Mass Producing Stem Cells in Suspension

In her excellent story, medical writer Jovana Drinjakovic described what drove graduate student Yonatan Lipsitz, Ph.D. to become a biomedical engineer. Lipsitz wanted to see patients cured by means of stem cell therapies.

The problem, however, is cost and scale. Costs are too high. Scale is too low.

Laboratories around the world grow stem cells in batch quantities in small plastic dishes.

Lipsitz wanted to do something larger.

Scaling the process of growing billions and billions robust progenitor cell lines necessary to treat patients is both expensive and logistically very challenging. Lipsitz’s goal was to create a new form of bioreactor which could scale up cell production.

His answer was the suspension bioreactor.

With a suspension bioreactor, which has industrial volumes of liquid in them, Lipsitz expanded the quantity of human stem cells exponentially. Growing cells in liquid, not on the surface of petri dishes, lowered the cost dramatically and allowed Lipsitz to obtain billions of cells—enough, in theory, to treat many patients.

Studying mouse stem cells which, unlike human cells, can be readily expanded in suspension, gave him ideas on how to bolster cell growth. “We set out to find a cocktail of molecules and growth factors that could convert human stem cells into an alternative, high-growth state,” says Lipsitz. He was able to obtain yields of human stem cells in suspension more than five-fold greater than had been previously possible while still maintaining the cell’s pluripotency.

Lipsitz, now works as a scientist at a Boston biotechnology startup developing cell therapies.

He said, “Peter’s lab (where he did his stem cell research) combines fundamental understanding of stem cell biology with advanced technical engineering approaches, making it one of the most cutting-edge research environments in the stem cell field.” Lipsitz added that his job in Boston directly builds on the cell manufacturing skills he developed as a graduate student.