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Article by Sabrina Madiedo-Podvrsan & Roberta Lock
Growing Hair in the Lab Within Days
Source Publication:
In vitro hair follicle growth model for drug testing, Scientific Reports 2023
Kageyama et al., Junji Fukuda Lab.
While hair loss notably impacts psychosocial well-being by altering physical appearance, its effects reach beyond aesthetics and also influence crucial physiological functions, including temperature regulation, distribution of sebum and sweat, and sensory perception and tactile activity. While medications represent the predominant non-invasive treatment option for hair loss, their effectiveness often falls short of expectations, and a major hurdle for screening new drugs is their reliance on freshly isolated hair follicles for testing, which have limited commercial availability. Hence, bioengineered hair follicles emerge as a promising alternative.
What did these researchers do?
Hair follicles form through intricate molecular crosstalk between two different cell types (epithelial and mesenchymal stem cells) and their specific spatial organization. They exhibit complex structures composed of a permanent upper segment and a continually renewing lower bulb, responsible for hair growth cycles. In this paper, researchers were able to mimic the early stages of hair sprouting in vitro by imitating part of this dynamic and self-renewing lower segment.
Why is this important?
In vitro hair follicle models have already been developed, but they entail extensive culture periods (exceeding 100 days) and come with high costs. In this study, the researchers advanced experimental methodologies to drastically reduce this timeline to just a couple of days. Implementing a straightforward, cost-effective, and time-efficient approach could be pivotal for high-throughput drug screening or upscaling purposes, ultimately propelling advancements in hair growth drug development and grafts for transplantation as an innovative strategy in hair regenerative medicine.
How did the researchers do this?
Early stages of hair sprouting were induced in vitro by co-culturing the epithelial and mesenchymal stem cells in extracellular matrices, namely Matrigel and collagen I, to encourage their self-assembly into sprouting spheroids. While Matrigel and collagen provide a supportive scaffold for the cells to grow on, low attachment U-shaped well plates were employed to encourage cell aggregation and initiate interactions between the different cell types, which is crucial for hair organogenesis. The adaptability of this morphogenesis protocol to pathological (abnormal) hair sprouting was also explored using cells from a donor diagnosed with androgenetic alopecia, a condition characterized by progressive hair loss. In this context, they observed a shorter elongation of the hair-like organoid, potentially attributable to the pathological state of the cells. These findings lend support to the notion that this methodology has the potential to replicate in vivo observations in vitro, thereby paving the way for tailored personalized treatment options.
Hair sprouting from lab-grown hair follicles within 10 days of culture
What comes next?
While these results are promising, the hair-like sprouting organoids generated in this study do not fully represent mature hair follicles. Further advancements are needed to better mimic the microenvironment surrounding the hair, such as the skin, which could enhance a more complex differentiation. Nonetheless, this approach offers the possibility of creating more test tissues and potentially tailoring them to various hair conditions, thus supporting personalized medicine applications.