Such an uptake can be not only selective, but also can preserve the activity and secondary structure of proteins, which is necessary for potential applications in drug delivery or peptide therapy. In addition, sequestration of proteins by coacervates can be regulated by change of pH or mixing ratio of polyelectrolytes. Generally, it seems to be clear that electrostatic interactions play a key role in the partitioning whereas hydrophobicity or other specific interactions fine-tune the behavior while the liquid nature of both phases ensures that the whole system remains close to thermodynamic equilibrium.