Cytocentric Blog

Why Should We Care About In Vitro Pericellular Oxygen?

Alicia D. Henn, CSO BioSpherix

An important new publication in Stem Cells and Development by Tiwari et al in Australia has brought a critically important in vitro oxygen diffusion issue to the forefront[1]. In a murine model, they explore optimum oxygen levels for best in vitro expansion of HSC for transplant.

 

The Findings

They report:

- It took between 4 and 19 hours for human umbilical cord blood CD34+ cells pericellular oxygen to reach steady-state at ~4% O2 (in the incubator set to 5%) O2 and at about 18% O2 (incubator set to 20%)

- A gradual decrease in HSC pericellular oxygen levels in 24-well plates in static culture over 7 days with the incubator set at 5% or 20% O2

- Orbital shaking, “dynamic” incubation, of the plate at 5% O2 maintained pericellular oxygen levels at 4% longer even as cell numbers increased to numbers 70% higher than without shaking

- Cells incubated at 20% O2 also saw increased cell expansion with shaking

- HSC incubated with shaking at 5% O2 expanded the most as assessed by colony forming assay and flow cytometry, producing multiple hematopoietic cell types

- The bone marrow and spleen of immunodeficient mice were engrafted better by HSC (a mix of cell types including progenitors) incubated at 5% O2 with shaking

Read more...

no sprayer 01

How to Clean a Closed Environment for Cells: Resisting the Misting

In a closed system like a barrier isolator, there are few routes for disinfectants to leave and no way for contaminants to float in.

In an open laboratory, you can spray surfaces liberally with disinfectant and it all evaporates into the room air. Keeping surfaces wet with disinfectant for maximum contact time is the major concern.

It is a big change, moving from an open lab, which exists in a constant state of high microbial contamination risks, into the closed Xvivo system, a very low risk environment. A risk-based balance has to be struck between much lower risk of contamination and the higher risk of disinfectant fume build-up.

Read more...

cytocentric visionaries jj p3

Cytocentric Visionaries: Jan Jensen, Trailhead BioSystems 

Part Three: Full-time Oxygen Control and Aseptic Conditions are Critical for Automated Protocol Optimization

Alicia Henn, Chief Scientific Officer, BioSpherix

In Part Two, we discussed Trailhead’s unbiased system of cell signaling optimization for differentiation. Today, Dr. Jan Jensen. CSO of Trailhead BioSystems discusses full-time optimization of cell culture conditions with us.

Read more...

cytocentric visionaries jj p2

Cytocentric Visionaries: Jan Jensen, Trailhead BioSystems 

Part Two: Controlling Stray Cell Fates in Culture

Alicia Henn, Chief Scientific Officer, BioSpherix

In Part One, we discussed Trailhead’s unbiased system of cell signaling optimization for differentiation. Here we continue our conversation with Dr. Jan Jensen. CSO of Trailhead BioSystems in Cleveland, OH. Today we talk about cell fate and reprogramming.

 

Read more...

cytocentric visionaries jj p1

Cytocentric Visionaries: Jan Jensen, Trailhead BioSystems 

Part One: Unbiased Cell Science: Don’t Try to Out-Think Nature

 

Alicia Henn, Chief Scientific Officer, BioSpherix

Dr. Jan Jensen is the E. J. Brandon Endowed Professor in Diabetes Research at the Cleveland Clinic and also CSO of Trailhead BioSystems. Trailhead uses a unique combination of advanced technologies to define optimized combinations of growth factors that will efficiently guide cell differentiation from the embryonic state through specific cell lineage pathways.

Combining a Design of Experiments approach with robotics, mathematical modeling, high throughput gene analysis, and Cytocentric Isolators, Trailhead optimizes cell media 12 factors at a time to achieve step-by-step cell type conversion rates of well over 90%.

Here, Alicia talks with Dr. Jensen about how they had to let go of the past to progress.

Read more...