Every day, skin and hair are subjected to many stress and environmental factors such as pollution, heat, radiation (UV, infrared, etc.), chemical products or microorganisms (bacteria, yeasts, etc.). As these external aggressions are considered as factors of oxidative stress, inflammation or DNA damages, they can alter skin quality, increase skin sensitivity and lead to premature ageing.
To fight these aggressions, the skin has innate defense and protection mechanisms, on which an active ingredient or cosmetic compound can have an effect: pH, commensal flora, sebum, antimicrobial substances, antioxidant enzymes, detoxification enzymes, immune cells, etc.
Skin protection and defense: in vitro models and assays
Bioalternatives has many in vitro or ex vivo models at your disposal:
- normal human epidermal keratinocytes (NHEK)
- normal human dermal fibroblasts (NHDF)
- reconstructed human epidermis (RHE)
- normal, photo-aged and deficient human full thickness reconstructed skin (FTSK)
- skin explants (ex vivo)
on which we can evaluate the protective effect of active ingredients or formulations on:
- infrared, UVB, UVB+(A) radiation
- free radicals
- pollution (urban dust, indoor dust, cigarette smoke, etc.)
- chemical stress (PMA, SDS, etc.)
- microorganisms (bacteria, yeasts, viruses, etc.) or pathogen-associated molecular patterns (TLR agonists, etc.)
- osmotic stress, thermal stress, etc.
- nutrient deficiency
by measuring (for example):
- cell viability or metabolism
- inflammatory mediator release (IL-8, PGE2, IL-6, TNF-alpha, etc.)
- free radical production
- DNA damages (CPD, sunburn cells, comet assay, etc.)
- metalloproteinase expression or production
- antimicrobial peptide production (beta-defensins, S100A7, etc.)
Here are a few examples among all assays proposed by Bioalternatives in the field of skin protection and defense:
Skin protection and defense: clinical bioanalysis
Analysis of markers of oxidative stress and inflammation
Our company has developed ready-to-use non-invasive collection kits to analyze the lipids and biomarkers of the skin surface from your samples or from those of your clinical center.
Oxidative stress and inflammation markers are analyzed from samples using the SW Kit. The sampling areas depend on the type of stress (induced stress or external environment).
The analyzed markers are:
- products from peroxidation and lipid detoxification (MDA, peroxidized squalene, CAT, SOD, etc.)
- protein oxidation products (AOPP Dityrosin, ROH, etc.)
- markers of inflammation (cytokines, cascade of fatty acids, PGE2)
These evaluations help support your claims about the efficacy of anti-pollution products, protective products , anti-aging products, etc. .
Screening of inflammation markers
Contaminant analysis by Scanning Electron Microscopy (SEM)
Our company offers to evaluate the cleaning and protective effect of products by scanning electron microscopy. Observations have been made on reconstructed human epidermis subjected to pollutants and observed before and after application of the cleaning product.
RHE subject to contaminants before and after cleaning – SEM X 70