Journal: iScience
Article Title: Design and validation of a GMP-compliant manufacturing platform of extracellular vesicles from mesenchymal stromal cells
doi: 10.1016/j.isci.2026.117881
Figure Lengend Snippet: Tangential flow filtration (TFF)-mediated concentration of Intermediate Product 1 (IP1) and associated performance (A) Schematic illustration of the TFF principle, showing a cross-section of a single hollow fiber within the TFF cartridge. Unlike dead-end filtration—where particles accumulate on the membrane surface-TFF employs a crossflow (Feed) that directs fluid parallel to a semi-permeable membrane, selectively retaining extracellular vesicles (EVs), while smaller particles pass through the fiber pores into the permeate, driven by transmembrane pressure (TMP). (B) Schematic representation of the filtration system. IP1 is transferred to the stirred tank reservoir (yellow section) and recirculated in the main loop (orange circuit) under a controlled pressure of 0.9–1.3 bar. Soluble components below the nominal 750-kDa membrane cut-off pass through the semi-permeable membrane, forming the permeate (blue section), enabling gentle and efficient concentration. Upon reaching the minimum retentate volume, it is collected via a three-way stopcock (green section). (C) Filtration performance during TFF across multiple batches, showing the volume of filtered conditioned medium per minute over time for two consecutive runs, with a cleaning step in between (dashed line). The shaded area highlights an initial stabilization phase. Batch 1 filtration-profile values could not be retrieved due to an unexpected software error; the run remained under operator supervision and was retained for downstream validation. (D) Volume reduction during TFF, showing the concentration factor (C vol ) between the initial IP1 and the concentrated intermediate product 2 (IP2). (E) Protein concentration before and after TFF, showing the increased protein (C prot ) content due to the concentration step. C and D-E include N = 3 and N = 4 independent biological replicates, respectively, corresponding to the same independent WJ-MSC manufacturing batches followed throughout the manuscript. Data are presented as mean ± SD (D and E). ∗∗ p < 0.01 and ∗∗∗ p < 0.001 assessed by paired t test.
Article Snippet: MidiKros 20 cm 2 750-kDa mPES 0.5-mm hollow-fiber cartridge, sterile , Repligen , D02-E750-05-S.
Techniques: Filtration, Concentration Assay, Membrane, Gentle, Software, Biomarker Discovery, Protein Concentration
