Increasing efficiency of human mesenchymal stromal cell culture by optimization of microcarrier concentration and design of medium feed

Establishing the scalable manufacture of primary human T‐cells in an automated stirred‐tank bioreactor

“…To overcome these challenges, clinical research and commercial groups have used the use of rocking motion bioreactor systems (e.g., GE Healthcare's WAVE bioreactor or BIOSTAT RM from Sartorius Stedim Biotech), which improve the homogeneity of the culture, sampling and implementation of process control strategies (Marsh et al, 2017;Vormittag et al, 2018). However, there have been extensive studies in the literature which have demonstrated the potential to culture numerous mammalian and human cells under both transitional and turbulent fluid dynamic conditions for both free suspension cells (Nienow, 2006) and adherent cells on microcarriers (Chen, Chew, Tan, Reuveny, & Weng Oh, 2015;Nienow et al, 2016;Rafiq et al, 2017). Some early work was successful in demonstrating the growth of T-cells in both spinner flasks and small bioreactors (Bohnenkamp, Hilbert, & Noll, 2002;Carswell & Papoutsakis, 2000) but neither used Dynabeads for cell activation.…”

“…This lack of activity is likely due to the common unsubstantiated concern that such cells are too fragile to withstand the fluid dynamic environment found in stirred-tank bioreactors. However, there have been extensive studies in the literature which have demonstrated the potential to culture numerous mammalian and human cells under both transitional and turbulent fluid dynamic conditions for both free suspension cells (Nienow, 2006) and adherent cells on microcarriers (Chen, Chew, Tan, Reuveny, & Weng Oh, 2015;Nienow et al, 2016;Rafiq et al, 2017).…”

Serum-free media formulations are cell line–specific and require optimization for microcarrier culture

“…This SFM (BTI-SFM-1) supported cell growth on monolayer surfaces coated with fibronectin, with final cell densities similar to with the use of serumcontaining media ( Figure 1A; cell densities at day 4: a10, 4.1 Â 10 4 cells/cm 2 ; BTI-SFM-1, 4.3 Â 10 4 cells/cm 2 ; P > 0.05). However, in contrast to serumcontaining medium (a10), which supported cell proliferation on microcarriers in static as well as in agitated conditions (up to 12-fold expansion on microcarriers in 8 days) [47,49,50], this medium (BTI-SFM-1) failed to support BM-MSC-3 cell growth when cells were seeded on microcarriers, even in static culture ( Figure 1B; cell densities at day 4: a10, 3.9 Â 10 4 cells/cm 2 ; BTI-SFM-1, 1.4 Â 10 4 cells/cm 2 ). Supplementing BTI-SFM-1 with serumpurified albumin gave varying results (4.7 Â 10 4 cells/cm 2 with the use of BTI-SFM-1 with albumin A versus 1.9 Â 10 4 cells/cm 2 with the use of BTI-SFM-1 with albumin B; Figure 1B), indicating differences in albumin-associated factor composition from different sources.…”

“…Some studies report differences in cell growth and nutrient metabolism between monolayer and microcarrier cultures in both serum-containing medium and SFM culture systems [47,50,58,59] [60]] show the feasibility of reaching the goals of billions of cells in production with the use of multi-liter bioreactors. SFM may still contain a range of growth factors, hormones and proteins derived from animal sources.…”

Limitless starting materials for large-scale manufacture of MSCs – what does the future hold?

“…Processes involving 3D microcarrier culture in bioreactors have shown promise, but challenges remain and " ...induced pluripotent stem cell-derived mesenchymal stem cells have the potential to solve the biggest challenge associated with mesenchymal stem cell products -the quest for truly scalable, consistent manufacture. " Editorial Kelly most studies using these approaches have utilized small bioreactors that may not be scalable [10][11][12]. Additionally, even if successful scale-up to large bioreactors can be achieved, it cannot be assumed that MSCs expanded at large scale will retain the same functional properties, given the propensity of MSCs to change in culture.…”