The research team, led by Kamil Wierzchowski and Łukasz Makowski, set out to answer a deceptively simple question: what shear rates do cells actually encounter in a rocking bioreactor, and how do those rates affect cell survival? The answer matters because rocking bioreactors are increasingly used for growing lymphocytes, stem cells, and other fragile cell types that cannot tolerate the impeller-driven turbulence of stirred tanks. Understanding the hydrodynamic microenvironment is essential for anyone attempting to scale up production of cell therapies or biologics in disposable systems.

To characterize the fluid dynamics, the researchers built a two-dimensional Computational Fluid Dynamics model employing the Volume of Fluid method. This approach tracks the interface between the liquid culture medium and the gas headspace inside the culture bag, allowing the simulation to capture the sloshing wave motion that defines rocking bioreactor operation. The model simulated the culture bag under various rocking angles and frequencies, computing velocity fields, mixing behavior, and shear rate distributions throughout the liquid volume. Crucially, the team validated their numerical predictions against experimental mixing time measurements, achieving an absolute mean percentage difference of 29.2 percent. The model demonstrated high predictive accuracy at very low and very high Reynolds numbers, though its performance degraded somewhat at medium Reynolds numbers, a limitation the authors acknowledge openly.

The shear rate findings are striking. Averaged shear rates across the liquid volume remained below 22.5 s⁻¹ under all studied rocking conditions, values that would seem entirely benign for animal cell cultures. But the local maximum shear rates told a very different story. Under intensified rocking, these localized peaks soared past 30,000 s⁻¹, dramatically exceeding the lethal threshold of 1500 s⁻¹ that the team identified for HL-60 lymphocytes. This means that even though the bulk fluid appears gentle, cells passing through narrow microzones near the bag walls, the wave crest, or the gas-liquid interface can be subjected to shear stresses hundreds of times greater than what the average suggests.

To determine exactly where cell death begins, the researchers used a rotational rheometer to expose HL-60 lymphocytes to controlled shear rates. Their experiments revealed a clear dose-response relationship: cell viability begins to decline at shear rates above 1000 s⁻¹, as cell membranes start to rupture. Above 1500 s⁻¹, the team observed total disintegration of cells. The mechanism is mechanical destruction rather than metabolic exhaustion: hydrodynamic stress physically tears apart the lipid bilayer that encloses each cell, releasing intracellular contents into the medium. The researchers confirmed this by measuring the activity of lactate dehydrogenase, an enzyme normally confined inside cells, in the culture supernatant. Elevated LDH activity served as a molecular fingerprint of membrane damage, correlating directly with the shear conditions the cells had experienced.

The consequences for actual cell culture are significant. When the team grew HL-60 lymphocytes in a rocking disposable bioreactor under conditions where local shear rates consistently exceeded lethal thresholds, they observed impaired cell growth and increased release of intracellular enzymes. The problem was particularly acute during intensified rocking, when higher rocking angles and frequencies were used to improve mixing and oxygen transfer. This creates a fundamental trade-off: the very conditions that enhance mixing intensification and mass transfer also generate the hydrodynamic hotspots that kill shear-sensitive cells.

This trade-off is not merely an academic curiosity. Rocking disposable bioreactors are widely used in biopharmaceutical manufacturing for growing mammalian cell lines, producing viral vectors, and expanding cell therapies. As the industry shifts toward personalized medicine and cell-based treatments, the ability to reliably culture fragile lymphocytes in disposable systems becomes increasingly important. HL-60 cells, a human promyelocytic leukemia cell line derived from a patient with acute promyelocytic leukemia, serve as a well-characterized model for lymphocyte-like cells in this context. Their sensitivity to hydrodynamic stress makes them an ideal sentinel for identifying conditions that would harm other shear-sensitive cell types.

The computational framework developed by the Warsaw team provides a valuable tool for navigating this optimization problem. By simulating shear rate distributions under different operating parameters, researchers can identify rocking angles and frequencies that balance mixing efficiency against hydrodynamic stress. The model can also guide bioprocess scale-up, helping engineers predict how changes in bag geometry, liquid volume, and rocking dynamics will affect the shear microenvironment as processes move from laboratory to production scale. Rather than relying on trial-and-error experimentation, the numerical approach allows systematic exploration of the design space before any cells are placed at risk.

The study also highlights the importance of looking beyond averaged hydrodynamic parameters when assessing bioreactor suitability for shear-sensitive cultures. Traditional scale-up criteria often rely on average shear rates or power input per volume, which can mask the localized extremes that actually determine cell fate. The finding that local maximum shear rates can exceed lethal thresholds while averages remain benign suggests that cell damage in rocking bioreactors may be far more common than previously appreciated. For bioprocess engineers, this means that successful application of rocking disposable bioreactors for fragile cell cultures requires a strategic balance between mixing intensification and the mitigation of lethal local shear effects, informed by detailed computational analysis of the true hydrodynamic microenvironment that cells experience.

Subject of Research: Numerical analysis of shear rate in a rocking bioreactor and its impact on HL-60 lymphocytes

Article Title: Numerical analysis of shear rate in a rocking bioreactor and its impact on HL-60 lymphocytes

Article References: Wierzchowski, K., Krzosa, R., Pawlukiewicz, S., Pilarek, M., & Makowski, Ł. (2026). Numerical analysis of shear rate in a rocking bioreactor and its impact on HL-60 lymphocytes. Applied Microbiology and Biotechnology. https://doi.org/10.1007/s00253-026-14076-6

Image Credits: AI Generated

DOI: 10.1007/s00253-026-14076-6

Keywords: Numerical, analysis, shear, rate, rocking, bioreactor, impact, HL-60, lymphocytes, scientific research

The work, published in iScience, addresses one of the most stubborn bottlenecks in the field. Although MSC-derived EVs have shown remarkable regenerative and immunomodulatory effects in preclinical models — including the modulation of ischemic injury after myocardial infarction — clinical translation has been hampered by the absence of standardized, scalable, and regulatory-compliant manufacturing processes. There is no consensus on a single optimal isolation method, and existing techniques involve trade-offs between purity, yield, and preservation of functional activity. The new study tackles this problem head-on by building an integrated, semi-automated workflow that spans the entire production chain, from cell expansion to final product storage.

The platform begins with clinical-grade Wharton’s jelly-derived MSCs from a validated Master Cell Bank, expanded in a single-use 0.5-liter stirred-tank bioreactor on GMP-grade polystyrene microcarriers, using a chemically defined, serum-free medium. This upstream design is significant for two reasons. First, the microcarrier-based bioreactor configuration supports future scale-out, a critical requirement for commercial production. Second, the chemically defined medium eliminates animal-derived components such as fetal bovine serum or human platelet lysate, which dramatically reduces the risk of contamination by exogenous vesicles or adventitious agents and improves batch-to-batch reproducibility — both essential for therapeutic use.

Over seven days of culture, the cells grew from an initial seeding of 1.8 × 10⁷ to an average of 7.1 × 10⁷ cells, an expansion factor of roughly 2.8. Cell viability remained consistently above 70 percent across all batches, and phenotypic analysis confirmed stable expression of MSC markers (CD90, CD105, CD73) with no detectable hematopoietic or endothelial contaminants. One recurring operational challenge was the formation of cell–microcarrier aggregates, which complicated cell enumeration; the researchers compensated by monitoring lactate levels as a surrogate for metabolic activity, and they note that future optimization of detachment conditions and hydrodynamic parameters could further reduce this counting bias.

The conditioned medium harvested from the bioreactor — designated Intermediate Product 1 — was then concentrated using tangential flow filtration (TFF), a technique in which fluid flows parallel to a semi-permeable membrane rather than perpendicular to it. This crossflow design reduces membrane fouling and allows efficient retention of EVs while smaller molecules pass through. The team used a 750-kDa hollow-fiber cartridge, a higher cut-off than many comparable studies, which helps minimize soluble-protein retention and improves downstream purity. Each batch was processed in two consecutive TFF runs with an intermediate cleaning-in-place step, achieving a volumetric concentration factor of about 31 and a protein concentration factor of about 16, with remarkably low variability between batches.

Following concentration, the material was purified by automated size-exclusion chromatography (SEC) on an ÄKTA go system equipped with two HiLoad Superdex 200 columns. SEC separates particles based on size: larger vesicles elute first because they travel the shortest path through the porous matrix, while smaller contaminating proteins are retained longer. The system’s in-line sensors — monitoring UV absorbance, conductivity, pH, and pressure — enabled real-time process control, and a predefined UV threshold of 10 mAU automatically triggered collection of the EV-enriched fraction. This level of automation minimized operator presence in the cleanroom and reduced operator-introduced variability, a notable advance over previous GMP-aligned processes that relied on manual fraction collection.

The final product was then subjected to a rigorous panel of critical quality attributes (CQAs) aligned with both GMP standards and the Minimal Information for Studies of Extracellular Vesicles (MISEV) recommendations. Bead-based flow cytometry confirmed expression of EV-associated tetraspanins (CD9, CD63, CD81) and MSC markers (CD90, CD105, HLA-ABC), while non-specific markers remained undetectable. Nanoparticle tracking analysis revealed a mean particle concentration of 2.01 × 10¹⁰ particles per milliliter and a median size of 146.2 nanometers. Cryogenic transmission electron microscopy confirmed intact, bilayer-enclosed vesicles with minimal non-vesicular background. Protein and lipid concentrations, along with their ratios to particle number, remained stable across all four manufacturing batches.

Crucially, the researchers also demonstrated functional potency. CD73 enzymatic activity — which catalyzes the conversion of the proinflammatory molecule AMP into anti-inflammatory adenosine — was robustly detected and abolished by a specific inhibitor, confirming that the vesicles carry a defined immunomodulatory mechanism. In parallel, the EVs inhibited the proliferation of stimulated T cells from healthy donors by an average of about 18 percent, though without a consistent dose-response pattern. The authors are careful to note that these two assays interrogate distinct aspects of EV bioactivity and should not be expected to correlate directly; they propose CD73 activity as a promising candidate for routine batch release, while positioning the T cell assay as a complementary, higher-order biological readout.

Stability testing over 12 months of storage at −80°C in PlasmaLyte 148 — an excipient-free, parenteral-grade electrolyte solution — showed that protein concentrations, particle size, particle concentration, and CD73 activity were largely preserved. The authors emphasize that this one-year window represents the maximum duration experimentally validated to date, not a definitive expiry date, and that dedicated post-thaw in-use stability studies will be required before clinical administration. For now, they have adopted a conservative maximum post-thaw holding time of two hours.

The platform’s design is deliberately transposable. The three core unit operations — bioreactor-based cell expansion, tangential flow filtration, and size-exclusion chromatography — are individually well-established in regulated biomanufacturing environments, which may facilitate regulatory acceptance. Switching to a different MSC source or cell line would require re-tuning of upstream and downstream critical process parameters and re-definition of quality attributes, but the overall architecture can be retained. The authors acknowledge that their evaluation was limited to four manufacturing batches from two donors, and that formal cleaning validation under worst-case conditions remains necessary. Nevertheless, the demonstrated process control, product consistency, and frozen stability provide a robust foundation for advancing MSC-EV-based therapeutics from the laboratory bench toward the clinic — a milestone that could reshape how regenerative medicines are manufactured and delivered in the years ahead.

Subject of Research: GMP-compliant manufacturing and validation of extracellular vesicles from mesenchymal stromal cells

Article Title: Design and validation of a GMP-compliant manufacturing platform of extracellular vesicles from mesenchymal stromal cells

Article References: Courageux, Y., Monguió-Tortajada, M., López-Fernández, A., Schoch, L., Poblador, F., Morini, S., Prat-Vidal, C., Rodriguez, L., Torrents, S., Aran, G., Codinach, M., Gálvez-Montón, C., Bayes-Genis, A., Vives, J., Querol, S., & Roura, S. (2026). Design and validation of a GMP-compliant manufacturing platform of extracellular vesicles from mesenchymal stromal cells. iScience, 29(11), Article 117881. https://doi.org/10.1016/j.isci.2026.117881

Image Credits: AI Generated

DOI: 10.1016/j.isci.2026.117881

Keywords: extracellular vesicles, mesenchymal stromal cells, GMP manufacturing, Wharton's jelly, tangential flow filtration, size-exclusion chromatography, regenerative medicine, advanced therapy medicinal products, immunomodulation, CD73, bioreactor, clinical translation

Wild mountain ginseng, Panax ginseng Meyer, occupies a near-mythical status across Korea, China, and Japan, where it has been harvested for centuries as a medicinal herb and health food. Its value stems from ginsenosides, a family of triterpene saponins that constitute the plant’s primary pharmacological constituents. These compounds are conventionally divided into three structural groups: the protopanaxadiol type, which includes well-studied molecules such as Rb1, Rb2, Rb3, Rd, Rg3, and Rh2; the protopanaxatriol type, encompassing Re, Rf, Rg1, Rg2, and Rh1; and the oleanolic acid type, represented by Ro and related saponins. Decades of research have attributed a remarkable spectrum of biological activities to ginsenosides, including immune enhancement, antioxidant and antibacterial effects, antidiabetic and anti-inflammatory actions, anti-aging properties, and cardioprotective and neuroprotective benefits.

The problem, of course, is supply. A wild mountain ginseng root of this age is an extraordinarily rare resource, and demand for authentic, high-quality material far exceeds what nature can provide. The research team’s strategy was to sidestep the bottleneck entirely by generating adventitious roots, roots that arise from somatic tissue rather than from seed germination, from the 150-year-old specimen, designated 150y-Mg. These cultured roots were then scaled up in 1000-liter industrial bioreactors, where they grew in Murashige and Skoog medium supplemented with 5 percent sucrose by weight and 5 milligrams per liter of indole-3-butyric acid, a synthetic auxin that promotes root growth and ginsenoside accumulation.

The central question was whether the cultured roots could genuinely be considered the same plant. To answer it, the researchers turned to SNP genotyping, a technique that reads single-nucleotide variations scattered across the genome and produces a molecular fingerprint unique to each individual. Using a panel of 192 SNP markers, they compared the original mountain ginseng with two independently analyzed adventitious root samples. The result was unambiguous: 100 percent genotype concordance across the entire panel. Of the 192 loci, 184 were homozygous, meaning both copies of the gene carried the same variant, five were heterozygous, and three produced null calls that could not be scored. Calculated across the 189 callable non-null loci, the genetic fixation rate stood at 97.4 percent, a figure that reflects the high homozygosity typical of a long-lived, likely self-purging lineage rather than any discrepancy between the parent plant and its cultured offspring.

With genetic identity confirmed, the team shifted to the metabolome, the complete inventory of small molecules that defines what a plant actually produces. Liquid chromatography coupled with mass spectrometry, or LC–MS, revealed clear chemical differences among the analyzed materials. Within the sample set examined, malonyl ginsenoside Rb2/Rb3 was detected in the original 150-year-old mountain ginseng but not in cultivated Panax ginseng, whereas ginsenosides XVII and F2 appeared in the bioreactor-grown adventitious roots but were absent from cultivated ginseng under the same analytical conditions. The authors are careful to frame these observations as comparison-specific metabolite features rather than validated authentication markers, a distinction that matters for any future attempt to certify the origin of ginseng products in the marketplace.

That caution is scientifically warranted. A single comparison between one wild specimen and one cultivated reference cannot establish whether a particular metabolite is truly characteristic of age, habitat, or lineage. Environmental conditions, developmental stage, and analytical parameters can all shift the metabolic profile of ginseng tissue. What the LC–MS data do provide is a shortlist of candidate compounds, malonyl ginsenoside Rb2/Rb3, ginsenoside XVII, and ginsenoside F2, that now deserve systematic validation across broader and independent ginseng cohorts before they could ever serve as reliable markers of wild mountain provenance.

Complementing the LC–MS work, high-performance liquid chromatography, or HPLC, quantified the ginsenoside content of the adventitious roots and revealed distinct quantitative patterns that set them apart from conventional material. The relative proportions of individual saponins matter enormously for pharmacological activity, since different ginsenosides act on different molecular targets in the human body. A culture line that skews toward particular saponin classes could, with further optimization, become a standardized source of specific bioactive molecules, something that wild-harvested roots, with their inherent variability, can never guarantee.

The biomedical potential of the bioreactor-grown roots was explored through preliminary in vitro assays. These experiments provided early evidence of two activities of considerable commercial and clinical interest: anti-inflammatory effects and the ability to stimulate the proliferation of dermal papilla cells, the specialized fibroblasts at the base of hair follicles that regulate hair growth. The dermal papilla finding in particular hints at possible applications in cosmetics and hair-loss research, an area where ginseng-derived compounds have long attracted attention. The authors emphasize, however, that these are preliminary results, and the path from a cell-culture assay to a validated therapeutic or cosmetic ingredient involves extensive further testing.

What makes this study notable is not any single result but the complete pipeline it demonstrates. A rare, irreplaceable botanical resource was captured genetically, propagated indefinitely in sterile culture, scaled to industrial volumes, verified as a true genetic match, and profiled chemically and functionally, all without the plant ever leaving the laboratory. The 1000-liter bioreactor scale is the crucial detail here: it transforms what would otherwise be a botanical curiosity into a feasible production platform. Adventitious root culture of ginseng has been explored before, but anchoring the technology to a documented 150-year-old wild genotype, with SNP-level traceability, raises the standard for authenticity in an industry plagued by adulteration and mislabeling.

The researchers are candid about the limits of the current work. The metabolite features they observed are candidates, not conclusions, and the in vitro activities require confirmation in more rigorous models. Yet the foundation they have laid, complete genetic concordance, a reproducible culture system, and a defined chemical baseline, gives the field exactly what it needs to move forward: a stable reference material against which future wild and cultivated ginseng samples can be compared. If subsequent studies validate the candidate markers across independent cohorts, the combination of SNP fingerprinting and LC–MS profiling could become a powerful authentication toolkit. And if the anti-inflammatory and dermal papilla activities hold up, the roots of a plant that took 150 years to grow in the mountains may one day be produced by the ton, its ancient chemistry preserved in stainless steel tanks rather than in vanishing forest soil.

Subject of Research: Metabolomic profiling and bioreactor production of adventitious roots from a 150-year-old wild mountain ginseng

Article Title: Metabolomic profiling and biomedical potential of adventitious roots derived from a 150-year-old mountain ginseng

Article References: Lee, H.-S., Han, J.-E., Kwon, A.-R., Son, E.-J., Park, H., Kim, M.-O., Kim, Y. J., Lee, K. Y., Yang, T.-J., Murthy, H. N., Paek, K.-Y., & Park, S.-Y. (2026). Metabolomic profiling and biomedical potential of adventitious roots derived from a 150-year-old mountain ginseng. BMC Plant Biology. https://doi.org/10.1186/s12870-026-10136-1

Image Credits: AI Generated

DOI: 10.1186/s12870-026-10136-1

Keywords: Panax ginseng, mountain ginseng, ginsenosides, adventitious roots, metabolomics, LC-MS, SNP genotyping, plant biotechnology, bioreactor, anti-inflammatory, dermal papilla cells, BMC Plant Biology

The study, published in Bioengineering & Translational Medicine, comes from researchers at The University of Alabama who set out to strip away the confounding ingredients that have long plagued organoid modeling. Conventional glioblastoma organoids are typically made by embedding glioblastoma stem cells in animal-derived matrix hydrogels such as Matrigel and differentiating them with undefined serum supplements. Those ingredients provide structure, but they also mask the cells’ intrinsic capacity to fabricate their own microenvironment, introduce batch-to-batch variability, and make it nearly impossible to know whether any vessel-like structure observed in a dish formed because of the model or in spite of it. The new approach removes the exogenous matrix entirely, relying instead on controlled geometry and a sublethal level of fluid shear stress to coax the cells into organizing themselves.

To judge whether the resulting organoids were biologically faithful, the team first needed a rigorous clinical benchmark. They mined publicly available transcriptomic data from The Cancer Genome Atlas, curating a high-confidence subset of 35 patient cases spanning healthy brain tissue, low-grade glioma, and glioblastoma. Because the World Health Organization reclassified central nervous system tumors in 2021, shifting diagnosis toward molecular definitions, many older low-grade glioma cases would today be called glioblastoma. The researchers therefore subdivided the low-grade glioma cohort into molecular subgroups—those resembling normal tissue, those resembling glioblastoma, and a transitional group—effectively modernizing the clinical baseline. Principal component analysis revealed a clear developmental axis, and differential expression analysis defined a conserved glioma signature: upregulation of embryonic-like tissue growth programs and oxidative phosphorylation, paired with suppression of mature neuronal pathways, particularly GABA-ergic signaling. Crucially, network analysis identified VEGFA and fibronectin as central hubs linking vasculogenesis to collagen metabolism, confirming that glioma progression is underpinned by coordinated remodeling of neurovascular and matrix components.

With that baseline in hand, the team grew organoids from a patient-derived xenograft line called JX6, a classical-subtype glioblastoma carrying the amplified EGFR variant III mutation. Glioblastoma stem cells were first seeded into cell-repellent U-bottom plates to form spheroids of roughly 400 to 600 micrometers, then transferred to a stirred 100-milliliter bioreactor operating at a shear stress of about 0.5 pascals. No other media components, matrices, or scaffolds were added at any point. Under these conditions the organoids grew to four millimeters in diameter, and the researchers tracked their molecular development against the patient data across a unified five-stage scale. The comparison revealed a striking convergence: trajectories for capillary, venule, and large artery gene markers, along with astrocyte, fibroblast, and pericyte/smooth muscle cell signatures, all peaked in alignment with clinical benchmarks at the two-millimeter stage of organoid growth.

That two-millimeter milestone emerged as the heart of the study. Confocal imaging of organoids stained for the endothelial marker CD31 and the matrix proteins tenascin-C and fibronectin revealed a precise temporal cascade. Tiny 0.6-millimeter spheroids expressed essentially none of these markers. By one millimeter, tenascin-C—an anti-adhesive matrix protein associated with cell migration—appeared around the organoid core. At 1.5 millimeters, fibronectin was deposited peripherally and nascent endothelial clusters emerged. Only at two millimeters did fibronectin and CD31 significantly co-localize, indicating that the tumor cells first fabricate a fibronectin-rich scaffold and then recruit endothelial cells onto it—a matrix-primed sequence of vascular assembly that has been described in glioblastoma patients but rarely recapitulated in vitro.

The spatial architecture of the mature organoids proved equally faithful. Two-millimeter organoids displayed a distinct tri-zonal organization: an infiltrating rim rich in tenascin-C, a vascular-like area dominated by fibronectin and CD31, and a hypoxic, necrotic core. The rim’s thickness of roughly 153 to 180 micrometers sits just below the approximately 200-micrometer oxygen diffusion limit, defining a structurally coherent metabolic boundary. The vascular-like zone, spanning about 750 to 1,013 micrometers, contained the densest vessel branching and the tightest lumen spacing, echoing the weblike capillary beds of living tissue. Quantifying lumen sizes by minimum Feret diameter showed that most channels fell in the 5-to-10-micrometer range—the expected caliber of human capillaries—with larger structures matching arteriole and venule dimensions, and none exceeding 105 micrometers.

To test whether these structures were more than anatomical decoration, the researchers incubated organoids with a 3-kilodalton fluorescent dextran tracer, chosen because its size approximates temozolomide, the standard chemotherapy for glioblastoma. Multiphoton imaging of whole-mount cleared organoids showed clear tracer transport within capillary-like lumens of 9 to 12 micrometers in diameter, and the radial intensity gradients fit Fick’s second law of diffusion modeled in spherical coordinates, yielding an effective diffusion coefficient of about 0.15 square micrometers per second. That value is more than two orders of magnitude lower than measurements of 3-kilodalton dextran diffusion in the rat brain extracellular space, likely reflecting the densely packed protective rim, immature endothelial junctions, and the absence of internal hemodynamic shear stress. The authors note that human glioma tissue itself poses elevated diffusion resistance due to increased extracellular volume and tortuosity linked to tenascin-rich matrix deposition, so the comparison, while sobering, is not entirely discouraging.

The divergences that remain are informative rather than fatal. Organoids underexpressed proteoglycans involved in cell-matrix adhesion and diverged on arterial and large-vein markers, patterns the researchers attribute to the lack of controlled hemodynamic shear stress—the tangential force from blood flow that stabilizes endothelial identity in living vessels. Their proposed remedy is elegant: introduce internal perfusion via microfluidics at the one-to-1.5-millimeter stage, after the critical tenascin-C and fibronectin matrix has self-organized but before endothelial networks fully mature, while maintaining the existing bulk shear of roughly 0.5 pascals to support peripheral expansion. Such a system could push the organoids from modeling the anatomy of the tumor microenvironment toward a genuinely functional, human-centric platform for preclinical drug validation.

The therapeutic implications may be the most exciting part. Because the model reveals that glioblastoma stem cells actively prime their niche with an anti-adhesive-to-adhesive matrix switch—tenascin-C first, fibronectin second—to enable invasion and neovascularization, it nominates that scaffold as a drug target. High-throughput screening using these organoids could identify small molecules or antibodies that disrupt tenascin-C and fibronectin assembly, potentially weakening the tumor’s structural defenses and improving drug penetration across the blood-brain barrier. For a disease where nearly every experimental therapy has foundered on the same two obstacles—infiltration at the tumor margin and delivery across the vasculature—a reproducible, scaffold-free, human-derived model that recapitulates both processes autonomously represents a meaningful step forward. The organoids do not yet beat like a living brain, but they are, remarkably, building themselves.

Subject of Research: Matrix-free biomanufacturing of glioblastoma organoids that self-assemble neurovascular-like structures and extracellular matrix

Article Title: Exogenous matrix‐free biomanufacturing of glioblastoma organoids enables autonomous assembly of neurovascular‐like structures and extracellular matrix

Article References: Avera, A. D., Schnorbus, T. N., & Kim, Y. (2026). Exogenous matrix‐free biomanufacturing of glioblastoma organoids enables autonomous assembly of neurovascular‐like structures and extracellular matrix. Bioengineering & Translational Medicine, Article e70166. https://doi.org/10.1002/btm2.70166

Image Credits: AI Generated

DOI: 10.1002/btm2.70166

Keywords: glioblastoma, organoids, neurovascular unit, extracellular matrix, glioblastoma stem cells, tenascin-C, fibronectin, biomanufacturing, blood-brain barrier, drug screening, TCGA, bioreactor

The team, drawn from the Colorado School of Mines and the California-based company Mango Materials, tested a hollow fiber membrane contactor, a device in which thousands of thin polypropylene tubes act as selective barriers. Liquid water flows through the inside of the fibers while gas flows around them, and because the hydrophobic membrane repels liquid water but lets gas molecules pass, oxygen can dissolve into the liquid without a single bubble ever forming. Unlike sparging, the interfacial area of such a membrane is fixed and independent of flow rates, and the liquid and gas streams can be tuned independently to thin the boundary layers that limit transfer. The driving force is simply the difference in gas concentration, or partial pressure, between the gas and liquid sides, which is why the researchers suspected gravity should play no role at all. Proving it, however, required taking the apparatus somewhere gravity itself could be switched off.

Their motivation goes beyond fundamental fluid physics. Mango Materials has developed a membrane-aerated bioreactor in which methanotrophic bacteria consume methane and oxygen to build biomass and, when nutrients are withheld, the biopolymer poly-3-hydroxybutyrate, or PHB, a versatile plastic used in additive manufacturing, textiles and even food additives. Methane for such a reactor could be harvested from the Sabatier reaction aboard the International Space Station, where it is currently vented as waste, or pulled directly from the Martian atmosphere. Converting that carbon into PHB would be a textbook example of in-situ resource utilization. But before a membrane-aerated bioreactor can fly, engineers must be sure the gas delivery step itself is indifferent to gravity, so that any gravitational effects seen later in a full bioreactor can be confidently attributed to biology rather than plumbing.

Measuring gas transfer in reduced gravity is brutally constrained by time. During a parabolic flight, the aircraft’s steep climbs and dives produce stretches of about 15 to 28 seconds of simulated reduced gravity, far too short for commercial methane sensors, whose response times lag well behind the data window. The team therefore focused on oxygen transfer into an abiotic medium of deionized water held at 37 degrees Celsius, the same temperature as the bacterial cultures the system is meant to serve. They selected a compact 3M Liqui-Cel hollow fiber module with fibers 330 micrometers in outer diameter and pores of 0.1 micrometers, chosen for its high flux, small internal volume and transparent shell that allowed visual monitoring for condensation. Fast optical oxygen sensors with a measured response time of just 0.725 seconds, roughly 27 times faster than the oxygenation process itself, made it possible to resolve the transfer dynamics within each brief window of weightlessness.

The apparatus was a marvel of compact engineering, organized into three interlocking subsystems. A pneumatic loop alternated between pure nitrogen, used to strip dissolved oxygen down to about one percent of saturation, and pure oxygen, delivered at one liter per minute through digitally controlled flow controllers with the line held at 20 PSI. A hydraulic loop pumped 560 milliliters of deionized water through the membrane at five liters per minute, past redundant oxygen sensors, pressure gauges and a hydraulic accumulator that compensated for water lost by evaporation through the membrane. A thermal loop of about four liters of water, heated by a Peltier device and coupled through a shell-and-tube heat exchanger, held the test liquid at 37 degrees with an accuracy of plus or minus one degree, using the thermal mass of the larger volume to suppress fluctuations. Flow-activated switches protected the system from freezing or boiling if circulation ever stopped, a safeguard that would prove prescient.

During the flight, two operators pressed identical buttons at the call of each parabola, a redundancy in case nausea compromised one of them, triggering a seven-second pulse of oxygen through the membrane’s gas side. A triaxial accelerometer mounted near the aircraft’s center of gravity verified that the simulated environments hit their targets: 0.38 g for Martian gravity, 0.16 g for Lunar gravity and under 0.1 g for microgravity, all within 0.1 g of the intended level during the critical measurement window. The team had planned ten parabolas per gravity level, but a dust containment breach from another experiment ended the flight early, and a more insidious problem emerged during the second set of microgravity parabolas. A bubble that had sat stably in the thermal loop under Martian and Lunar gravity drifted free in weightlessness, lodged in a flow switch and silently shut down the temperature control. The researchers discarded the affected cycles, leaving five valid microgravity measurements, and applied a temperature correction to the remaining data.

When the numbers were crunched, the result was as clean as an experimentalist could hope for. Oxygen mass transfer coefficients averaged between 1.11 and 1.16 times ten to the minus four meters per second across all four gravity conditions, a spread so narrow it borders on statistical indistinguishability. Student’s T-tests comparing terrestrial, Martian, Lunar and microgravity datasets produced p-values of 0.41, 0.48 and 0.85, all comfortably above the 0.05 threshold, meaning no significant difference could be detected between any pair of gravity levels. The measured coefficients also landed within 25 percent of a theoretical estimate based on the Sherwood relation for hollow fiber modules and matched values reported in earlier terrestrial studies, lending further confidence to the measurements. The slightly larger scatter seen in the reduced-gravity datasets was traced not to gravity itself but to the vibration and acceleration fluctuations inherent in parabolic flight, which accelerometer data and Fourier analysis confirmed were far quieter during the terrestrial baseline.

The implications ripple outward well beyond bioreactors. Because membrane contactors transfer gas in both directions, they can not only deliver feed gases but also strip waste products from a reaction, and by Le Chatelier’s principle, removing a product can itself accelerate the underlying chemistry. Membrane contactors already maximize biomethane recovery in anaerobic wastewater treatment on Earth, and they are being integrated into electrolyzer electrodes, where gas bubbles that stubbornly cling to surfaces in reduced gravity would otherwise choke off hydrogen and oxygen production. The new result provides a crucial assurance for those designs: if a membrane-enhanced electrolyzer or bioreactor performs differently in space, the credit or blame belongs to the electrochemistry or the microbes, not to the gas delivery hardware. The findings also raise the Technology Readiness Level of membrane gas transfer for space life support, a milestone that agencies weigh heavily when deciding which technologies earn a berth on future missions.

The team is now looking toward the next logical step: a small demonstration membrane-aerated bioreactor designed for long-duration operation aboard the International Space Station, where the biological half of the methane-to-PHB process can finally be tested under sustained weightlessness. In the meantime, the parabolic flight rig itself may prove as valuable as the result it produced. The authors note that the system, capable of completing a full oxygen transfer measurement in under ten seconds through an innovative dual water loop design, could be readily adapted to compare different membrane modules or to measure the transfer rate of any pure gas for which an inline sensor exists, positioning it as a high-throughput characterization tool for next-generation membrane materials. For a field in which every launch opportunity is scarce and every kilogram of hardware is fought over, a technology that works exactly the same on Earth as it does on the Moon, Mars or in the void between them is precisely the kind of boring reliability that space exploration depends on.

Subject of Research: Membrane gas–liquid oxygen mass transfer under variable gravity conditions during parabolic flights

Article Title: Experimental system for investigating membrane gas–liquid mass transfer during a parabolic flight

Article References: Bray, A., Lampe, J., Schwiebert, A. M., Bush, J. A., Jacobs, A., Force, N., Pieja, A., Munakata-Marr, J., & Vanneste, J. (2026). Experimental system for investigating membrane gas–liquid mass transfer during a parabolic flight. Space and Planetary Resources, 2(1), Article 2. https://doi.org/10.1007/s44461-026-00007-w

Image Credits: AI Generated

DOI: 10.1007/s44461-026-00007-w

Keywords: membrane contactor, hollow fiber membrane, gas-liquid mass transfer, parabolic flight, microgravity, Martian gravity, Lunar gravity, oxygen transfer, bioreactor, in-situ resource utilization, space life support, PHB biopolymer

The problem begins with how C. asiatica is currently sourced. Wild harvesting remains the dominant supply model, and the review documents staggering variability: centelloside content in wild populations fluctuates up to five- to ten-fold depending on geography, environment, and harvest timing. Because the plant naturally favors swamp and marsh ecosystems, wild-collected material faces elevated risks of heavy metal contamination, pathogen exposure, and adulteration. Field surveys in Peninsular Malaysia found significant accumulation of cadmium, copper, nickel, lead, and zinc in wild-harvested gotu kola, with estimated daily intakes suggesting potential lead toxicity risk from plants gathered at polluted sites. Standards bodies such as the World Health Organization expect high-quality herb to contain at least two percent triterpene saponins, while the European Scientific Cooperative on Phytotherapy reports saponin and sapogenin content ranging from one to eight percent—a spread that makes quality control a persistent headache for phytopharmaceutical manufacturers.

Cultivation has not solved the problem either. The review highlights a paradox familiar to anyone working with medicinal plants: more biomass does not mean more medicine. Unlike conventional crops where yield predicts output, C. asiatica can produce lush growth while delivering disappointingly dilute metabolite profiles. Multiple factors shape both growth and centelloside accumulation, including cultivation system, propagation method, light regime, genotype, soil type, farming practice, and even the ploidy status of planting material. Researchers exploring aquaponics, co-cultivation with the root endophyte Piriformospora indica, and polyhouse cultivation of rooted cuttings have reported cultivar-specific differences and dynamic metabolite trends, reinforcing the need for extensive genotypic screening before any field program can deliver consistent quality.

This is where plant tissue culture enters the picture. Callus cultures initiated from leaves, petioles, and nodal segments using auxins such as 2,4-dichlorophenoxyacetic acid and naphthaleneacetic acid, often paired with cytokinins like benzylaminopurine, have reliably produced triterpenoid- and flavonoid-rich biomass. Cell suspension cultures and hairy root cultures—induced through transformation with Agrobacterium rhizogenes—have emerged as the most scalable platforms because they grow rapidly in liquid media, remain genetically stable, and do not require exogenous hormones. Notably, Baek and colleagues demonstrated that petiole-derived hairy roots produced 1.4 times more triterpenoids than leaf-derived lines, a reminder that even the choice of starting explant can decisively shape biosynthetic output. In suspension cultures, asiaticoside accumulation peaked at 1.7-fold above baseline between 21 and 25 days of culture.

The heart of the review is a systematic comparison of elicitation strategies, and the numbers are striking. Methyl jasmonate, the field’s workhorse elicitor, increased asiaticoside by 494 percent in cell suspensions, by 5.6- to 71-fold in hairy roots, and by 69-fold in callus, depending on genotype and treatment conditions. Coronatine delivered 116 milligrams per gram dry weight of madecassoside in elicited hairy roots at day 14 post-elicitation—one of the highest absolute yields ever reported. But the authors issue a crucial warning about the so-called fold-increase paradox: a two-fold rise from a 20 milligram per gram baseline yields 40 milligrams per gram, which is pharmaceutically far more relevant than a 50-fold rise from 0.1 milligrams per gram yielding just 5. Tetraploid hairy roots responded more dramatically to methyl jasmonate than diploid lines, likely because their untreated controls were extremely low to begin with. Heavy metal elicitors such as cadmium and lead could drive 24- and 49-fold increases in asiaticoside and madecassoside respectively, but the authors dismiss these as unusable for pharmaceutical production because of phytotoxicity and contamination risk.

Among biotic elicitors, the toolkit is expanding rapidly. Yeast extract delivered a 3.5-fold boost in asiaticoside, chito-oligosaccharide achieved a five-fold increase in hairy roots at 30 parts per million, and pectin raised asiaticoside content by 31 percent in callus cultures. Endophytic symbionts add another layer of sophistication: Piriformospora indica colonization triggered a 2.5-fold increase in asiaticoside through activation of root-associated stress responses, while rhizobacteria such as Azospirillum and Pseudomonas promote triterpenoid biosynthesis by stimulating jasmonic acid and ethylene signaling pathways. Combined elicitor treatments—methyl jasmonate plus salicylic acid, or coronatine plus methyl jasmonate—consistently outperform single agents, suggesting synergistic activation of jasmonate- and salicylate-dependent signaling, though optimal ratios and staged application sequences remain largely untested.

Beyond elicitation, the review maps several emerging enhancement strategies. Precursor feeding with squalene at 2.5 micromolar boosted total triterpenoids 3.1-fold to 57.53 milligrams per gram dry weight, while higher concentrations triggered feedback inhibition—a classic concentration-dependent regulatory signature. Pyruvic acid supplementation increased triterpenoids 1.9-fold with preferential enhancement of madecassoside. Cell permeability enhancement through ultrasound-assisted extraction has proven remarkably effective: optimized conditions yielded 83.14 milligrams per gram of asiatic acid and 19.71 milligrams per gram of asiaticoside, and combining ultrasound with natural deep eutectic solvents pushed asiaticoside recovery to 229.92 milligrams per gram. Reversible electroporation could theoretically enable repeated, non-destructive metabolite harvesting from viable cultures, transforming batch processes into semi-continuous bioreactor-compatible systems—though this remains untested in C. asiatica.

The genomic era is now catching up with the chemistry. A haplotype-resolved genome assembly published in The Crop Journal confirmed that CaCYP716C11 catalyzes the conversion of 23-hydroxyursolic acid to asiatic acid, and identified CaUGT73CL69 as a glucosyltransferase that converts asiatic acid and madecassic acid to their respective monoglucosides. Tandem duplicate clusters of CaUGT73 genes on chromosome 8 reveal that gene duplication and neofunctionalization have shaped the plant’s glycosylation capacity. Earlier transcriptomic work flagged CaHDR1, CaIDI2, and CaβAS1 as key regulators, while UGT73AH1 and the glycosyltransferases CaUGT73C7 and CaUGT73C8 appear to catalyze the rate-limiting steps that assemble the characteristic sugar chains of asiaticoside and madecassoside. Yet the review’s authors caution that transcript abundance establishes correlation rather than causation, and no peer-reviewed study has yet reported CRISPR/Cas9-mediated editing of centelloside biosynthetic genes in this species.

Scale-up remains the field’s stubborn bottleneck. A 5-liter stirred bioreactor achieved 60.08 milligrams per gram dry weight of asiaticoside with optimized agitation and aeration, while a Plantform temporary immersion system combined with methyl jasmonate elicitation delivered centelloside levels 2.8-fold higher than elicited shake flasks—and 12.2-fold higher than untreated controls. A twin-bottle temporary immersion system more than tripled biomass compared to conventional semi-solid culture, though it did not quantify centellosides. Hairy root cultures, despite their biosynthetic promise, resist scale-up because their dense branching architecture and sensitivity to mechanical stress limit mass transfer. The review identifies mist reactors, wave-mixed bioreactors, and low-shear stirred tanks as untested but promising alternatives. On the translational front, preliminary estimates suggest bioreactor production only becomes economically competitive when centelloside yields exceed 5 percent dry weight and process volumes surpass 500 liters—thresholds that current elicited cultures approach but rarely achieve.

Perhaps the most forward-looking suggestion concerns extracellular vesicles. Membrane-bound nanoparticles secreted by C. asiatica cell cultures have recently been characterized and shown to carry high levels of polyphenols, reduce intracellular reactive oxygen species, suppress pro-inflammatory genes such as COX2, and promote skin repair by inhibiting tyrosinase activity and upregulating barrier-related genes including filaggrin and aquaporin-3. These vesicles outperformed conventional cell culture extracts in stability, cellular uptake, and precision. Because centellosides are packaged during vesicle biogenesis from the endomembrane system, elicited suspension cultures may serve as a platform for generating centelloside-enriched vesicles directly—skipping the extraction step entirely. Combined with the review’s proposed research framework, which prioritizes complete pathway elucidation, enzyme characterization, and systems-level regulatory mapping before engineering intervention, the picture that emerges is one of a field standing at an inflection point: the biological machinery is increasingly understood, the culture platforms are proven, and the remaining gaps—functional validation of candidate genes, standardized elicitor dosing, and validated industrial-scale bioprocesses—are now clearly defined targets rather than open questions.

Subject of Research: Centelloside biosynthesis enhancement in tissue cultures of Centella asiatica

Article Title: Advancements on centelloside biosynthesis in tissue cultures of Centella asiatica (L.) Urban

Article References: Hundare, A., & Joshi, N. (2026). Advancements on centelloside biosynthesis in tissue cultures of Centella asiatica (L.) Urban. Discover Plants, 3(1), Article 396. https://doi.org/10.1007/s44372-026-00867-8

Image Credits: AI Generated

DOI: 10.1007/s44372-026-00867-8

Keywords: Centella asiatica, centellosides, asiaticoside, madecassoside, plant tissue culture, hairy root cultures, elicitation, methyl jasmonate, bioreactor, metabolic engineering, CRISPR, extracellular vesicles