Using atomic force microscope to investigate the influence of UVB radiation on cell behaviour and elasticity of dermal fibroblasts

The aim of this research is using different doses of UVB radiation to study the influence on the cell behaviour and elasticity of Hs68 human dermal fibroblasts. These studies include cell viability analysis, proliferation index, gene expression and Young's modulus measurement using atomic force microscope (AFM). Results have exhibited that the cell viability was 100%, 89.46%, 73.76% and 70.75% when the exposed dose of UVB radiation on dermal fibroblasts was 0, 540, 1080 and 2160 mJ/cm². After 24 h of incubation, dermal fibroblasts without exposure to UVB radiation increased the index of cell numbers to 183.5% but cells exposed to UVB radiation between 216 and 2160 mJ/cm² reduced cell growth to 131% and 47.7%. Moreover, Young's modulus of Hs68 dermal fibroblasts measured by AFM ranged from 24.12 kPa to 9.40 kPa depending on the UVB exposed dose (0-2160 mJ/cm²). Hs68 human dermal fibroblasts after UVB irradiation showed dose–dependently inhibition on the gene expression of type 1 collagen and elastin and that may be related to the reduction of cell elasticity. Therefore, UVB radiation has showed a dose–dependent inhibitory effect on cell viability, proliferation, gene expression and Young's modulus and AFM is a useful tool in nano–scale to analyse cell elasticity.