• A Novel Enzyme-mediated Method for Generating Engineered Extracellular Vesicles for Targeted Drug Delivery

In the past few decades, there have been great advances in the development of therapeutics for a range of diseases. However, with the advent of novel therapeutics, there is also a need for a safe, non-immunogenic drug delivery vector capable of delivering therapeutic payloads specifically to diseased cells, thereby increasing therapeutic efficacy and reducing side effects. Extracellular vesicles (EVs) have garnered attention in recent years as a potential ideal vector for drug delivery, taking into account their intrinsic ability to transfer bioactive cargo to recipient cells and their biocompatible nature. The therapeutic potential of natural EVs can be enhanced by engineering EVs via the conjugation of targeting ligands. However, existing methods to engineer target-specific EVs are tedious or inefficient, having to compromise between harsh chemical treatments or transient affinity-based interactions.

The aim of this research project is to develop and characterize a novel enzyme-mediated method for generating target-specific EVs capable of delivering therapeutic cargo to target cells without compromising the endogenous advantageous properties of EVs. EVs engineered using this method were shown to be stably conjugated with targeting moieties at high copy number. The resulting EVs were shown to exhibit antigen-specific targeting capabilities, showing preferential accumulation in target cells both in vitro and in vivo. The functionality of EVs engineered using this approach was demonstrated by the ability of targeting EVs to specifically deliver encapsulated mRNA payloads or antisense oligonucleotides to target cells, resulting in enhanced gene expression or knockdown of target genes, opening up the possibility of safe, targeted gene therapy. Furthermore, the versatility of this approach is highlighted by the ability to target multiple cell surface receptors using a range of targeting moieties including single domain antibodies and monoclonal antibodies. This biocompatible, yet efficient and versatile method for the stable surface modification of EVs opens up avenues for the treatment of a wide variety of diseases while addressing some of the current issues associated with EV-based drug delivery.