Evaluation of Tissue Regeneration Potential (in the Skin) of Child's Adipose Cells During the Development.

Through this study, the medium term objective is to approach a clinical protocol for treatment of pathological scars in developing an appropriate way to deliver ADSC for a future clinical application, while ensuring the safety of such procedure.

The primary goal of this work is to determine whether ADSC from children prepared according to Good Manufacturing Practice (GMP), is associated with an improvement of wound healing in vivo as demonstrated with adult ADSC. To answer this question, 40 samples of adipose tissue of children obtained from settled surgery (inguinal hernia and vesico-ureteral reflux by suprapubic way) will be performed within the 2 groups of children; 0 to 1 year and 2 to 13 years, defined from data acquired in the previous protocol. Wound healing will be evaluated in a nude mouse model of skin burn. A macroscopic analysis will be carried out with two indexes described in the literature (re-epithelialization and scar contraction) and expressed as a percentage of the initial lesion at different times (3 days, 7 days, 10 days, 14 days, 21 days, 30 days). A microscopic analysis will be conducted to determine the rate of re-epithelialization (day 7) and the evolution of the skin structural parameters (dermal and epidermal thickness, density of collagen, inflammatory infiltration). These indexes will be defined in the treated group (burned mice and injected with pediatric ADSC) from control mice (burned but not injected with cells). A comparative analysis between the two groups of age will be conducted that will be also compared to data collected with adult ADSC.

To answer to the second part of this primary goal regarding to safety, the study will perform a long-term follow-up (1 yr) of burned mice injected with of ADSC, to obtain data in the animal after transplantation of cells and for further clinical study.

Complementary in vitro investigations still seems necessary to better understand the specificities of ADSC from pediatric origin and particularly to perform transcriptomic and epigenetic studies.