The hair follicle surrounds the human hair root, a bulbous thickening in the human dermis. It forms the root sheath. The hair follicle contains a sebaceous gland to lubricate the hair. It also has numerous sensory nerve endings which register sensations and release the neurotransmitters histamine and serotonin in response to touch ^(*).

Inflammation of the hair follicles can be painful and lead to serious illnesses. They are often difficult to treat because bacteria nestle in the gap between the hair and skin, where it is difficult for active substances to reach them. In order to successfully develop new active substances against hair follicle inflammation, new models are required that can simulate the physiological conditions of the skin as realistically as possible in the laboratory.



Schematic cross-section through the skin with a hair follicle.
Schematic: Wong, D.J. and Chang, H.Y., Wikipedia CC BY 3.0

In order to study hair follicle inflammation more closely in the laboratory, the HIPS researchers, led by Prof. Claus-Michael Lehr, have developed an in vitro model of the human hair follicle. Living human hair follicles were transplanted into a collagen matrix within a 3D-printed polymer scaffold that mimics the microenvironment of the follicle. An antibiotic encapsulated in lipid nanocarriers was able to penetrate the follicle and reduce Staphylococcus aureas bacteria.

The team presented the model in the journal ACS Biomaterials Science & Engineering:
Samy Aliyazdi, Sarah Frisch, Tobias Neu, Barbara Veldung, Pankaj Karande, Ulrich F Schaefer, Brigitta Loretz, Thomas Vogt, Claus-Michael Lehr (2024). A Novel 3D Printed Model of Infected Human Hair Follicles to Demonstrate Targeted Delivery of Nanoantibiotics. ACS Biomaterials Science & Engineering. DOI: 10.1021/acsbiomaterials.4c00570 https://dx.doi.org/10.1021/acsbiomaterials.4c00570

Further information here:
https://www.helmholtz-hzi.de/media-center/newsroom/news-detailseite/haarfollikel-modelle-aus-dem-3d-drucker

Additional information:
(*) https://www.scinexx.de/news/medizin/wie-wir-ueber-unsere-haare-beruehrungen-spueren/dem-3d-drucker