Abstract

Messenger RNA (mRNA) has emerged as an attractive therapeutic molecule for a plethora of clinical applications. For in vivo functionality, mRNA therapeutics require encapsulation into effective, stable, and safe delivery systems to protect the cargo from degradation and reduce immunogenicity. Here, a bioengineering platform for efficient mRNA loading and functional delivery using bionormal nanoparticles, Extracellular Vesicles (EVs), is established by expressing a highly specific RNA-binding domain fused to CD63 in EV producer cells stably expressing the target mRNA. The additional combination with a fusogenic endosomal escape moiety, VSVg, enables functional mRNA delivery in vivo at doses substantially lower than currently used clinically with synthetic lipid-based nanoparticles. Importantly, the application of EVs loaded with effective cancer immunotherapy proves highly effective in an aggressive melanoma mouse model. This technology addresses substantial drawbacks currently associated with EV-based nucleic acid delivery systems and is a leap forward to clinical EV applications. Graphical Abstract(Figure created using BioRender) O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=189 SRC="FIGDIR/small/533081v3_ufig1.gif" ALT="Figure 1"> View larger version (56K): org.highwire.dtl.DTLVardef@140058eorg.highwire.dtl.DTLVardef@2ceaccorg.highwire.dtl.DTLVardef@eafd52org.highwire.dtl.DTLVardef@19d4019_HPS_FORMAT_FIGEXP M_FIG C_FIG