Stefan Nehrer

Blood-derived products, such as citrate platelet-rich plasma (CPRP) and hyperacute serum (HAS), are recognized for their rich growth factor content. When human dermal fibroblast (HDF) cells are exposed to combined mitogenic and DNA-damaging stimuli, it can lead to an increased burden of senescent cells and a modified senescence-associated secretory phenotype. In this study, the senescent state was comprehensively assessed through various methods, including phosphorylated histone H2AX (γH2AX) staining, p21 and p16 q-PCR, p21-western blot, growth curves, and senescence-associated ß-galactosidase staining. Two primary treatments with blood products were administered, one early (immediately after etoposide) and the other late (11 days after etoposide treatment). The effects of the blood product treatment were evaluated by measuring interleukin 6 and 8 (IL-6 and IL-8) levels, as well as collagen 1 (COL1) and p21 mRNA expression. Additionally, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assays, cell size measurements, viability assays, and cell number calculations were conducted. The results revealed that cells treated with hyperacute serum in the early treatment phase exhibited the lowest observed IL-6 and IL-8 levels. In contrast, a clear inflammatory response for IL-8 was observed in cells treated with hyperacute serum and citrate platelet-rich plasma during the late treatment. Furthermore, an upregulation of COL1 expression was observed in the early treatment, while cells in the late treatment group remained unaffected. Notably, citrate platelet-rich plasma-treated cells showed a decrease in COL1 expression. Overall, the treatment with blood products appears to have slightly positive effects on skin rejuvenation.