Protective impact of nicotinamide mononucleotide (NMN) and platelet-rich fibrin (PRF) on replicative and radiation-induced senescence of human osteoblasts

The aim of this study was to investigate the cellular changes induced by spontaneous/replicative senescence and radiation in human osteoblasts (OBs), and the impact of cultivation with nicotinamide mononucleotide (NMN) and platelet-rich fibrin (PRF) on apoptosis, senescence-associated β-galactosidase staining (SA β-gal), and senescence-related gene expression using RT² Profiler PCR array. The results showed that replicative OB aging follows a different pattern from that of radiation-induced cellular senescence. SA β-gal intensity score showed a significant elevation after spontaneous replicative aging of OB (agiT1) 7 days following the start of the experiment, compared with their initial control condition (T0) (T0 = 2.1 ± 0.47; agiT1 = 9.60 ± 1.56; p = 0.001). Concurrent treatment by NMN and PRF showed a protective effect on OBs undergoing replicative senescence, and reduced SA β-gal staining significantly (agiT1 = 9.60 ± 1.56; agiT1+PRF = 3.19 ± 0.52; agiT1+NMN = 3.38 ± 0.36; p < 0.001). These results provide evidence for the potential clinical implications of systematic NMN administration and local PRF application to prevent age-related bone disturbances in elderly patients.