AsianScientist (Aug. 23, 2019) – Japanese scientists have devised an efficient method of successfully generating hair growth in nude mice. The method, published in Biomaterials, can be scaled up for clinical applications in human hair regenerative therapy.
Hair loss is currently treated with drugs and hair transplantation, where hair follicles are removed from one part of the body to the site of hair loss. However, these treatment methods have their limitations. Drugs are inefficient at stimulating hair regrowth to the extent necessary to counteract hair loss, and hair transplantation does not increase hair numbers in the scalp.
Previous studies have shown improved results by transplanting, onto the backs of mice, a three-dimensional tissue culture called hair follicle germ (HFG). HFG is composed of hair follicle stem cells derived from both the outer and the deeper connective tissue layers of the skin. However, this approach requires manually merging the stem cells derived from these two different origins under a microscope, making it a challenge to produce the 5,000 or more hair follicle germs (HFGs) required per transplant patient.
To make the method scalable for clinical application, a team of scientists led by Dr. Tatsuto Kageyama and Professor Junji Fukuda at Yokohama National University in Japan fabricated hair beads (HBs) using hair follicle stem cells encapsulated in collagen in U-shaped wells. A suspension of mouse epithelial cells was then added into the wells containing the gel-encapsulated hair beads. After 24 hours, the epithelial cells clumped together in a ball and adhered to the collagen gel. The collagen gel then contracted to form what the researchers called a bead-based hair follicle germ (bbHFG).
To test the efficiency of the hair bead approach, the scientists transplanted HBs and bbHFGs onto the backs of mice. They found that the collagen-enriched hair bead (bbHFG) approach produced a high rate of hair generation four weeks after being transplanted onto the skin of the mice. They also detected high levels of gene expression for almost all the hair producing gene markers in the bbHFGs, suggesting that collagen enrichment and cell aggregation play an important role in promoting hair follicle stem cell development.
The researchers also investigated whether this method could be automated.
“Using an automated spotter, this approach was scalable to prepare a large number of hair follicle germs, which is important for human treatment because thousands of tissue grafts are necessary for a single patient,” Fukuda explained.
The researchers’ next step is to find a way to expand the number of hair follicle stem cells available before preparing tissue grafts. Further studies that use hair follicle stem cells derived from patients suffering from hair loss are also required, Fukuda said.
The article can be found at: Kageyama et al. (2019) Preparation of Hair Beads and Hair Follicle Germs for Regenerative Medicine.
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Source: Yokohama National University; Photo: Pixabay.
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