Fig. 3

Cytotoxicity of CuS NPs toward normal and senescent chondrocytes. (a, b) Cell viability of normal chondrocytes co-cultured with CuS and B2M-CuS NPs at various concentrations for 24 h. (c) Cell viability of senescent chondrocytes co-cultured with CuS or B2M-CuS NPs (50 µg mL^− 1) for 24 h. Live/dead staining of normal chondrocytes (d) and senescent chondrocytes (e) co-cultured with CuS NPs or B2M-CuS NPs (50 µg mL^− 1) for 24 h. Data are presented as mean ± SD (n = 3). *p<0.05, **p<0.01, ***p<0.001, and ****p<0.0001