Just to try and get the tread back on track.
Riken is as we know on their way to try and do some regenerative medicine with hair follicles among other things.
Riken Link
" In the future, this technique could be used for functional skin transplants in burn victims and other patients who require new skin, or even to combat hair loss. Importantly, the lab-grown skin exhibited sustainable hair cycles, indicating functional regeneration."
if we go further in Riken notes
"These first steps toward creating living 3D tissue in the laboratory are truly groundbreaking. RIKEN is leading the way in this field that was considered science fiction just a few years ago, and which could ultimately create a world in which injured tissues are commonly replaced with tissue grown outside the body."
If we then look into the 3D tissue research, then we come upon studies like this
Tissue engineering of human hair follicles using a biomimetic developmental approach that shows to ability and challenges of high density.
"we increased the HF density from 81 HF to 255 HF per cm2 (Fig.
4a−c and Supplementary Movie
1) using 3D-printed high HF density molds. The first set of experiments did not result in hair formation; instead, we observed substantial necrosis at the center of the grafts due to lack of host vascularization in the grafts."
And we do already know from Shenseido study that we need that bloodflow/ vascurlarization to the new hair follicles.
"To generate a vascular bed, we encapsulated GFP-tagged human umbilical vein endothelial cells (HUVECs) in the dermis of our HSCs together with the dermal fibroblasts"
"Hair induction in HSCs grafted onto mice
Four to five weeks after grafting our vascularized HSCs at a high follicle density of 255 HF per cm2 onto immunodeficient nude mice, we observed substantial hair growth in the grafts, whereas the HSCs prepared with FB aggregates did not induce hair formation (Fig.
5a, b). In the grafting experiments, we used ten mice per condition. Our vascularization strategy enabled the survival of
seven out of ten grafts, both for HSCs prepared with DPCs as well as FBs as a negative control.
Grafts from four out of these seven mice successfully generated human HFs, whereas none of the seven mice in the FB control experiment induced hair formation"
As it can be seen there are still challenges with this method.
If we look at the 3D printing technique where it was last year
Scientists at the University of Twente have managed to 3D print structures with living cells, which could boost the field of tissue engineering.
"The researchers wanted to use this technology to produce their 3D structure but the speed at which cells leave the chip was too slow, meaning it would take 1
7 hours to produce a structure with a size of 1 cubic centimeter."
"This drove the group to look at using jets to speed up the process. They built two jets that were able to safely move fluids 100 to 1,000 times faster than in a microchip. Not only did this mean that the time taken to build a structure was
reduced down to around 2 minutes, but by choosing specific combinations of fluids that react, new materials could be generated upon collision.
The researchers used this technique to build 3D structures with a similar internal structure to that of natural tissue that could be filled with cells and fluid. Their approach offers a promising alternative to current 3D printing techniques that tend to use heat or UV light, which damage living cells."
Too me it looks like we have multiple players on the 3D tissue printing area, and this only a few out of many engaged with this area.
Maybe some of the highlighted things with provided higher success rate with high density graft and vascularization is one of the challenges that RIKEN also fight with before they start on human trails, or maybe have solved, and then there is the technical aspect of it that if they used some technique that used 17 hours to make 1 cm^3 and with new technique down to 2 minutes is also some of those changes RIken have hoped for.
Who knows, its a bet anyways on what they are working on around the world.