Sebum is a complex lipids mixture secreted by sebocytes and deposited in stratum corneum for helping to the skin barrier function. Disruption of sebum production leads to common skin diseases, including acne or atopic dermatitis; it also contributes to the development of oily or dry skin and impacts both appearance and beauty of the skin. Solutions to develop more efficient sebum-regulating cosmetics still require more predictive testing ranging from lab data to humans. Success of lab-to-donor data is not easy and quite often fails because of no proper translational readouts.

Therefore, Gattefossé and CTIBiotech have joined forces to develop a relevant 3D bio printed model integrating sebocytes for measuring non-invasive parameters in vitro as on real humans while at the same time giving laboratory readouts.

Real-time monitoring of sebum production

Using connected scales, Gattefossé and CTIBiotech used bioimpedance [1] to evaluate changes in the local environment of a 3D skin model integrating sebocytes. Measurement of such a non-invasive electrical activity allowed the scientists to follow in real-time the sebum production, in addition to laboratory readouts dealing with cellular, matrix and tissue development.

“Full thickness skin models containing sebocytes have reproducible oil production which is increased by linoleic acid and reduced by TOFA, and remarkably this is characterized by significant changes in bioimpedance in both printed tissues and culture supernatants surrounding them. Bioimpedance, linked to the sebum production thus proves to be an in vitro non-invasive proper parameter and measurable in real-time, to design ever more predictive and effective testing, since 3D models described here and linked with a simple chip system, accurately mirror changes within skin models as on live donors,” says Dr. Nicolas Bechetoille, Ph.D/HDR, Research Manager Skin Biology, Head of Biology Laboratory at Gattefossé.

While the use of bio-impedance to monitor sebum production by the skin is a natural advance, Professor Colin McGuckin, President and Chief Scientific Officer at CTIBiotech highlights that the real innovation comes from developing real-time analysis for oil changes.

“We advanced our 3D printed full thickness skin models with an integrated bioimpedance chip connected to monitor changes. Linking cosmetics screening in this way advances faster towards human tests and increases our ability to make more effective products,” he says.

This work will be presented at the 32nd IFSCC Congress in London, 19-22 September 2022.