Cell‐specific targeting of extracellular vesicles through engineering the glycocalyx

Abstract

Extracellular vesicles (EVs) are promising carriers for the delivery of a variety of chemical and biological drugs. However, their efficacy is limited by the lack of cellular specificity. Available methods to improve the tissue specificity of EVs predominantly rely on surface display of proteins and peptides, largely overlooking the dense glycocalyx that constitutes the outermost layer of EVs. In the present study, we report a reconfigurable glycoengineering strategy that can endogenously display glycans of interest on EV surface. Briefly, EV producer cells are genetically engineered to co‐express a glycosylation domain (GD) inserted into the large extracellular loop of CD63 (a well‐studied EV scaffold protein) and fucosyltransferase VII (FUT7) or IX (FUT9), so that the engineered EVs display the glycan of interest. Through this strategy, we showcase surface display of two types of glycan ligands, sialyl Lewis X (sLeX) and Lewis X, on EVs and achieve high specificity towards activated endothelial cells and dendritic cells, respectively. Moreover, the endothelial cell‐targeting properties of sLeX‐EVs were combined with the intrinsic therapeutic effects of mesenchymal stem cells (MSCs), leading to enhanced attenuation of endothelial damage. In summary, this study presents a reconfigurable glycoengineering strategy to produce EVs with strong cellular specificity and highlights the glycocalyx as an exploitable trait for engineering EVs.

Engineering exosomes to reshape the immune microenvironment in breast cancer: Molecular insights and therapeutic opportunities

“…This modification results in the production of exosomes that carry Lewis X ligands. The inclusion of Lewis X allows these exosomes to selectively interact with DC‐specific intercellular adhesion molecule‐3 grabbing non‐integrin expressed on the surface of DCs, thereby conferring a heightened specificity for activated DCs 30 . In addition, exosomes modified with CD40 ligand (CD40L) can specifically target DCs expressing CD40 on their surface, enhancing DC targeting through CD40L‐CD40 interactions 31 .…”

Targeted exosome-based nanoplatform for new-generation therapeutic strategies

“…Traditionally, this method is used to effectively express peptides and proteins on the surfaces of exosomes by fusing the gene sequence of a polypeptide or protein to that of a specific exosome protein. Recently, researchers have successfully added glycans to the surface of exosomes to achieve targeting [152]. The construction of plasmid or viral vectors is required in the above process.…”

“…The fusion of the small extracellular loop of CD63 with Apo-A1 facilitates the exosome delivery of miRNA-26a to SR-B1expressing HepG2 cells, thus inhibiting hepatocarcinoma proliferation and migration [147]. According to another study, the fusion of the large extracellular loop of CD63 with a glycosylation domain facilitates the binding of exosomes to Sialyl Lewis-X (sLeX, a tetrasaccharide glycan), thus enhancing the ability of exosomes to target inflammatory cells [152]. In this study, researchers have developed a novel glycoengineering strategy to display sLeX on the surfaces of exosomes, which has prompted the use of different glycosyltransferases to load different kinds of glycosyl modifications to achieve the targeting of different cells.…”

Extracellular vesicles and their cells of origin: Open issues in autoimmune diseases

“…Regarding the selective EV uptake, proteins and glycoproteins on the surface of EV and the recipient cell mediate EV-cell interactions. Hence, most strategies that were applied to increase the tissue specificity of EVs are trying to reconfigure the surface glycoproteins of the vesicles ( 231 ). Through various targeting mechanisms, EVs interact with recipient cells to transmit selective biological information.…”