• RoosterBio presents seven posters across ISEV 2026 (San Juan), ISCT 2026 (Dublin), and ISSCR 2026 (Montréal), covering scalable MSC-EV upstream production, GMP-compatible downstream processing, and orthogonal potency analytics including CD73 characterization.
• New this year: RoosterBio’s first public data on iPSC bioprocess development and iPSC-derived MSC (iMSC) manufacturing, presented at ISCT and ISSCR alongside a Repligen collaboration on tangential flow depth filtration for EV purification.
• Key advances on display include the RoosterHD™-EV fed-batch bioreactor medium, Agent V™-DSP for ten-fold improvement in MSC-EV DSP yield, and a QbD-driven iPSC expansion platform enabling weekend-free, GMP-compatible cell banking.

Title	Authors / Presenters	Conference (Abstract #)
Posters
A Fed-Batch Chemically Defined hMSC-EV Bioprocess Medium Enabling 2-4x EV Yield Improvements in Bioreactor Culture	Terri Willstaedt, Amy Walde, Madeline Cramer, Ph.D., Stephen Lenzini, Ph.D., Elie Zakhem, Ph.D., Jon A. Rowley, Ph.D.	ISEV (#374), ISCT (#339)
Advanced Analytical Profiling of MSC-EVs Highlights Tissue- and Donor-Dependent Heterogeneity	Madeline Cramer, Ph.D., Stephen Lenzini, Ph.D., Elie Zakhem, Ph.D., Jon A. Rowley, Ph.D.	ISEV (#380)
Orthogonal Quantification of CD73 Content and Function Across a Scalable MSC-EV Manufacturing Process	Stephen Lenzini, Ph.D., Madeline Cramer, Ph.D., Elie Zakhem, Ph.D., Jon A. Rowley, Ph.D.	ISEV (#146)
A GMP-Compatible Reagent Enables Ten-Fold Improvement in MSC-EV Recovery During Scalable Downstream Processing	Ramon Castellanos-Sanchez, Ph.D., Stephen Lenzini, Ph.D., Jae Jung, Madeline Cramer, Ph.D., Elie Zakhem, Ph.D., Jon A. Rowley, Ph.D.	ISEV (#155)
Engineering Industrialized iPSC Feed Streams via Critical Process Parameter and Raw Materials Optimization	Mary Doolin, Ph.D., Benjamin Burke, Maja Preradovic, Casey Barber, Ph.D., Jon Rowley, Ph.D.	ISCT (#1532), ISSCR (TBD)
iPSC-Derived MSCs Demonstrate Comparable Expansion, EV Production, Surface Marker Expression, and Immunomodulatory Potential to Primary MSCs	Casey Barber, Ph.D., Mary Doolin, Ph.D., Terri Willstaedt, Lauryl Scott, Jon Rowley, Ph.D.	ISCT (#162), ISSCR (TBD)
Scalable Manufacturing of Lentiviral Vectors and MSC-Derived Extracellular Vesicles Using Tangential Flow Depth Filtration	Rachel Legmann1 Keen Chung1, Matthew Rehmann2, Cameron Garland2, Evan Schlaich3 Lauren Tapiero1 Jae Jung2 1 Repligen Corp.; 2 RoosterBio, Inc.; 3 SK Pharmtech	ISCT (#941)
Booths
RoosterBio Booth #1605	ISCT
RoosterBio Booth #1207	ISSCR

A New Portfolio of Call

Spring 2026 winds fill RoosterBio’s sails for journeys to San Juan (ISEV) and Dublin (ISCT), followed by Montréal (ISSCR) in July. We carry with us goodwill, curiosity, and an expanded scientific portfolio to three conferences and both hemispheres. Regulars at past RoosterBio-attended conferences will recognize the theme with our EVs/exosomes from mesenchymal stem/stromal cells (MSC-EVs). [1, 2, 3, 4, 5] That is, we report stirring advances in bioreactor-scalable upstream production, downstream purification, and potency analytics of these therapeutically compelling particles. Yet this year also embarks RoosterBio on a new passage entirely. We now report induced pluripotent stem cell bioprocess media development and iPSC-derived MSCs, comprising key entire new research paths for us to navigate.

ISEV-2026 opens the season in San Juan, Puerto Rico (April 22–26), where four posters push the EV bioprocess and analytics story forward with new quantitative precision. In May, RoosterBio moves to Dublin for ISCT-2026 (May 6–9), where the iPSC work makes its debut alongside continued EV content and the ongoing collaboration with Repligen. The run closes at ISSCR-2026 in Montréal (July 8–11), where our dual iPSC posters might find their most avid audience. For a company that first cut its teeth on optimized MSC manufacturing scale-up for the clinic, this tour reinforces a logical progression into broader solutions for cell engineering of MSCs, primary fibroblasts, EVs, and now iPSCS.

Four Posters Under Caribbean Sun

ISEV-2026 marks the first time the annual EV meeting comes to the Caribbean, hosted at the Puerto Rico Convention Center in San Juan (April 22–26; Education Day on the 22nd). The local organizing committee is anchored by researchers from the University of Puerto Rico campuses and Ponce Health Sciences University. ¡Wepa!

By now, it should be long obvious that the EV community’s reach extends well beyond AsiaPAC, European, and Continental USA research centers. [6] RoosterBio will be presenting across both main poster sessions, with all four posters tied directly to MSC-EV manufacturing and characterization platforms.

A Fed-Batch Chemically Defined hMSC-EV Bioprocess Medium Enabling 2-4x EV Yield Improvements in Bioreactor Culture (Poster #374, April 25)

Most existing hMSC-EV bioreactor workflows require cell expansion in one medium, a wash, and a full medium exchange before EV collection can begin. RoosterHD™-EV replaces this sequence with a single chemically defined fed-batch medium covering both phases. The result is a 2–4x increase in particle yield over traditional processes, validated across bone marrow and umbilical cord donors. EV quality attributes including size distribution, tetraspanin expression, CD73 activity, RNA, and lipid content are preserved. Scale-up in a 3L stirred-tank bioreactor confirmed robustness at production-relevant volumes, with meaningful reductions in media consumption and cost per billion EVs.

Advanced Analytical Profiling of MSC-EVs Highlights Tissue- and Donor-Dependent Heterogeneity (Poster #380, April 25)

Tissue source and donor identity are critical variables in MSC-EV manufacturing, and this poster quantifies both. Using a standardized media system across bone marrow, umbilical cord (UC), and adipose-derived MSCs, and across stirred-tank, vertical wheel, spinner flask, and 2D platforms, the team assembled a comprehensive quality attribute dataset. Three-dimensional bioreactor culture outperformed 2D by approximately 4–5-fold across all platforms. Bone marrow and umbilical cord MSCs yielded higher particle concentrations than adipose, and particle size varied by source (UC-derived particles being the largest with a median of 173 nm and adipose-derived particles being the smallest with a median of 143 nm). Immunomodulatory potency was also tissue-dependent, with BM-MSC EVs driving roughly 85% nitric oxide suppression in LPS-stimulated macrophages versus approximately 45% for umbilical cord and adipose. Within tissue sources, donor identity influenced both yield and CD73 activity, reinforcing the need for systematic donor screening in process development.

Orthogonal Quantification of CD73 Content and Function Across a Scalable MSC-EV Manufacturing Process (Poster #146, April 23)

CD73 is a surface ectonucleotidase that converts AMP to adenosine and may represent a key immunomodulatory potency marker for MSC-EVs. [7] This poster asks whether CD73 content and activity track together across downstream processing (DSP), and whether DSP compromises either. Three independent methods were used: quantitative capillary western blot, an AMP-to-adenosine enzymatic activity assay, and single-vesicle nanoflow cytometry with ERF-calibrated fluorescence. The 0.45 µm clarification filter emerged as the critical step, selectively removing larger particles enriched in CD73 and dropping average molecules per particle from 12.85 at harvest to 5.90 post-filter. Both content and activity remained stable through TFF and sterile filtration. All three assays showed strong mutual agreement (Pearson r > 0.75), establishing a clear correlation between EV content and function, and supporting CD73 content and activity as CQAs suitable for process monitoring and regulatory submissions.

A GMP-Compatible Reagent Enables Ten-Fold Improvement in MSC-EV Recovery During Scalable Downstream Processing (Poster #155, April 23)

Without intervention, cumulative MSC-EV recovery after clarification, TFF, and chromatography typically falls below 5%. This is driven by filter fouling and pressure buildup during the initial clarification step. Agent V™-DSP is a GMP-compatible reagent applied to bioreactor-harvested conditioned medium before DSP begins. Optimal treatment is 1X concentration for 30 minutes, and can be effective across a wide temperature range from room temperature to 37°C. At these conditions, Agent V reduces filter pressure buildup and increases cumulative yield from approximately 5% to approximately 50%. Particle size, EV identity markers (CD63, CD9, CD81), and CD73 enzymatic activity are preserved throughout. Performance was confirmed using conditioned medium generated from a microcarrier-based bioreactor culture.

New Science Flows Through Dublin

Dublin’s River Liffey runs straight through the city center and gives its name to Liffey Hall, the main session venue at ISCT-2026 (May 6–9). Accordingly, this conference inspires cell and gene therapies (GCTs) to flow unidirectionally: from discovery to clinic (with minimal hassle, yet maximum safety & efficacy). RoosterBio brings four posters to Dublin, and for the first time, two of them are about iPSCs. James Joyce’s Dubliners ends with an epic snowfall covering all of Ireland, the living and the dead alike. Yet what arrives in May falls on ground that is very much alive, thriving, and greening! [8]

The aforementioned RoosterHD-EV poster (see ISEV summary above) continues its conference run, presented for the ISCT audience by Terri Willstaedt and colleagues.

Scalable Manufacturing of Lentiviral Vectors and MSC-Derived Extracellular Vesicles Using Tangential Flow Depth Filtration (Poster # and date, TBD)

This collaboration between RoosterBio and Repligen evaluates a single tangential flow depth filtration (TFDF) platform for structurally distinct biologic products including MSC-derived EVs. For EV clarification, a 30 cm² KTFDF module achieved 81% EV recovery from a 50L microcarrier-based bioreactor, comparable to centrifugation, with process times under 2.5 hours and linear scale-up confirmed at 750 cm². EV identity and potency were preserved across the process, as confirmed by tetraspanin marker expression and in vitro wound closure assay. The shared platform reduces process complexity and manufacturing risk across two modalities that are increasingly developed in parallel by CGT sponsors.

The two iPSC posters are also new (below):

Engineering Industrialized iPSC Feed Streams via Critical Process Parameter and Raw Materials Optimization (Poster #1532 , date, TBD)

Clinical and commercial iPSC programs need an upstream process that is not just functional but schedulable, capable of delivering consistent, high-yield lots without weekend interventions. This poster describes a quality-by-design (QbD)-driven, end-to-end iPSC expansion bioprocess built around GMP-compatible critical raw materials and systematically optimized critical process parameters (CPPs). Passage duration proved to be asensitive CPP. iPSCs maintained stable population doubling time on 3-day or alternating 3/4-day schedules, while repeated 4-day passages caused progressive population doubling time (PDT) increase. Media exchange every two days outperformed daily exchange, though extended intervals required increased media volume to compensate for media acidification. TrypLE contact time mattered as well: dissociation beyond 30 minutes reduced cell yield in the subsequent passage. iPSCs expanded through the optimized process consistently maintained pluripotency markers (OCT3/4, TRA-1-60, SSEA4 in >95% of cells across five lines), trilineage differentiation potential, genomic stability, and hematopoietic progenitor differentiation capacity (CD34+CD43+CD45+). This simplified bioprocess enables a single 1-million-cell working cell bank vial to yield 10 billion iPSCs within two weeks, reducing cost and accelerating development.

iPSC-Derived MSCs Demonstrate Comparable Expansion, EV Production, Surface Marker Expression, and Immunomodulatory Potential to Primary MSCs (Poster #162 and date, TBD)

Can iPSC-derived MSCs (iMSCs) perform comparably to primary MSCs within the same bioprocess systems, and do they offer manufacturing advantages that justify the derivation step?

This poster connects RoosterBio’s iPSC platform directly to its established MSC and MSC-EV manufacturing infrastructure. The practical question is whether iMSCs perform comparably to primary MSCs within the same bioprocess systems, and whether the derivation step confers manufacturing advantages worth the effort. iPSCs were directed through mesodermal induction and stabilized via serial passaging in RoosterNourish MSC expansion medium. A pure MSC phenotype was achieved by passage 2–3. iMSCs maintained a doubling time of 20–25 hours through at least 21 population doubling levels, well past the point where primary MSC lines begin to slow significantly, which reached doubling times of approximately 70 hours by PDL 20. Furthermore, iMSCs plugged directly into RoosterBio’s 3D bioprocess for EV production. Canonical positive MSC markers (CD73, CD90, CD105, CD166) were maintained across passages 4–7, with negative markers (CD14, CD34, CD45) consistently absent. Immunomodulatory capacity was confirmed via inducible IDO expression and angiogenic cytokine secretion. EV production and full immunomodulatory profiling are in preparation and will be presented at the conference. Production from a single renewable donor eliminates the multi-donor qualification burden that constrains primary MSC programs, and the extended replicative lifespan substantially reduces starting material requirements per lot.

The iPSC Homecoming in Montréal

If ISCT is the debut for RoosterBio’s iPSC work, ISSCR in Montréal (July 8–11) is where it could find its deepest opportunity for dialog with experts and potential partners. The iPSC community within ISSCR is large, technically sophisticated, and increasingly focused on industrialization, exactly what these posters address. Montréal, a city with deep roots in both French and English-language biomedical research through McGill, Université de Montréal, and the IRCM, is a fitting venue for science that bridges pluripotency biology and manufacturing process development. [9, 10] As Leonard Cohen, Montréal’s most celebrated bard, once observed: there is a crack in everything; that’s how the light gets in. For iPSC science finding its way into RoosterBio’s portfolio, the crack is now open.

Both iPSC posters travel to ISSCR: the iPSC CPP optimization poster (presented by Mary Doolin) and the iMSC comparability poster (presented by Casey Barber). The ISSCR audience overlaps minimally with ISCT, making Montréal an independent exposure to a distinct community of researchers, developers, and potential partners working at the intersection of pluripotent cell biology and advanced therapy manufacturing.

Come See Us

RoosterBio will be exhibiting at  ISCT (Booth #1605) and ISSCR (Booth #1207). If you are attending any of these three conferences, we eagerly welcome the conversation — whether your focus is EV manufacturing, MSC bioprocess scale-up, or the emerging frontier of iPSC-derived starting materials. The scientific portfolio on display, this spring, reflects years of process development work and a deliberate expansion into new territory. We look forward to sharing it, and to hearing what you are building.

RoosterBio is fueling the rapid implementation of scalable advanced therapies. Contact us to discuss how we can accelerate your product and process development. Follow us on LinkedIn for more educational resources.

 

References

1. RoosterBio. RoosterBio’s Equinox Reflections from ISEV & ISCT 2025. 2025; Available from: https://www.roosterbio.com/blog/roosterbios-equinox-reflections-from-isev-isct-2025/.
2. RoosterBio. Right Place, Right Time: RoosterBio’s Spring 2025 Conference Gigs Across 3 Continents. 2025; Available from: https://www.roosterbio.com/blog/right-place-right-time-roosterbios-spring-2025-conference-gigs-across-three-continents/.
3. RoosterBio. The New eXosome Files: ISCT 2024 Features 3 Abstracts from RoosterBio on Bioproduction of Extracellular Vesicles. 2024; Available from: https://www.roosterbio.com/blog/the-new-exosome-files-isct-2024-to-feature-3-abstracts-from-roosterbio-on-bioproduction-of-extracellular-vesicles/.
4. RoosterBio. Upstream, Downstream, & In Between: RoosterBio Collaborations Featured at May 2023 Conferences (ISEV, ISCT, & ASGCT). 2023; Available from: https://www.roosterbio.com/blog/upstream-downstream-in-between-roosterbio-collaborations-featured-at-may-2023-conferences-isev-isct-asgct/.
5. RoosterBio. RoosterBio Joins the Action at ISCT, ASGCT, & ISEV in May 2022. 2022; Available from: https://www.roosterbio.com/blog/roosterbio-joins-the-action-at-isct-asgct-isev-in-may-2022/.
6. Rosado-Galindo, H. and M. Domenech, Substrate topographies modulate the secretory activity of human bone marrow mesenchymal stem cells. Stem Cell Res Ther, 2023. 14(1): p. 208. 10.1186/s13287-023-03450-0
7. Cramer, Madeline. CD73: A Team Player Caught in the “AKT” of Wound Healing & Cell Survival via MSC Exosomes? 2024; Available from: https://www.roosterbio.com/blog/cd73-a-team-player-caught-in-the-akt-of-wound-healing-cell-survival-via-msc-exosomes/.
8. Hawthorne, I. J., et al., Human macrophage migration inhibitory factor potentiates mesenchymal stromal cell efficacy in a clinically relevant model of allergic asthma. Mol Ther, 2023. 31(11): p. 3243-3258. 10.1016/j.ymthe.2023.09.013
9. Li, L., et al., o-Vanillin Modulates Cell Phenotype and Extracellular Vesicles of Human Mesenchymal Stem Cells and Intervertebral Disc Cells. Cells, 2022. 11(22). 10.3390/cells11223589
10. Bikorimana, J. P., et al., ARM-X: an adaptable mesenchymal stromal cell-based vaccination platform suitable for solid tumors. Stem Cell Res Ther, 2025. 16(1): p. 369. 10.1186/s13287-025-04465-5