Discussion
HSA-SeNPs have more anti-photoaging effects on the skin than SeNPs, including the protective effects on skin cell proliferation, cell survival, and structure under photoaging conditions. HSA-SeNPs can be used to protect skin from photoaging and repair skin injury caused by UVB exposure.
Methods
HSA-SeNPs were prepared by self-assembling denatured human serum albumin and inorganic selenite. The cytotoxicity of HSA-SeNPs was assessed using the MTT method. Cell survival and proliferation rates were tested to observe the protective effect of HSA-SeNPs on human skin keratinocytes against photoaging. Simultaneously, ICR mice were used for animal experiments. H&E and Masson trichromatic staining were employed to observe morphological changes in skin structure and collagen fiber disorders after UVB irradiation. Quantitative RT-PCR was utilized to measure changes in mRNA expression levels of factors related to collagen metabolism, inflammation, oxidative stress regulation, and senescence markers.
Results
The HSA-SeNPs group exhibited significantly higher survival and proliferation rates of UVB-irradiated keratinocytes than the control group. Following UVB irradiation, the back skin of ICR mice displayed severe sunburn with disrupted collagen fibers. However, HSA-SeNPs demonstrated superior efficacy in alleviating these symptoms compared to SeNPs alone. In a UVB-irradiated mice model, mRNA expression of collagen type I and III was dysregulated while MMP1, inflammatory factors, and p21 mRNA expression were upregulated; concurrently Nrf2 and Gpx1 mRNA expression were downregulated. In contrast, HSA-SeNPs maintained the mRNA expression of those factors to be stable In addition, the level of SOD decreased, and MDA elevated significantly in the skin after UVB irradiation, but no significant differences in SOD and MDA levels between the HSA-SeNPs group with UVB irradiation and the UVB-free untreated group.