Each month CIRM President Alan Trounson gives his perspective on recently published papers he thinks will be valuable in moving the field of stem cell research forward. This month’s report, along with an archive of past reports, is available on the CIRM website.
Last month’s blog discussed two papers that made advances in “dual modality” therapies; both papers combined cell therapy and gene therapy. This month I want to highlight two papers that both provide examples of another trend in regenerative medicine research. Each relies on two different fields of scientific inquiry. One combines stem cell science and chemical biology and the other combines stem cell science with nanoparticle science.
A CIRM-funded team at Sanford-Burnham Research Institute found a compound that can efficiently direct embryonic stem cells to become heart muscle and not become other types of tissue. They developed a biology-based assay that let them quickly detect whether or not cells were moving toward becoming heart tissue. They then used an existing library of small molecule compounds and screened 17,000 compounds against their assay, and they found the one highly effective molecule.
This compound, or one closely related to it, could be used to produce enough heart tissue in the lab for transplantation. It could also potentially be used directly in patients to improve the efficiency of their own existing stem cells. We blogged about that work here.
The second paper involved a number of institutions in Taiwan as well as UC San Francisco. They used nanotechnology to make something work that theoretically made sense, but up to now has not worked. A growth factor called VEGF can summons stem cells to a site and coax new blood vessels to grow. So, several teams have tried injecting it into the site of injury following a heart attack, but this hasn’t resulted in much vessel growth. It turns out the growth factor does not stick around long enough to do its job. The current team built tiny scaffolds out of nanofibers and loaded them with VEGF. When they injected these into the site of injury they could detect 70 percent of the fibers still there a month later. They also saw significant blood vessel growth, both small capillaries and larger vessels and some new heart muscle. All three would be needed for effective heart attack repair.
This team also crossed another important barrier to clinical use of these complex materials. They used a pig model, and these larger animals models will likely be necessary to gain regulatory approval going forward, but they have rarely been used with bio-engineered materials up until now.
These papers highlight something that has been a bit of a soapbox for me, and that is the power and importance of cross-disciplinary research. This is why I championed our “Creativity Awards” that place high school students in a stem cell lab for the summer, but requires that they combine stem cell science with a second discipline. My colleagues have written about that program here.
My full report is available online, along with links to my reports from previous months.