CTIBIOTECH, Anne-France de Bengy, Nico Forraz, Aurélie Pagnon-Minot, Colin McGuckin (France)

Governments are increasing regulations for products destined for use on newborns and babies in recent years, not least because of scandals of children being hurt with bad ingredient production, malpractice, but also incompatibility with adult products. The epidermis and stratum corneum of baby skin can be 30% or less of an adult skin sample [1], yet many products destined for children continue to be tested on adult skin or diluted forms.

Generally, the terms “baby” or “infant” define young children less than 1 year old and sometimes it might be extended until 2 years old, whereas the terms “newborn” or “neonate” refer to the first month of life [2]. Following birth, the dry, gaseous environment induces maturational changes to the air-exposed surfaces of the baby and in particular the epidermal barrier, allowing a progressively more functionalized and protecting skin development, [1, 2]. Nevertheless, baby skin differs from mature adult skin in structure, function and composition and still continues to mature through the first year of life [1].

Thus, baby skin should be considered as more fragile and sensitive than adult skin, in particular for premature babies whose skin maturation takes longer [1]. Hence, special consideration for various creams or cosmetic products used for babies is necessary and specific baby skin models appear more relevant than adult models to test their real impact on baby skin, in particular for newborns. Developing appropriate and accurate models of infants is not an easy task. Ethically it is not acceptable to take tissue from newborn babies without either a diagnostic or treatment reason.

In vitro tests have been developed using foreskin samples but size, age and sex are a limitation. Keratinocytes and fibroblast models in 2D or 3D reconstructed models are also used, but human tissue access is difficult from infants and has severe limitations in truly mimicking the skin tissue environment, which has also neural, immune, matrix and endothelial components not well reconstructed artificially. To our knowledge, no valid reconstructed full baby skin model has been designed to date. Having worked, for therapeutic reasons, for many years on tissues linked to birth but usually discarded (umbilical cord, Wharton jelly, cord blood and placenta) [3 – 6], we realized the high stem cell potential of those tissues might be appropriate to obtain a baby skin model allowing ethical investigation into newborns and infants.

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Published by IFSCC Magazine