Bioengineered Extracellular Membranous Nanovesicles for Efficient Small‐Interfering RNA Delivery: Versatile Platforms for Stem Cell Engineering and In Vivo Delivery

Naturally derived nanovesicles secreted from various cell types and found in body fluids can provide effective platforms for the delivery of various cargoes because of their intrinsic ability to be internalized for intercellular signal transmission and membrane recycling. In this study, the versatility of bioengineered extracellular membranous nanovesicles as potent carriers of small‐interfering RNAs (siRNAs) for stem cell engineering and in vivo delivery has been explored. Here, exosomes have been engineered, one of the cell‐derived vesicle types, to overexpress exosomal proteins fused with cell‐adhesion or cell‐penetrating peptides for enhanced intracellular gene transfer. To devise a more effective delivery system with potential for mass production, a new siRNA delivery system has also been developed by artificially inducing the outward budding of plasma membrane nanovesicles. Those nanovesicles have been engineered by overexpressing E‐cadherin to facilitate siRNA delivery to human stem cells with resistance to intracellular gene transfer. Both types of engineered nanovesicles deliver siRNAs to human stem cells for lineage specification with negligible cytotoxicity. The nanovesicles are efficient in delivering siRNA in vivo, suggesting feasibility for gene therapy. Cell‐derived, bioengineered nanovesicles used for siRNA delivery can provide functional platforms enabling effective stem cell therapeutics and in vivo gene therapy.