Evaluation of the effect of chronic hydrodynamical stresses on cultures of suspensed CHO-6E6 cells.

The effect of hydrodynamic forces on animal cell cultures, while extensively studied, still lacks significant, fundamental understanding. A previous manuscript reported on the acute exposure of CHO cells to hydrodynamic forces in a second generation convergent-divergent microfluidic device (Mollet et al., 2007).

Computer simulations of the energy dissipation rate in a fluorescence-activated cell sorter: Implications to cells.

Fluorescence activated cell sorting, FACS, is a widely used method to sort subpopulations of cells to high purities. To achieve relatively high sorting speeds, FACS instruments operate by forcing suspended cells to flow in a single file line through a laser(s) beam(s). Subsequently, this flow stream breaks up into individual drops which can be charged and deflected into multiple collection streams.

Acute hydrodynamic forces and apoptosis: a complex question.

A second generation flow contraction device was developed and modeled which allows cells to be subjected to well-defined hydrodynamic forces. Studies were conducted with this system on wild-type Chinese Hamster Ovary cells (CHO-K1) and a strain of CHO cells which expresses the human Bcl-2 triangle gene (CHO-bcl-2). In this study, the following questions were asked: (1) Does an acute hydrodynamic force induce apoptosis in wild-type CHO and CHO-bcl-2 cells? (2) Does the type of culture media make a difference with respect to the induction of apoptosis or necrosis? and (3) Does culture history affect induction of apoptosis or necrosis? The results obtained with this new flow contraction device and corresponding computer simulations are consistent with previously published studies with respect to the level of energy dissipation rate (EDR) required to create significant cell lysis.

Bioprocess equipment: characterization of energy dissipation rate and its potential to damage cells.

A study was conducted in which analytical, computational, and experimental measurements combined with analysis were made to characterize the local energy dissipation rate in a variety of conditions, vessels, and geometries that animal cells would encounter in typical bioprocessing situations. With no gas-liquid interfaces present, as expected, the local energy dissipation rate is typically orders of magnitude lower than what has been experimentally demonstrated to catastrophically damage typically used, suspended animal cells. However, local energy dissipation rates shown to remove animal cells from microcarriers are achievable under some normal operating conditions and geometries.

Synthesis and antitubulin activity of N1- and N4-substituted 3,5-dinitro sulfanilamides against African trypanosomes and Leishmania.

Thirty analogues of N(1)-phenyl-3,5-dinitro-N(4),N(4)-di-n-propylsulfanilamide (GB-II-5, compound 3), a new antikinetoplastid antimitotic agent, have been synthesized and evaluated. The addition of simple functional groups to the N1 aromatic ring generally decreases antiparasitic and antimitotic potency, but placement of a dibutyl substituent at the N4 nitrogen to give N(1)-phenyl-3,5-dinitro-N(4),N(4)-di-n-butylsulfanilamide (compound 35) augments antitrypanosomal and antileishmanial activity. Compound 35 possesses IC(50) values of 0.