The Suzuki±Miyaura cross-coupling reaction using heterogeneous Pd/C has a homogeneous component. The soluble palladium concentration increases during the reaction reaching a maximum at ca. 90% conversion before falling to < 4 ppm.

Cultures of umbilical cord blood and mobilized peripheral blood mononuclear cells were carried out in a stirred bioreactor with pH and dissolved oxygen control. Expansion of total cells and colony-forming units granulocyte-macrophage was greatly enhanced by the use of a cell-dilution feeding protocol (as compared to a cell-retention feeding protocol). The specific oxygen consumption rate (qO2) for these cultures ranged from 1.7 x 10(-8) to 1.2 x 10(-7) micromol/(cell.h). The maximum in qO2 for each culture closely corresponded with the maximum percentage of progenitor or colony-forming cells (CFCs) present in the culture. The maximum qO2 values are slightly less than those reported for hybridomas, while the lowest qO2 values are somewhat greater than those reported for mature granulocytes. Examination of the ratio of lactate production to oxygen consumption in these cultures suggests that post-progenitor cells of the granulomonocytic lineage obtain a greater portion of their energy from glycolysis than do CFCs. The different metabolic profiles of CFCs and more mature cells suggest that monitoring the uptake or production of oxygen, lactate, and other metabolites will allow estimation of the content of several cell types in culture.

The ability to culture hematopoietic cells in readily characterizable and scalable stirred systems, combined with the capability to utilize serum‐free medium, will aid the development of clinically attractive bioreactor systems for transplantation therapies. We thus examined the proliferation and differentiation characteristics of peripheral blood (PB) mononuclear cells (MNC), cord blood (CB) MNC, and PB CD34+ cells in spinner flasks and (control) T‐flask cultures in both serum‐containing and serum‐free media. Hematopoietic cultures initiated from all sources examined (PB MNC, CB MNC, and PB CD34+ cells) grew well in spinner vessels with either serum‐containing or serum‐free medium. Culture proliferation in spinner flasks was dependent on both agitator design and RPM as well as on the establishment of critical inoculum densities (ID) in both serum‐containing (2 × 105 MNC/mL) and serum‐free (3 × 105 MNC/mL) media. Spinner flask culture of PB MNC in serum‐containing medium provided superior expansion of total cells and colony‐forming cells (CFC) at high ID (1.2 × 106 cells/mL) as compared to T‐flask controls. Serum‐free spinner culture was comparable, if not superior, to that observed in serum‐containing medium. This is the first report of stirred culture of PB or CB MNC, as well as the first report of stirred CD34+ cell culture. Additionally, this is the first account of serum‐free stirred culture of hematopoietic cells from any source. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 59: 534–543, 1998.

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