it have been done before. In older studies they even found out that if you want high density hair you need more blood flow into the skin or else it will die out.
But the problem with mice studies is, that they have a hard time to translate into human studies.
Maybe you are right, but I think this is the first time someone to use 100% human stem cells (iPSCs). This is very big difference. Everyone else before used mixed human and mice cells.
George Cotsarelis quote for this discovery:
When hair follicles were first generated from stem cells that had been isolated from adult mouse skin
1, Jay Leno — a former host of US talk show
The Tonight Show — joked that scientists “cured baldness … at least in mice”. Sixteen years on, the current host will have the opportunity to mention that scientists have ‘cured’ baldness in humans, now that Lee
et al.
2,
writing in Nature, have regenerated hair follicles from human stem cells. This achievement places us closer to generating a limitless supply of hair follicles that can be transplanted to the scalps of people who have thinning or no hair. Moreover, if the approach reaches the clinic, individuals who have wounds, scars and genetic skin diseases will have access to revolutionary treatments.
The later he added this:
However, several questions remain before this therapeutic approach becomes a reality. For instance, how efficiently and reproducibly do hairs develop? How many cells are needed to eventually form a hair follicle once grafted? Lee
et al. began to answer the first of these questions by showing that a separate laboratory could grow hair in organoids using the same culture conditions. However, dealing with variability between individual stem cells and between the stem cells from different people are daunting challenges.
Several other aspects of the authors’ approach will also need to be optimized before it can move to the clinic. The hairs that grew in the current study were small; in future, further optimization of culture conditions will be needed to form large scalp hairs. Better characterization of some components used in the culture cocktail — such as a protein mixture called Matrigel — will be necessary to ensure that they comply with good manufacturing practices.
Despite these caveats, Lee and colleagues’ study is a major step towards a ‘cure’ for baldness in humans, and paves a way towards other, greater therapeutic possibilities. At a minimum, it is worth a shout-out on a late-night show. The work holds great promise of clinical translation — we are confident that research will eventually see this promise realized.
Even Stemson (Alexey Terskikh) used mixed human and mice cells.
https://www.eurekalert.org/pub_releases/2019-06/sbpm-fhf062519.php
“The current protocol relies on mouse epithelial cells combined with human dermal papilla cells. The experiments were conducted in immunodeficient nude mice, which lack body hair.“
I agree with you that mouse studies not always give impressive results in humans, but modern science have many other tools to verify if something is working or not. Plus, science based on mouse and animals studies gave us many incredible breakthrough discoveries last century.
One of the tools is creating human organoids from stem cells (mostly iPSCs).
https://www.sciencedirect.com/science/article/pii/B9780128191781000459
