Growth factors‐based platelet lysate rejuvenates skin against ageing through NF‐κB signalling pathway: In vitro and in vivo mechanistic and clinical studies

Platelets benefit tissue regeneration by secreting growth factors, and platelet products, for example, platelet lysate (PL), have been clinically applied for tissue rejuvenation. To determine the anti-ageing efficacy and mechanism of human PL (hPL) on skin, this study conducted clinical retrospective analysis, nude mice-based in vivo study and human dermal fibroblasts (HDFs)-based in vitro study.Flow cytometry was employed for quality control of hPL, and ELISA was used for quantification of growth factors (EGF, IGF-1, PDGF and TGF-β) in hPL. After d-galactose modelling, skin texture grading, histopathological observation, immunofluorescence analysis and oxidative stress assays were conducted on nude mice, while SA-β-gal staining, CCK-8 and wound healing assays were conducted on HDFs. qPCR and western blot were conducted to clarify hPL's mechanism.The clinical retrospective data showed that hPL obviously rejuvenated human skin appearances without adverse events. The animal data showed that hPL exerted rejuvenative effects on skin, and the cellular data showed that hPL significantly promoted the proliferation and migration of HDFs and suppressed senescence-associated secretory protein secretion and senescence state of senescent HDFs by suppressing NF-κB pathway. The NF-κB-dependent mechanism was verified positively by using P65 siRNA and negatively by using prostratin. Furthermore, EGF, IGF-1, PDGF and TGF-β were found as the main ingredients in hPL, which contributed to the efficacy and mechanism of hPL.This study provided novel knowledge of hPL, making it ideal for skin rejuvenation.