Evidence implicating the pivotal role of Extracellular Vesicles (EVs) in stimulation of tissue regeneration is rapidly gaining pace. EVs have been explored as therapeutically capable nanodrugs for prospective clinical studies<super-script>1<super-script>. However, with the current state of affairs, EV production conforming FDA regulations is still an uphill task. ZenBio Inc., was founded in 1995 with its main focus on providing regulated and quality, compliant, customized cell-based solutions to several companies and academic institutions. These cell-based solutions have centered on diabetes, lung cancer, Chronic Kidney Disease (CKD), and other chronic and devastating diseases. Dr. John Ludlow, Executive Director (Regenerative Medicine) at ZenBio, Inc. recalls, “After attending quite a few stem cell therapy meetings, I thought the EV field was going to pick up momentum in next couple of years”, when asked about the origin of his inclination towards the EV domain. ZenBio has 3 NIH-sponsored Small Business Innovation Research (SBIR) grants to investigate the role of exosomes, a smaller subset of EVs, in tendinopathy and wound healing. Dr. Ludlow talked to us about the current status and factors affecting EV production, including isolating exosomes from bioreactors, subsequent quality control, as well as short- and long-term clinical applications of exosomes in regenerative medicine.
A number of cell-based services provided by ZenBio comprise human pre-adipocytes (adipose-derived adult stem cells) and placental mesenchymal stem cells (MSC), which are branded by their self-renewing and regenerative capability to differentiate into chondrocytes, adipocytes, and osteocytes. “It is fascinating to see how the injected (stem) cells provide favorable in-vivo effects ,even after their disappearance in the recipient, suggesting the involvement of ‘messengers’ or exosomes secreted by the donor cells that are capable of modulating gene function in targeted tissue”, explains Dr. Ludlow. He further adds, “My role has been leaning more towards providing proof-of-concept for companies that are currently going through IND process for clinical trials and facilitate GMP level process development”. EVs are nanometric entities, carrying microRNAs, bioactive proteins and lipids, requiring extremely precise and sensitive techniques for its isolation and characterization<super-script>2<super-script>. “The qNanoTM was one of the first analytical devices we bought for EV research because of its direct measurement aspect. Clients specifically like the simplicity of the printed results”, exclaims Dr. Ludlow. Joining the conversation, Dr. Clifton Ray, Senior Scientist, ZenBio, states, “We’re using all types of SEC (Size Exclusion Chromatography) columns to isolate EVs from conditioned cell culture media and biofluids, and this is a great method to obtain uncontaminated samples that can be further evaluated for size and concentration using the qNanoTM”. ZenBio is currently investigating the use of smart SEC columns and the Automated Fraction Collector (AFC), a powerful analytical tool providing a standardized, reproducible and robust means of removing extraneous proteins from complex conditioned media samples for cGMP compliant clinical studies. Dr. Ludlow and Dr. Ray agree that in conjunction with contemporary concentration techniques like Tangential Flow Filtration (TFF), high quality and biophysically intact exosomes can be obtained with appropriate surface markers (CD9, CD63, and CD81).
With its ever-expanding product portfolio and technologies to accelerate exosome research, ZenBio is presently working on ‘tuned’ exosomes for applications in regenerative medicine. “Exosomes collected from heat-shocked cells performed better with respect to down regulation of inflammatory cytokines”, explains Dr. Ludlow. He further says, “Adding Platelet-derived Growth Factor (PDGF) to bioreactor media produces exosomes that can help with tendon damage in tendinopathy”. After their positive experience with Izon’s qEV-AFC portal and analyzing more than 600 samples using qNanoTM platform, ZenBio is now engaging with clinical implications of EVs from other biomatrices like urine, CSF, saliva and tear fluid for several applications.
1. Fuster-Matanzo, A., Gessler, F., Leonardi, T., Iraci, N. & Pluchino, S. Acellular approaches for regenerative medicine: on the verge of clinical trials with extracellular membrane vesicles? Stem Cell Res. Ther. 6, 227 (2015).
2. Witwer, K. W. et al. Standardization of sample collection, isolation and analysis methods in extracellular vesicle research. J. Extracell. Vesicles 2, 20360 (2013).