509 Ultrasmall prussian blue nanoparticles protect human skin fibroblasts from ultraviolet A stress induced premature senescence

Abstract

Background: Skin aging is one of the major challenges our society faces, and the generation of reactive oxygen species(ROS)seems to play a major role in age-related skin modifications.Thus, ROS scavengers that can block excessive production of ROS have great therapeutic potential. Ultrasmall prussian blue nanoparticles(USPBNPs),which belong to the iron-based metal-organic frameworks, exhibited an intensive ability of scavenging free radicals as nanozyme and showed great application potential in the treatment of free radical-related diseases. Herein, we propose an efficient treatment strategy in which an artificial nanozyme with multienzyme activity drives photoprotection against ultraviolet A stress induced premature senescence(UVA-SIPS) primarily by scavenging ROS. Methods: In the present study, UVA-SIPS model was established by UVA radiation on human skin fibroblasts .Cell viability was determined using the Cell Counting Kit-8 (CCK-8). Senescent cells were detected by senescence β-galactosidase staining.Fluorescence microscopy and flow cytometry were used to assay the intracellular ROS concentration.Cell cycle was measured by flow cytometry.The expression of cellular γH2A.X,p16,p21 and p53 were also measured. Results: The results revealed that UVA radiation could cause premature senescence in human skin fibroblasts. Interestingly, the pretreatment of USPBNPs significantly reduced senescent cells and attenuated several features of cellular senescence, including morphological and metabolic changes,senescence related DNA damage, cell cycle arrest and more senescence-associated secretory phenotypes (SASPs). Conclusions: This study provides a proof of concept for a novel class of protective nanoagents that might be beneficial for prevention of skin photoaging and other age-related disorders.