Fig. 3.

SEND mRNA construct induces secretion of hEPO protein into systemic circulation across multiple delivery systems and routes of administration. (A) hEPO mRNA was synthesized via IVT containing either no endogenous signal peptide sequence (NSP-hEPO) or FVII signal peptide sequence in lieu of hEPO’s endogenous signal peptide (FVII-hEPO). Each mRNA was encapsulated into one of three different nanoparticles (LNPs, iPLNPs, and polymer NPs). Each nanoparticle-mRNA formulation was then injected into mice via one of three different ROAs (I.M., I.V., S.Q.). Blood was drawn from mice at 6 h, 24 h, 48 h, and 72 h postinjection, and hEPO protein concentration was quantified via ELISA. (B) In all cases, FVII-hEPO mRNA was able to effectively induce secretion of hEPO protein into blood using multiple delivery systems and ROAs. (C) Area under the curve (AUC) was calculated for every carrier and ROA. Data are presented as mean ± SEM (n = 4 biologically independent animals).