In preparation for a space flight on STS-126, two in vitro culture systems were used to investigate macrophage
colony stimulating factor-dependent macrophage differentiation from mouse primary bone marrow cells. The patented
Techshot CellCult Bioreactor and the BioServe Fluid Processing Apparatus (FPA)1 were operated in different orientations
to determine their impact on macrophage growth and differentiation. Bone marrow cell parameters were determined after
cells were grown in FPAs incubated at 37°C in vertical or horizontal orientations, and macrophage cell recovery was
significantly higher from FPAs that were incubated in the horizontal orientation compared to “vertical” FPAs. Similarly,
when bone marrow cells were grown in the Techshot bioreactor, there were significant differences in the numbers of
macrophages recovered after 7 days, depending on movement and orientation of the bioreactor. Macrophage recovery was
highest when the patented bioreactor was rotated in the horizontal, x-axis plane (merry-go-round fashion) compared to
static and vertically, y-axis plane rotated (Ferris wheel fashion) bioreactors. In addition, the expression of F4/80 and other
differentiation markers varied depending on whether macrophages differentiated in FPAs or in bioreactors. After 7 days,
significant differences in size, granularity and molecule expression were seen even when the same primary bone marrow
cells were used to seed the cultures. These data show that culture outcomes are highly dependent on the culture device and
device orientation. Moreover, the impact of the culture system needs to be understood in order to interpret space flight
Cell differentiation, macrophage, fluid processing apparatus, space flight hardware.
116 Ackert Hall, Division of Biology, Kansas State University, Manhattan, KS 66506-4901, USA.