A The process of creating novel mRNA drugs from sequence design to clinical translation. The first step is to design an mRNA sequence for a particular disease. Once mRNA is synthesized successfully, the delivery system should be established. Recently, lipid nanoparticles (LNPs) have been proven to be an efficient delivery tool. Animal models and cell-based assays may be used to evaluate the mRNA drug during preclinical testing. The mRNA drug can progress to clinical trials after successful pre-clinical tests. B The administration route is a key consideration when developing mRNA drugs for different diseases. The route might vary depending on the disorder and the type of drug. As an alternative to injections, nasal delivery is a promising method for treating infectious diseases and neurological disorders. Targeted delivery strategies for mRNA. mRNA drugs can be delivered to specific cells, tissues or organs. C–E The delivery of mRNA drugs to specific cells, tissues, or organs can be achieved using targeted mRNA delivery strategies. C Mannosylated lipopolyplexes can be delivered to splenic dendritic cells; D LNPs with different lipid components can be delivered to specific tissues or organs. For example, delivery using LNPs with shorter chains of ionizable lipids induced protein expression in liver, while LNPs with longer chains of ionizable lipids induced mRNA translation in spleen. Moreover, ionizable cationic, permanently cationic or zwitterionic helper lipids can be used for efficient mRNA expression in liver, lung or spleen. E LNPs conjugated with ligands can be used to delivered to leukocytes or tumor cells. For example, LNPs conjugated with antibody against CD5 can be delivered to T cells, while LNPs conjugated with antibody against CD117 can be delivered to hematopoietic stem cells