Figure 1. Effect of hyaluronan on HCE cell viability after UVB exposure. HCE cells were incubated with PBS (clear square) or HMW-HA (black square) and irradiated with various doses (0, 25, 75, 150, and 200 mJ/cm²) of UVB. Cell viability was determined by neutral red uptake assay 24 h after irradiation. Data are mean±SD of nine independent experiments. Differences were significant at p<0.05 (one asterisk), p<0.01 (two asterisks), and p<0.001 (three asterisks) compared to the PBS group of each UVB dose.