More On Petaka Mini Bioreactors

Getting Culture Conditions Right Every Time

I would like to provide yet more information on the capabilties of our new and innovative Petaka Mini Bioreactors. This posting focuses how oxygen concentrations are tightly controlled in a way that is consistent with the cultured cells natural environment.

The length and cross-section of the respiratory duct is purposely engineered to partially restrict the diffusion of oxygen from the high levels of ambient air to create lower, physiologic levels of dissolved oxygen in the reaction chamber. In accordance to Fick’s Law, as oxygen is consumed inside the culture chamber, decreasing the partial pressure of oxygen in the media, oxygen diffuses in from the outside atmospheric (higher) partial pressure, through the respiratory duct, to the lower partial pressure inside. Diffusion is proportional to the concentration gradient, as regulated by the engineered design of the respiratory duct, and occurs entirely spontaneously and without any manual intervention whatsoever.

Image: Petaka®G3 Ducted Respiratory Chamber (DRC). (1) cell culture chamber;(2) injection port; (3) respiratory duct; (4) 0.2μ filter; (5) water vapor condensers and capillary breakers; (6) unique barcode. The DRC is shown upright in a silicone stand (7).

At the same time, the respiratory duct partially retains carbon dioxide from cellular metabolism to maintain a physiologically normal mild acidosis to balance pH. All gas exchange with the outside environment occurs via a 0.2 micron filtered vent, preserving the internal sterility of the device but allowing exchange of gas diffusion and flow to prevent pressurization issues when filling and emptying the bioreactors.
Therefore, cell culture in DRC’s/Petaka G3 does not require supplemental oxygen-nitrogen balancing, CO2 and humidity sources, eliminating the entire panoply of gas tanks, regulators, sensors, microprocessors and water pans. This creates a double benefit: not only are cells cultured in more normal physiologic conditions, but the mechanics, logistics, risks and costs of cell culture are greatly simplified and reduced.

The Results are Stunning!

Here are result using Petaka® G3 LOT for culturing our UCB Derived hMSCs and Mouse MSCs.

Images: (A) Immuno-fluorescence microscopy of a mouse MSC in differentiation progression. Culture under 20 mmHg of O2 partial pressure. Red fluorescence positive staining of GFAP. hMSC 3 hours after seeding in Petaka G3 with low serum media and without matrix (B) and 96 h later (C). Photos: Jim Musick. Vitro-Biopharma. September, 2012.

Next up using Petaka DRCs for GMP. Stay tuned.

True Physiologic Conditions in Cell Culturing

The Petaka Advantage!

A cornerstone of Neuromics' strategy is to enable better science by finding ways to help our customers and collaborators to both improve and lower the overall costs of their cell based assays.

We embrace new technologies if they prove capable of providing cell culture environment that more closely mimic in vivo environments. This enables basic and drug discovery researchers learn more about the true potential of targets. More informed decisions early in the process reduce downstream costs.

This is why the use of engineered mini bioreactors with Ducted Respiratory Chambers (DRCs) like the Petaka® G3 LOT needs to be considered. (detailed information @ Ducted Respiratory Chamber Bioreactors.© 2012 Genetic Engineering & Biotechnology News All Rights Reserved). Instead of attempting to impose “normal” gas conditions on the cells through active incubator controls, this system passively allows cells to maintain their own oxygen, carbon dioxide, and humidity levels.

Image: Petaka's DRC design. The cell culture chamber is isolated on the injection side from the atmosphere by a self-sealing silicone injection port that allows the closed introduction of media and cells, including most eukaryotic cells types, small early-stage embryos, tissue fragments, and even needle biopsies.

Because the cells control their own gas environment, there is little effect from outside gas conditions, and the DRC is effective in atmospheres from 500 meters below sea level up to elevations of 4,000 meters, and in relative humidity levels between 10% and 100%.

Figure: Self-regulating gas management in the DRC. Cells consume O₂, with restricted O₂ ingress, causing a first proliferative cell phase to evolve into a second differentiating cell phase for protein production and gene expression.

The DRC changes the paradigm of cell culture, replacing nearly a century of active attempts to humanly intervene to manipulate gas exchange with a self-regulating design driven by natural laws of diffusion to create dependable, and truly physiologic, gas environments.