Many stem cell projects expand to a point where standard culture methods—plates, dishes, flasks, etc.—no longer yield sufficient cells to meet the growing needs for differentiation and regenerative medicine. At this point, larger scale options are required. Traditional bioreactors provide large volume cell culture of liters to hundreds of liters, but they are expensive to buy and expensive to operate. New small scale bioreactors fill the niche between these two extremes perfectly, providing increased cell production over plates or dishes, while being cost-effective to buy and operate.
ABLE Biott Disposable Bioreactor
The ABLE bioreactor system provides standard 30 mL bioreactor and 100 mL bioreactors containing a unique impeller design to provide low-shear agitation. The vessel itself is made of high-density polycarbonate, and it is surface-treated for biocompatibility to ensure compatibility with stem cell culture. The 5 mL and 30 mL vessels provide a polypropylene cap which is equipped with a filter to allow for passive, sterile gas exchange when the vessels are incubated in a standard cell-culture incubator. The 100 mL and 500 mL flasks come with ports to facilitate exchange of gasses.
Magnetic Stir System Configuration
The ABLE Bioreactor Magnetic Stir System consists of two components. The heat-generating controller module sits outside the incubator and provides for precise, reproducible agitation control.
The motor and the 6-position stirring module (Cat. No. ABBWBP03N0S-6 for the 30 and 100 mL flask stirrer; Cat. No. ABBWBP05N0S-6 for the 5 mL flask stirrer) sit inside the incubator, and provides constant, controlled agitation without excessive heat generation, leading to consistent day-to-day and run-to-run performance.
Bioreactor Culture of Stem Cells
Shear stress can inhibit the growth of stem cells and, in some cases, promote differentiation . The unique impeller design of the ABLE Bioreactor is optimized for the culture of stem cells and is designed to minimize the shear stress associated with agitation. The bioreactor allows for the flexibility or using single-cell suspension, passaged colony fragments, or miniorganoids for the seed stock, while providing rapid growth to high density. Culture of stem cells in the bioreactor gives uniform spheroid cell clusters with diameters of 200 – 300 μm.
Figure 1: Spheroids of iPSC line 1231A3. Human iPS cells were grown in StemFit medium demonstrating the consistency of spheroid sizes after 4 days cultivation in the ABLE 30 ml Disposable Bioreactor at 40 rpm.
Figure 2: Stem Cell Growth Curve. Human iPS cells were harvested and dissociated into single cells using TrypLE Select (ThermoFisher), washed and counted. The single-cells were then seeded at 105 cells/mL in StemFit medium supplemented with 10 μM Y27632 and transferred to the ABLE 30 mL Disposable Bioreactor with constant spinner agitation at 55 rpm. Cells spheroids were dispersed by TrypLE Select, stained with trypan blue, and counted.
Bioreactor-aided differentiation of iPSCs
In our laboratory, we have adapted our cardiomyocyte differentiation protocol to accommodate the use of the bioreactor. Use of the bioreactor has enabled us to increase the yield of cardiomyocytes four-fold, while reducing medium usage by more than 15%. Adoption of bioreactor culture has also improved the quality of the cardiomyocytes obtained.
Figure 3: Cell yield and medium usage for bioreactor-based differentiation (relative to 2D culture method).
Figure 4: Images of cardiomyocyte spheroids differentiated on culture dishes, (left panel), and in the bioreactor (right panel), showing increased cell density in the bioreactor culture.
Cost-effective mass stem cell culture
The ABLE bioreactor system provides a cost-effective laboratory scale solution for scaling up culture for stem cell projects. The system is engineered to provide consistent results with out worry about shear stress or excess heating. The ABLE bioreactor system also provides an intermediate scale-up option for projects where scale up to industrial culture is desirable, e.g. for emerging regenerative medicine therapies.
- Matsuura et al. Fabrication of mouse embryonic stem cell-derived layered cardiac cell sheets using a bioreactor culture system. PLoS One 7(12) (2012)
- Matsuura et al. Creation of human cardiac cell sheets using pluripotent stem cells. Biochemical and Biophysical Research Communications 24:425 (2012)
- Toh et al. Fluid shear stress primes mouse embryonic stem cells for differentiation in a self-renewing environment via heparan sulfate proteoglycans transduction. The FASEB Journal 25:1208 (2011)
Editors note: This post was originally published in February 2018 and has since been updated for accuracy and clarity.