Hybrid Milk Extracellular Vesicles as Potential Systems for Oral Delivery of siRNA

Oral administration of RNA is currently not possible and current approaches for RNA delivery by injection are not suitable for the oral route. In this work, novel bioinspired nanoparticles for oral delivery of RNA therapies are reported. Specifically, the fabrication of hybrid nanovesicles (“hybridosomes”) based on bovine milk extracellular vesicles (mEVs) and liposomes is reported. Hybridosomes are fabricated using two related methods based on freeze-thawing of mEVs and cationic liposomes. The systems are 180–230 nm and demonstrated efficient loading of small interfering (siRNA) cargo. Hybridosomes exhibit significantly lower cytotoxicity in intestinal Caco-2 cells compared to cationic liposomes and superior stability in a fed-state simulated intestinal fluid compared to liposomes. Furthermore, these systems significantly increase the transport of siRNA across in vitro intestinal model. Finally, hybridosomes loaded with siRNA successfully induce transfection in J774A.1 macrophages. Overall, the results show that the hybrid systems fabricated here offer potential for oral delivery of RNA therapeutics.