Following informed consent of the mother, we isolated MSC from the umbilical cord tissue of a term, healthy infant under current good manufacturing practice (cGMP) conditions based on a protocol we previously described.
15 (link) Briefly, we dissociated the disinfected, mechanically disrupted umbilical cord tissue using DNAse (F. Hoffmann-La Roche), hyaluronidase (Riemser Pharma) and collagenase (Nordmark Arzneimittel) and cultured so-obtained cells for two passages on membrane-based culture systems (Corning) in humidified, hypoxic (5% O
2, 5% CO
2) atmospheres to maintain their potency and avoid onset of cellular senescence during cell production.
16 (link) GMP-compliant Dulbecco’s low glucose Modified Eagle Medium (Thermo Fisher) supplemented with 10% platelet-rich plasma
17 (link) was used as culture medium. We froze down the cell product at 8 × 10
6 cells per mL in 90% human serum albumin, (50 mg/mL solution; Baxter, Deerfield, IL, USA) and 10% dimethyl sulfoxide (WAK-Chemie) in a fixed-rate freezer for storage in the vapor phase of liquid nitrogen.
Characterization of the MSC product (
Table 1) as per ISCT consensus criteria
18 (link) was performed using freshly thawed, once-rinsed passage 2 cells prepared in exactly the same way as for injection. Flow cytometry, analyses of colony formation and tri-lineage differentiation potential were performed as previously described.
19 (link) We confirmed immunomodulatory potency of the employed cells by successful induction of indoleamine 2,3-dioxygenase (
IDO) transcription upon 24 hours of stimulation
20 (link) with 10 ng/mL interferon-γ (R&D Systems), using a validated
IDO primer assay (QuantiTect, Qiagen). To analyze secretion of stanniocalcin-1 (R&D Systems) and FGF-10 (Abbexa), both suggested to mediate MSC’s effects in the (newborn) lung,
3 (link),21 (link),22 (link) we obtained 24-hour, cell-free conditioned medium as described.
19 (link)
Möbius M.A., Seidner S.R., McCurnin D.C., Menschner L., Fürböter-Behnert I., Schönfeld J., Marzahn J., Freund D., Münch N., Hering S., Mustafa S.B., Anzueto D.G., Winter L.A., Blanco C.L., Hanes M.A., Rüdiger M, & Thébaud B. (2023). Prophylactic Administration of Mesenchymal Stromal Cells Does Not Prevent Arrested Lung Development in Extremely Premature-Born Non-Human Primates. Stem Cells Translational Medicine, 12(2), 97-111.