tsuji has grown actual human hair on human skin that was put on a mouse, what do you think would happen if you'd take those hairs that have already been made and verified to be indeed human and having a proper hair cycle and transplant it onto the human scalp?
damn I want to see what happens then, I guess hopefully next year we will see
I don’t know, I sit in anticipation just like you… Hair follicle Neogenesis has never been done in human models YET. And other labs have tried with extracted papilla (mesenchymal) cells and epidermal cells, interchanging tissue and cells between mice and human models, etc.
Here’s something that is quite interesting from a different research paper 2015:
This review summarizes current advances in the different experimental strategies to regenerate or neogenerate hair follicles, with emphasis on those involving neogenesis of hair follicles in adult individuals using isolated cells and tissue engineering. Most of these experiments were performed using rodent cells, particularly from embryonic or newborn origin. However, no successful strategy to generate human hair follicles from adult cells has yet been reported. This review identifies several issues that should be considered to achieve this objective. Perhaps the most important challenge is to provide three-dimensional culture conditions mimicking the structure of living tissue. Improving culture conditions that allow the expansion of specific cells while protecting their inductive properties, as well as methods for selecting populations of epithelial stem cells, should give us the necessary tools to overcome the difficulties that constrain human hair follicle neogenesis.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4444612/
Another study looking at actually healing wounds (grafting, combinding human and rodent cells and tissues in a variety of different ways) in general but obviously looked at regenerating hair follicles expressed the same challenge about culturing papilla cells and maintaining the inductive properties which are shown to be capable of regenerating hair follicles (I know Tsuji is extracting papilla cells, and as the citation shows from the 2010 study it is rectified in 3-D dermal spears more a kin to the actual structure of living tissue, something Tsuji and their team are utilizing):
During embryogenesis, mesenchymal cells signal the overlying epithelium to induce HF formation, and in adults a specialized group of mesenchymal cells, the dermal papilla (DP) cells, have been shown to retain the capacity to induce HF regeneration (
Hardy 1992,
Reddy et al., 2001,
Gharzi et al., 2003). DP cells from rodents induce HFs in a variety of assays (reviewed in
Ohyama et al., 2010), but it has been difficult to grow human DP cells that maintain inductive capacity in culture (
Higgins et al., 2010). Recent technological advances have enabled the use of human cells to form chimeric HFs, for example by combining human keratinocytes and rodent mesenchymal cells in chamber assays (
Ehama et al. 2007), human scalp dermal papilla cells and mouse epidermal keratinocytes in flap grafts (
Qiao et al., 2009) or injecting human DP cells, grown as spheroids, together with mouse epidermal cells in reconstitution or “patch” assays (
Kang et al., 2012). However, to date, complete and entirely human HFs formed from normal cultured cells have not been reported.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3947143/
Very promising when looking at Dr. Tsuji work we clearly see neogeneration of new hair follicles (after the cultivated cells produce the regenerated hair germ that is implanted):
The hair follicle is the only organ known to regenerate repeatedly after birth (hair cycles*3). In 2012, the research team isolated epithelial stem cells and follicle dermal papilla cells (mesenchymal stem cells)*4from the follicles of mature mouse whiskers and body hair and used them to develop a technology for the regeneration of follicular primordium by utilizing an “organ primordium technology*5” previously developed by the same team. Transplanting the regenerated follicular primordium into hairless mice results in the growth of regenerative follicles, thus demonstrating the feasibility of hair shaft regeneration. The transplanted primordium also forms connections with surrounding tissues (arrector pili muscle and nerves) and repeats normal hair cycles. Furthermore, this method allows control of the hair color by adding pigment stem cells, and the number of hair follicles regenerated, elevating its potential for the aesthetic treatment of alopecia.
https://global.kyocera.com/news/2016/0702_nfid.html
Dr. Tsuji and his team clearly have ( according to their diagrams, and research) begun to address what the researchers in the previous study deemed to be the most challenging part to regenerating or neogenerating human hair follicles “Three-dimensional culture conditions mimicking the structure of living tissue“ That is very promising when you concatenate the studies observations, especially considering that the transplanted “ Primordium/germ” form connections with the surrounding tissue in the animal model. I am a laymen but to me that would be demonstrative of a success in “mimicking the structure of living tissue“. The key here is will the regenerated hair germ respond the same in human models, time will tell, The other thing is fluctuating results between each individual; naturally something that is always a concern and taken into consideration with any kind of new/next generation treatment.
P.S Don’t even get me started on the inadequacies of modern medicine, and the mythopoetic society we live in, that proclaims we have so much advancements in modern medicine, addressing a wide variety of ailments. Miniature organs have been regenerated in vitro, A heart, a kidney, a penis, even a mini brain, etc. but this is just the very very early onset, glimmering hope that may be borderline delusional. I can only imagine what it will take to actually cultivate a functioning heart using a patient’s own cells therefore making the organ autologous, greatly reducing the risk of rejection. I have no right to speculate I’m not qualified, but even repairing 2 cm of spinal tissue is decades away to potentially not possible ( when looking at chronic injuries, which would require axons to re-sprout all throughout the body, there is more hope for acute injuries obviously), so functioning autologous organ is ready for transplant… I believe genetic therapies will become more viable before cellular biologist reach such heights, or more realistically develop cellular therapies that can repair any cardiomyopathy, that is much more realistic for the coming decades.