|Stem cell science can sometimes feel like Goldilocks, but instead of trying to find a bed not too hard and not too soft it is trying to find a procedure that gets the cells to do just exactly what you want.|
This month’s report, as you might expect, has my take on the research out of Harvard’s Brigham and Woman’s Hospital about turning adult cells into embryonic-like stem cells merely with exposure to mild acid. With that research receiving ample debate by others, I will not expand here on my call for the need to replicate the work that I made in my main monthly report. Instead I would like to highlight in this blog another research methods paper out of the Brigham.
A different team there, working with a team in Singapore, developed a procedure to load progenitor cells with tiny packets carrying molecules that can direct the fate of how the cells mature. This work has the narrative of the children’s story in which Goldilocks was testing beds to find one that wasn’t too hard or too soft. Researchers have long been able to treat stem cells in the lab with various chemicals or genetic factors and get them to become the type of progenitor tissue or adult tissue they want in a dish. They have also begun to perfect loading nanoparticles with those same factors and inserting them into cells hoping they could help drive progenitor cell fate after transplantation. But neither process quite gets to the ultimate goal of a well-defined cell population that persists in the same role days and weeks after transplantation.
When you do the manipulation in the lab you loose control of the cells’ fate after transplantation. With the nanoparticles, the tiny delivery packets are so small the cells’ natural transport machinery has no problem grabbing the foreign particles and shipping them out of the cell within a day or two, or sometimes only hours. So, the Brigham team created slightly larger micro-particles that seem to persist in cells for weeks after transplant continuing to direct their fate.
The researchers have in essence turned cells into pre-programmable units. The micro-particles can be loaded with molecules that tell the cells how to mature, but they can also direct how the cells function. Since mesenchymal stem cells are often used to try to reduce inflammation or alternately to stimulate growth of new blood vessels, they could be loaded with particles that would instruct them to promote one specific function. The authors suggest cells could be pre-loaded and cryo-preserved for when patients need them. This could be the Brigham’s most practical new method this month.
My full report is available online, along with links to my reports from previous months.