Bioprocess decision support tool for scalable manufacture of extracellular vesicles

Abstract

Newly recognized as natural nanocarriers that deliver biological information between cells, extracellular vesicles (EVs), including exosomes and microvesicles, provide unprecedented therapeutic opportunities. Large-scale and cost-effective manufacturing is imperative for EV products to meet commercial and clinical demands; successful translation requires careful decisions that minimize financial and technological risks. Here, we develop a decision support tool (DST) that computes the most cost-effective technologies for manufacturing EVs at different scales, by examining the costs of goods associated with using published protocols. The DST identifies costs of labor and consumables during EV harvest as key cost drivers, substantiating a need for larger-scale, higher-throughput, and automated technologies for harvesting EVs. Importantly, we highlight a lack of appropriate technologies for meeting clinical demands, and propose a potentially cost-effective solution. This DST can facilitate decision-making very early on in development and be used to predict, and better manage, the risk of process changes when commercializing EV products.

Native and bioengineered extracellular vesicles for cardiovascular therapeutics

“…A clinical study in a human has shown that 10 10 -10 11 EVs was an effective therapeutic dosage to treat one patient with graft-versus-host disease, with multiple administrations of increasing amounts . This dose was estimated based on therapeutic dosages of transplanted MSCs for similar purposes (~10 -10 8 MSCs); however, other studies indicate that clinical application of EVs may require > 10 14 particles per dose 172 . High concentrations of EVs will require the use of bioreactors for cell culture.…”

Scalable Production and Isolation of Extracellular Vesicles: Available Sources and Lessons from Current Industrial Bioprocesses

“…UC‐based workflows are the most common isolation methods since they enable the recovery of relatively high EV yields at the laboratory scale, especially when compared to alternative methods, such as ultrafiltration (UF), size‐exclusion chromatography (SEC), immunoaffinity capture, and polymer precipitation . However, the implementation of UC on a large scale is challenging because of several reasons: i) it requires large and heavy rotors that demand a consistent amount of electrical power to be operated; ii) being a batch process, it has several dead times that reduce the overall productivity; iii) it often copurifies contaminants; iv) it involves high shear forces, causing aggregation and rupture of EVs; v) the composition of the isolated EV mixture is highly sensitive to a variety of experimental settings such as tube type and rotor type, leading to low consistency of EV mixtures obtained with different ultracentrifuges …”

“…The large amount of coisolated proteins and lipid impurities demand a further purification step that would negatively impact the processing time and overall yield . Nevertheless, filtration processes were identified as the most versatile and cost‐effective EV isolation methods for scale up …”

“…Ghosh et al developed synthetic peptides to specifically precipitate EVs through their interaction with heat‐shock proteins. However, independently of the employed precipitation additive, the scalability of this method is intrinsically hampered by the need to remove the additive after EV isolation with further purification steps, reducing significantly the yields and cost‐effectiveness …”

“…One of the most severe bottlenecks of the progress in the field is the typical low EV yield . A liter of conditioned culturing media yields approximately 10 9 –10 11 EVs, an amount that is typically sufficient only for one single test in mice models .…”