The interactions of PAMAM-NH2 G4 dendrimer with selected natural amino acids (Gly, Ala, Val, Leu, Ile, Phe, Ser, Thr, Met, Asn, Gln, Pro and Trp) in aqueous solutions were measured with the use of the techniques of calorimetric titration and dilution calorimetry. The results of calorimetric measurements show strong interactions between PAMAM-NH2 G4 dendrimer and amino acids with polar substituents. A macromolecule of PAMAM-NH2 G4 dendrimer can coordinate 20 to 40 molecules of amino acid. (C) 2013 Elsevier Ltd. All rights reserved.