Branched dextran-graft-polyacrylamide copolymers with different surface properties (charged and uncharged, pure and loaded by Ag or Au nanoparticles) were created in order to drug delivery usage. By means of differential scanning calorimetry, membranotropic action of the polymers was revealed in a set of model lipid membranes, both charged and uncharged. It was observed that negatively charged membranes were more sensitive to the polymers introduction then uncharged one. The most pronounced membrantoropic effects resulted from membrane surface disturbance, which is due to significant contribution and specificity of surface interaction in the systems studied.