preprints.org > medicine and pharmacology > dermatology > doi: 10.20944/preprints202407.1671.v1 (registering DOI)

Preprint Article Version 1 This version is not peer-reviewed

Version 1 : Received: 19 July 2024 / Approved: 22 July 2024 / Online: 22 July 2024 (07:23:17 CEST)

Introduction This study was conducted to validate the findings of a prior study published in JDD in September 2023, which reported that a topical firming and toning body lotion (FTB – SkinMedica®, Allergan Aesthetics, an AbbVie Company, Irvine, CA) upregulated several genes in a UV irradiated 3D full-thickness human skin model, outperforming other products, including TransFORM Body Treatment with TriHex Technology® (ATF – Alastin Skincare®, a Galderma company Fort Worth, Texas, USA ). Given the unique response reported for FTB, we conducted this study to assess the reproducibility of these results and explore gene expression at multiple time points, along with validating protein expression in an ex vivo model. Materials and Methods Experiments were conducted using an ex vivo model with photodamaged skin from facelift patients, under an Institutional Review Board approved study. Skin samples were processed, cultured in transwells with Skin Media, and treated daily with either TransFORM or FTB for 7 days. A control group was left untreated. Gene expression was assessed using RT-PCR on days 1 and 3, immunofluorescence after 3 and 7 days of treatment. Skin samples were fixed, paraffin-embedded, sectioned, and stained with an anti-tropoelastin antibody. Fluorescence detection and imaging were conducted to assess protein expression changes. Results Gene expression data from our study and the initial study showed a few similarities but multiple discrepancies. In particular, as opposed to results previously reported at only the 24-hour time point, additional time points showed complete reversal of many of these results. For example, COL1A1 expression at 24 hours was similar for FTB in both studies but differed for TransFORM which showed higher levels at 24 hours. However, at day 3, COL1A1 expression decreased markedly for FTB and was sustained for TransFORM. Other genes, such as COL3A1, COL5, ELN, VEGFC, ATG7, ATG12, BECN1, POMP, PSMB5, and PSMB6, exhibited varying expression patterns between the studies and across different time points. From a translational perspective, histological analysis showed that TransFORM enhanced elastin fiber presence in the dermal-epidermal junction (DEJ) more effectively than FTB at both day 3 and day 7. FTB-treated samples maintained a gap in the DEJ, while TransFORM-treated samples exhibited increased cellular proliferation and DEJ undulation, indicative of a healthier regenerative response. Conclusion This study highlights the problems of examining data and drawing conclusions using a single point of examination. In addition, when a study reports positive results for only 1 product among a range of 8 competitive products, further questioning is essential to exclude the possibility of the experimental model favoring that particular product. The additional 3-day timepoint and further translational examination of histological changes, paints a completely different picture to that reported in the prior publication TransFORM outperformed FTB in most gene expression and histological parameters when assessed over multiple time points in a physiologically relevant ex vivo model.

topical body formulation; gene expression; skin tightening

Medicine and Pharmacology, Dermatology

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