Remember the 14-day rule?
This rule, which isn’t really a rule, has been a widely-adopted guideline to stop growing human embryos in the lab after two weeks.
In 2021, the International Society for Stem Cell research or ISSCR, dropped the two week guideline. Without a clear replacement. Although I’m a long-standing member of ISSCR, to leave things open-ended seemed unnecessarily risky to me. I still feel that way.
Now, a group of respected experts has proposed a 28-day limit instead.
Switching from the 14-day rule to a new 28-day rule on human embryo growth in the lab
Here’s the Nature paper on the proposal: Human embryo research: how to move towards a 28-day limit The decades-old limit on how long human embryos can be grown in culture is under debate. A new road map outlines how to extend the length of culture responsibly.
The authors make some solid arguments overall.
For example, they write, “There are good reasons to draw the line at 28 days. The closure of the neural tube provides a clear stopping point that makes governance and oversight easier. The availability of aborted material that is donated to research is much higher after 28 days. And, after four weeks, the body plan is largely set. Many individual tissues and organs develop relatively independently after 28 days, and so can be studied using aborted tissue without needing whole embryos.”
What would be the pros of a 28-day rule?
Why allow 2 more weeks of human embryo growth in the lab?
More science could be done. We’re talking about research that might prevent disease and help with infertility treatments. Many important events happen between 2 and 4 weeks of development that could be carefully studied with a 28-day cutoff.
The authors write, “Collectively, we think that extending the embryo-culture limit to 28 days, or neural-tube closure, would offer the promise of unique scientific and clinical insights. However, any increase must not be merely legislative — it should involve nuanced ethical oversight and careful dialogue with understanding from both sides.”
This makes good sense both in terms of the research potential and the need for some contemplation as well as dialogue here.
A new four-week limit has some potential downsides.
What about possible cons?
The main risk here is that the new rule could stir pushback that more broadly hurts important research.
In the U.S. we’re at a precarious moment in history for embryo-related research. A new ban on hESC research funding is already very possible in the U.S.
Why might there be more pushback on a 28-day rule versus the current 14-day rule?
Let’s ask another question: would an embryo grown to 28 days in the lab have a beating heart toward the end or would that only happen with embryo implantation in utero? It seems likely that a heartbeat would become apparent around days 20-21. That is a milestone that some folks use to define when a human life begins. Others view life beginning at conception so might not be more concerned about 28 versus 14 days. I don’t see things in either of these ways, but many others do.
A 28-day human embryo is going to look much more identifiable than a 14-day one too.
What do you all think?
Is 28 days a better stopping point than 14 days? Would you let in vitro embryo growth go even longer than 4 weeks?
Another relevant question is whether there should be any limit on the growth of human embryo models. As these models, made generally from pluripotent stem cells, become more similar to the real thing and extended in vitro culture methods advance, there are plenty of things to discuss.
Okay, speaking of reproduction, let’s move on to a cord blood story.
Duke & Cryo-Cell conflict: a comprehensive history
I have a new column out at STAT about the ongoing conflict between Duke and cord blood banker Cyro-Cell. Their deal is dead.
I’ve covered these past partners for many years and was surprised last year to see signs that the partnership might have serious issues.
In the process of writing the new column, Lessons from Duke’s nuked mega cord blood deal with Cryo-Cell, none of the parties involved would comment.
Vinay Prasad overrules scientists; other FDA & NIH news
In my view, so far the biomedical leadership in the current administration is placing politics over sciences. For example: Top F.D.A. Official Overrode Scientists on Covid Shots, NYT. Inside the FDA, it feels like politics is mostly trumping science. I think we’re going to see problems with cell and gene therapy policies and oversight too.
It’s happening at NIH as well. We have this: Exclusive: NIH still screens grants in process a judge ruled illegal, Nature.
As I was thinking about these recent developments, I also saw this: FDA Eliminates Risk Evaluation and Mitigation Strategies (REMS) for Autologous Chimeric Antigen Receptor CAR T cell Immunotherapies, FDA. However, in talking to CAR T and gene therapy researchers, this REMS change is seen as a positive move by the FDA and will lead to more people being helped probably without substantial new risks.
So, some changes moving forward may also be positive.
Other recommended regenerative reads
- Durable HTT silencing using non-evolved dCas9 epigenome editors in patient-derived cells, Mol Ther Nucleic Acids.
- Virtual Cell Challenge: Toward a Turing test for the virtual cell, Cell.
- Changing one gene can restore some tissue regeneration to mice, Ars Technica.
Update on Fountain Life and stem cells
Over the years, I’ve been unclear on whether wellness firm Fountain Life, founded by some of the leaders of Nasdaq-listed biotech Celularity, was offering or was going to offer stem cells in the future.
Maybe things are clearer now? The Fountain Life Florida clinic location now markets stem cell offerings including for longevity. The website says, “The program features stem cell treatments to regenerate damaged tissues, platelet-rich plasma (PRP) therapy to accelerate healing, and advanced tissue regeneration techniques to restore function” and “Lower biological age: Slow aging at the cellular level with regenerative therapies like stem cell treatments.”
Blast from the past
My video fact-checking head transplants. Please subscribe to The Niche stem cell channel on YouTube.