Determination of proliferation and collagen synthesis of human dermal hair papilla cells

The study explored the role of dermal papillae in hair growth using in vitro cultures. It was found that outer root sheath cells (ORSCs) grew more actively when cultured with dermal papillae, suggesting the presence of papilla-derived factors that stimulate ORSC growth. Additionally, epithelial cells from the bulb matrix grew towards implanted dermal papillae, indicating that dermal papillae might produce factors that attract these cells. When the dermal papilla remained attached to the hair bulb matrix, hair and follicle elongation continued for over a week. However, detachment or damage to the papilla-matrix junction suppressed hair and follicle growth, highlighting the importance of this attachment for normal development.

The study investigated the co-culture of human hair follicles and dermal papillae in a collagen matrix. It was found that when hair follicles were cultured alone, outer root sheath cells formed spike-like structures. However, when dermal papillae were present, these spikes grew earlier and more rapidly, suggesting that dermal papilla cells produce factors that enhance and attract follicular epithelial cell growth. In cultures where the dermal papilla was removed, epithelial cells still formed spikes, but the presence of the papilla directed their growth towards it. The study concluded that the attachment of the dermal papilla to the hair bulb matrix is crucial for normal hair and follicle growth, and the model could be useful for studying hair growth and follicle interactions in vitro.