For what it’s worth, I think pulling off this 3D printing hair follicles concept will be a lot harder than L’Oreal thinks. I’m not saying it’s impossible, but it’s really easy to say you’re going to do something like this, and much harder to actually do it.
The reason I think it’ll be so hard is (as I’ve posted about), the hair follicle is so freaking complex in its anatomy and the different kinds of cells involved.
Dr. Tsuji’s plan is something like a much simpler version of 3D printing – without the 3D printer. What he proposes is to create little proto-follicles or follicle precursors, in the lab, by positioning a wad of stem cells on the top, and DP cells on the bottom.
Picture a cell culture apparatus with lots of tiny “wells”. I imagine they’ll do something like this: they’ll place stem cells at the bottom of the wells, and DP cells on top (or maybe the reverse). Maybe they’ll use some kind of inter-cellular matrix to hold all the cells together. What matters is that you have one region of mainly stem cells (this would replicate the bulge region, which is about halfway up the length of the follicle), and an adjacent, lower region of mainly DP cells – this would replicate the dermal papilla. The thinking is that:
You definitely need both a stem cell and a DP cell region, and
To get the proper interaction between these regions, the 2 have to be separate, but connected.
The interactions which drive the hair follicle to start growing hair happen at the interface of the stem cell region and the DP cell region.
This is a much simplified version of a natural hair follicle.
The problem is that, In Real Life, the anatomy a hair follicle is quite a bit more complicated than just those 2 regions. And I imagine that Dr. Tsuji’s lab-grown “follicles” will look something like a little cylinder – straight up and down.
But a real follicle’s shape isn’t a simple cylinder. It’s more like a tear drop, and an angled one. It’s wider at the bulb (near where the papilla is), and it tapers gradually to get slimmer as you go up. The whole thing is angled in the skin. And the bulge region isn’t just a “level” of stem cells sitting above the papilla – in real life, it’s a very small locus of cells which sits adjacent to the epithelium surrounding the hair shaft.
Also, in real life, there are lots more different kinds of cells than just stem cells and DP cells in a follicle. There are keratinocytes (which they’re thinking, I’m sure, that many DP cells will become)… The epithelial cells surrounding the bulb and shaft, various types of interstitial cells, etc. Not to mention cells of the sebaceous gland, the erector pili muscle cells, etc. Also, in a real hair follicle, there are progenitor cells, which are (to simplify) the descendants of activated stem cells.
To me, in order to create a real, perfectly-working hair follicle that reliably grows hair that is cosmetically acceptable, you may have to have ALL the components I mentioned – not just the 2 levels that Dr. Tsuji is planning to use.
Not that I’m criticizing Dr. Tsuji’s plan… I hope it works. There is some evidence that it might produce some growing hair, although we really don’t know about the quality of the hair, the size, the reliability of cycling, etc. Those are all open questions for now.
Would be interesting to hear what James Bond has to say about all this… Do you think Dr. Tsuji’s idea can work?
There are 50,000 follicles already on my head in the balding areas. They are all intact, complete, and installed. All we need to do is correct whatever is going wrong with them.
But no, let’s dump all our efforts into creating 50,000 new ones and installing them and hoping that will be a more practical fix.
We should be glad the HM research world is not in charge of curing headaches. They would be trying to create replacement brains for everyone instead of developing Aspirin.