Effects of PC AuNP on the production of 2β-OH TST (a, b), 6β-OH TST (c, d) and 15β-OH TST (e, f) in pHLM. Data represent mean ± S.D. (n=3). IC50, half maximal inhibitory conc.; pHLM, pooled human liver microsomes; ND, not determined by fitting a Hill equation with variable slope to the observed data using GraphPad Prism®; PC, human plasma protein corona; BPEI, branched polyethylenimine; LA, lipoic acid; PEG, polyethylene glycol; Conc, concentration; 2β-OH TST, 2β-hydroxytestosterone; 6β-OH TST, 6β-hydroxytestosterone; 15β-OH TST, 15β-hydroxytestosterone.