UCLA researchers eliminate major roadblock in regenerative medicine

In regenerative medicine, large supplies of safe and reliable human embryonic stem (hES) cells are needed for implantation into patients, but the field has faced challenges in developing cultures that can consistently grow and maintain clinical-grade stem cells.

Standard culture systems use mouse “feeder” cells and media containing bovine sera to cultivate and maintain hES cells, but such animal product — based media can contaminate the cells. And because of difficulties in precise quality control, each batch of the medium can introduce new and unwanted variations.

Now, a team of stem cell biologists and engineers from UCLA has identified an optimal combination and concentration of small-molecule inhibitors to support the long-term quality and maintenance of hES cells in feeder-free and serum-free conditions. The researchers used a feedback system control (FSC) scheme to innovatively and efficiently select the small-molecule inhibitors from a very large pool of possibilities.

The research findings, published today in the journal Nature Communications, represent a major advance in the quest to broadly transition regenerative medicine from the benchtop to the clinic.

“What is significant about this work is that we’ve been able to very rapidly develop a chemically defined culture medium to replace serum and feeders for cultivating clinical-grade hES cells, thereby removing a major roadblock in the area of regenerative medicine,” said Chih-Ming Ho, the Ben Rich — Lockheed Martin Professor at the UCLA Henry Samueli School of Engineering and Applied Science and a member of the National Academy of Engineering.

Unlike current animal product — based media, the new medium is a “defined” culture medium — one in which every component is known and traceable. This is important for clinical applications and as drugs or cells enter the world of regulatory affairs, including good manufacturing practice compliance and Food and Drug Administration supervision.