There are various methods which enable to evaluate anti-pollutant efficacy on cell supports, skin model or skin 3Dprint using many biomarker analyses: Cell Proliferation, Lipid metabolism, Carbonylated proteins, Antioxidant defences markers, DNA damage, various Proteins (barrier function, pigmentation or mitochondrial), Inflammation mediators, or Protease activity.
To address the needs for anti-pollution claims substantiation, the major CROs also developed specific in-vitro and ex-vivo protocols that objectively evaluate skin exposure to several pollutants. These assays represent an ethical alternative to human testing when induced stresses are harmful: pollution, UV… They can demonstrate the effects in preventing pollutants from adhering to the skin surface, removing pollutants from the skin or in reducing their oxidative impact.
Beyond the duration of use that everybody would like longer and longer, 3D skin models, epidermis, or full thickness – bioprint or not – and ex vivo testing present undeniable benefits for the anti-pollution evaluation through:
– The standardized assay conditions
– The various end points and their combination of assays
– The choice of various analytical methods : Proteic and metabolic methods, Morphology and imaging methods, Gene expression, multi-omics approach, …
– Quantitative and illustrative results.
Several types of pollution stress can be applied, either directly in the cell culture media or by spraying the pollutant on the assay support or in a chamber: Blue-light (400 – 470 nm), UVA, UVB, Infrared, cigarette smoke, ozone, heavy metals, volatile organic compounds, PM 2.5, particulate matters, inflammation mediators.
The main biomarkers that are quantified are numerous: Cell Proliferation, lipid metabolism, Carbonylated proteins, antioxidant defence markers, DNA damage, various proteins (barrier function, pigmentation or mitochondrial), inflammation mediators, or protease activity. The choice of the test models depends mainly on the studied mechanism of action.
A few questions remain, how can the anti-pollution testing evolve?
For efficacy objectivation, in-vitro and ex-vivo methods often represent quicker, cheaper and a reliable proof of concept as predictors of efficacy in humans. The combination of the 3 pillars of the assay design among the selection of the biomarkers, the analytical methods and the assay supports making the in-vitro testing a source of constant innovation for the beauty industry. The preliminary discussions with each in vitro CRO’s to design the protocol to answer the aim of the study is crucial to select the best analyses adapted to the searched biomarkers.
