Category Archives: Stem Cells

Dr. Pietro Gentile, Hair Follicle Stem Cells and PRP

Over the past few years, I have heard a lot about Dr. Pietro Gentile of Italy and his unique work in the hair loss field. His website and his Instagram have some interesting content. However, both are lacking relative to the higher quality of his numerous research papers.

Dr. Pietro Gentile and PRP

I originally learnt about Dr. Gentile via his collaboration with Dr. John Cole and Chiara Insalaco. In 2017, the three of them authored a paper comparing non-activated PRP versus activated PRP.

In my detailed post on the effectiveness of PRP for hair loss, I listed around 40 studies at the bottom. Of that total, 5 were authored by Dr. Gentile. On his website, the doctor has several pages devoted to PRP for hair loss and PRP for facial cosmetic treatments.

Hair Follicle Stem Cells

Micrograft Stem Cell Transplant Hair Growth Before After -- Pietro Gentile
Micrograft Stem Cell Hair Transplant Before and After in a 38-year old Female. Copyright © 2020 Pietro Gentile et al.

More interestingly, Dr. Pietro Gentile has in recent years published a number of papers on stem cells and hair growth. Most recently, in January 2020, he authored a paper titled “Autologous Micrografts from Scalp Tissue“. The conclusion was that micrografts containing autologous human hair follicle mesenchymal stem cells (HF-MSCs) could represent a safe and viable hair loss treatment.

The autologous micrografts of HFSCs were prepared using the doctor’s proprietary “Gentile Protocol”. Instead of harvesting hair follicle grafts like in a hair transplant, this process entails harvesting scalp tissue and associated hair follicle stem cells. I think that this tissue extraction can also be from outside the typical permanent hair donor zone. Dr. Gentile published the outline of his hair follicle stem cell isolation technique in an earlier paper from 2017.

Autologous Micrografts of Hair Follicle Stem Cells
Autologous Micrograft Injections of Hair Follicle Stem Cells (HFSCs) in a 41-year old Male with Androgenetic Alopecia. Before and After (58 Weeks). Copyright © 2020 Pietro Gentile et al.

Other Findings

in 2019, Dr. Gentile published a study on Adipose Tissue-Derived Hair Follicle Stem Cells (HD-AFSCs) improving hair growth and density. Make sure to read my past posts on adipose stem cells and hair growth. The doctor has also published a number of papers in the past on stromal vascular fraction, especially in regenerative plastic surgery and scar reduction applications.

In 2020, Dr. Gentile and his team found that a combination PRP + Microneedling + Laser treatment protocol led to great hair growth results. However, hard to tell which of the three made the most impact.

Hair-Bearing Skin Generated from Pluripotent Stem Cells

Update: January 18, 2022 — Dr. Karl Koehler is covered in detail in the second half of a new article in MIT Technology Review.

“I think people will go pretty far to get their hair back. But at first it will be a bespoke process and very costly.”

Update: The podcast for the below news is here.

Pluripotent Stem Cells and Hair Growth

Yesterday a very important study was published in Nature Magazine. It is titled “Hair-bearing human skin generated entirely from pluripotent stem cells”. The scientists behind this research took 6 years to complete and publish their work.

The study has numerous co-authors from a few medical centers and universities based in the US. The lead author is Dr. Jiyoon Lee, while the correspondence author is Dr. Karl Koehler. The latter works at Boston Children’s Hospital as well as Harvard Medical School. Moreover, Dr. Koehler’s lab has its own site, on which he published a post about these findings.

Dr. Karl Koehler via Twitter

Pluripotent Stem Cells to Grow Hair
Pluripotent Stem Cells to Grow Hair. From Dr. Karl Koehler’s Twitter feed.

From Skin Organoids to Hair

In this latest research, undifferentiated human stem cells were successfully coaxed into developing skin-like organoids in vitro. When these human-derived structures were grafted onto immuno-compromised bald mice, the rodents produced robust (albeit shorter length) hair.

Note that in 2015, Dr. Alexey Terskikh and his team used pluripotent stem cells from humans to create dermal papilla type cells. These were then injected into hairless mice and grew hair.

Pluripotent Stem Cells Hair Growth
Pluripotent Stem Cells and Hair Growth — Nature Magazine.

In this new work, the scientists generated near-complete skin organoids first that ultimately resulted in pigmented hair. The skin cells grew in a sphere and were “fed” with various chemicals and growth factors (such as BMP4 and FGF2) for 4-5 months. Both the dermis and epidermis skin layers were grown successfully.

If this work goes through successful clinical trials, it will essentially mean a cure for hair loss. Nevertheless, the global media has largely ignored this research, with the UK’s Mirror being a notable exception. And as always, the Daily Mail too.

Cotsarelis Rises Again

Prolific blog commentator “MJones”‘ favorite hair loss researcher and fellow Alexander the Great progeny Dr. George Cotsarelis has been missing in action of late. However, this new research is so significant, that Dr. Cotsarelis and Dr. Leo Wang wrote a detailed article summarizing it in Nature Magazine.

Per the two doctors, this study represents a major step towards a cure for baldness in humans. They are confident that this research will eventually see its promise realized. This technique makes it possible to produce human hair without having to take any donor hair from the human.

Moreover, individuals who have major wounds, scars and genetic skin diseases will all benefit from revolutionary new treatments based on this research. That is if it comes to clinic of course.

In these times of pandemics, protests and riots, it is great to see Dr. Cotsarelis’ still unabated optimism. Ironically, for “MJones”, the glass has always been half empty.

Further reading: An excellent 2019 paper summarizing tissue engineering strategies for human hair follicle regeneration.