RNA and Protein Delivery by Cell‐Secreted and Bioengineered Extracellular Vesicles

Abstract

Extracellular vesicles (EVs) are carriers of biological signals through export and delivery of RNAs and proteins. Of increasing interest is the use of EVs as a platform for delivery of biomolecules. Preclinical studies have effectively used EVs to treat a number of diseases. Uniquely, endogenous machinery within cells can be manipulated in order to produce desirable loading of cargo within secreted EVs. In order to inform the development of such approaches, an understanding of the cellular mechanisms by which cargo is sorted to EVs is required. Here, the current knowledge of cargo sorting within EVs is reviewed. Here is given an overview of recent bioengineering approaches that leverage these advances. Methods of externally manipulating EV cargo are also discussed. Finally, a perspective on the current challenges of EVs as a drug delivery platform is offered. It is proposed that standardized bioengineering methods for therapeutic EV preparation will be required to create a well-defined clinical product.

Extracellular vesicles released by hypoxia‐induced tumor‐associated fibroblasts impart chemoresistance to breast cancer cells via long noncoding RNA H19 delivery

“…5,6 EVs are membrane-released vesicles acting as transporters of proteins, lipids, microRNAs (miRNAs or miRs), and long noncoding RNAs (lncRNAs), such as H19. 7,8 H19 is a research focus due to its ectopic expression in various types of human malignant tumors where it exerts oncogenic roles to enhance cell proliferation, invasion, migration, epithelial-mesenchymal transition (EMT), and metastasis as well as impairing chemo and radiotherapy in tumorigenesis, including BC. 9,10 The expression of H19 in paclitaxel (TAX)-resistant TNBC cells is significantly higher than that in TAX-sensitive cells, and H19 knockdown can increase the sensitivity of TNBC cells to TAX by mediating the AKT signaling pathway.…”

“…Increasing evidence has shown that BC exposed to hypoxia (HP) tends to release more extracellular vesicles (EVs) 5,6 . EVs are membrane‐released vesicles acting as transporters of proteins, lipids, microRNAs (miRNAs or miRs), and long noncoding RNAs (lncRNAs), such as H19 7,8 . H19 is a research focus due to its ectopic expression in various types of human malignant tumors where it exerts oncogenic roles to enhance cell proliferation, invasion, migration, epithelial–mesenchymal transition (EMT), and metastasis as well as impairing chemo and radiotherapy in tumorigenesis, including BC 9,10 .…”

Standardization Approaches for Extracellular Vesicle Loading with Oligonucleotides and Biologics

“…[163] Alternatively, the EV surface exhibits diverse options for functionalization with targeting moieties. [64,39,164,165]…”

Membrane translocation of folded proteins

“…Enveloped viruses adopt the reverse process, membrane fusion with the plasma or endosomal membrane, to transfer their proteins and genetic materials into eukaryotic cells ( 163 ). Researchers have also encapsulated protein and nucleic acid cargos into membrane vesicles and delivered them into the cell ( 164 ).…”