This study investigates the complex process of hair aging, particularly focusing on cellular senescence, a key hallmark of aging, triggered by environmental factors such as UV radiation and pollution. We aimed to induce cellular senescence by causing DNA damage in hair follicle (HF) cultures ex vivo using BrdU treatment. BrdU significantly increased DNA damage and cellular senescence markers, which, in turn, led to a noticeable decline in hair shaft quality demonstrated by reduced hair shaft keratin production. Functionally, this BrdU-induced cellular senescence resulted in a shortened hair growth phase and decreased proliferation of hair matrix keratinocytes. These preliminary findings provide valuable insights into senescence-induced HF aging and may pave the way for targeted cosmetic interventions to promote hair health and longevity.

Short Synopsis for Website/Promotion This presentation showcases a novel integrative model for evaluating hair fibre repair and restoration, bridging cosmetic efficacy with molecular integrity. Through biochemical markers such as protein carbonylation and lipid restoration, the study quantifies structural recovery in hair exposed to chemical and environmental stressors. These objective molecular results align with global sensory evaluations, capturing perceptible improvements in hair condition—both in professional salon treatments and at-home use. By connecting deep biological repair with tangible, real-world benefits, this approach establishes a new scientific standard for validating haircare efficacy across consumer and professional applications.

Titanium dioxide (TiO₂) is an inorganic sunscreen filter found in many mineral-based sunscreens, providing broad spectrum UV protection with a greater affinity for UVB. It is therefore an active ingredient which can be optimised and employed to protect against photoaging. In this presentation, titanium dioxide of different particle sizes, in oil dispersions, will be discussed in terms of blocking various wavelengths of the solar spectrum and alleviating UV-induced expression of various photoaging-associated genes. The talk will draw from previous RNAseq findings in a paper published in last month's issue of The FASEB Journal.