From Promise to Reality: Bioengineering Strategies to Enhance the Therapeutic Potential of Extracellular Vesicles

Abstract

Extracellular vesicles (EVs) have been the focus of great attention over the last decade, considering their promising application as next-generation therapeutics. EVs have emerged as relevant mediators of intercellular communication, being associated with multiple physiological processes, but also in the pathogenesis of several diseases. Given their natural ability to shuttle messages between cells, EVs have been explored both as inherent therapeutics in regenerative medicine and as drug delivery vehicles targeting multiple diseases. However, bioengineering strategies are required to harness the full potential of EVs for therapeutic use. For that purpose, a good understanding of EV biology, from their biogenesis to the way they are able to shuttle messages and establish interactions with recipient cells, is needed. Here, we review the current state-of-the-art on EV biology, complemented by representative examples of EVs roles in several pathophysiological processes, as well as the intrinsic therapeutic properties of EVs and paradigmatic strategies to produce and develop engineered EVs as next-generation drug delivery systems.

Optimized operation of a controlled stirred tank reactor system for the production of mesenchymal stromal cells and their extracellular vesicles

“…The bioreactor-based platform developed herein will allow to transform laboratory-based protocols into robust MSC and MSC-EVs manufacturing processes, with a tight control over the culture process and significant reduction of the production times. By addressing the manufacturing challenges of cell-based products, this technology is expected to facilitate translation of MSC therapies and likely to impact the development of therapeutic strategies employing MSC-EVs, which could rapidly progress towards clinical studies exploiting their potential as intrinsic therapeutics or as drug delivery systems (de Almeida Fuzeta et al, 2022;Syromiatnikova et al, 2022). In addition, this platform could be applied to the production of EVs from other parental cells lines (i.e.…”

“…The universally used expression "EVs" comprises all vesicle subtypes (exosomes, microvesicles and apoptotic bodies) and is a highly heterogeneous pool concerning size range (30-5000 nm), origin, content (proteins, lipids, genetic material and organelles such as mitochondria), biochemical and biophysical features, and biological functions. Compared to cell therapies, the use of EVs as cell-free therapeutic products presents several potential advantages namely: (i) EVs are relatively safer, as they are completely non-replicative and not mutagenic (Elsharkasy et al, 2020); (ii) EVs have also a low risk of inducing microvasculature obstruction upon administration due to their smaller size; (iii) EVs have long circulating half-life and the ability to cross the blood brain barrier (BBB) (Cerri et al, 2015;Moon et al, 2019); (iv) EVs have a simpler composition than parental cells, although still complex and with a bioactive cargo; (v) EVs can used as delivery systems with increased efficacy and homing capacity (de Almeida Fuzeta et al, 2022;Katsuda et al, 2013;Pascucci et al, 2014); (vi) EVs as non-living biological products are more resistant to manipulation than living cells; (vii) the possibility of using reduced doses in vivo to achieve a therapeutic response, as EVs can evade phagocytes (Baglio et al, 2015); and (viii) EVs can be potentially stored with no need of potentially toxic cryoprotectants at -20°C for six months without loss of their biochemical activity (Alvarez-Erviti et al, 2011;Sun et al, 2010;Webber & Clayton, 2013). Overall, the regulatory aspects for producing EV-based products for therapeutic strategies is expected to be less complicated than for any therapy based on in vitro expanded cells.…”

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

“…However, each step of scalable EV manufacturing under GMP compliance is still exposed to several challenges ( 163 , 164 ). These challenges exist not only in upstream and downstream stages ( 165 , 166 ) of EV production and isolation, such as cell culture and purification steps, respectively, but also during EV storage ( 108 ), quality control ( 167 ), and functional evaluation steps ( 148 , 168 ).…”

“…Clinical translation of the EVs is affected by different issues, including isolation, purification, standardization, yield, and functional heterogeneity (287,302). Accordingly, a field for EV engineering has emerged to augment their natural properties (165) and recapitulate their function in semi-synthetic and synthetic EVs. In recent work, Xu et al introduced a novel peptide-equipped EV platform to enhance the efficiency of EV penetration and oligonucleotide loading capacities (303).…”

Bioengineered Mesenchymal-Stromal-Cell-Derived Extracellular Vesicles as an Improved Drug Delivery System: Methods and Applications

“…In fact, EVs seem to be internalized more efficiently and deliver their therapeutic agent several orders of magnitude more efficiently than synthetic nanoparticles [ 5 , 6 ]. EVs can be further bioengineered to harbour exogenous cargoes or to alter surface properties improving their therapeutic efficacy and target-specificity [ 7 , 8 ].…”