OBJECTIVE To analyze the optimal structures of five Pt (IV) anticancer complexes, and study the kinetics and mechanism of
the uptake of these complexes by human erythrocytes. METHODS The optimal structures of five Pt (IV) anticancer complexes were calculated using simulation method of molecular modeling. The first-order rate constants of their
cellular uptake were measured. The interaction of the complexes with human erythrocytes was discussed based on the change of mercapto-groups contents in membrane proteins and intrinsic fluorescence of membrane proteins. RESULTS These complexes entered human erythrocytes by way of simple passive diffusion, and the first-order rate constants of their cellular uptake were obtained. There were a litter change of mercapto-groups contents in membrane proteins in the process of interaction of the complexes with human erythrocytes membrane, but the intrinsic fluorescence of membrane proteins was changed. CONCLUSION Four complexes entered human erythrocytes by process of first-order kinetics of simple passive diffusion, but their rate constants are not same. The uptake process of the complex JM221 by the human erythrocytes does not follow first-order kinetics. The conformation changes of membrane proteins may have occurred due to the weak interaction of the complexes with membrane.