2009) Monolayers and Langmuir-Blodgett films of amphiphilic tetramethylsulphonatocalix[4]resorcinarene and their interactions with polyethyleneimine and caeruloplasmin, Supramolecular Chemistry, 21:6, 532-538,The paper deals with the surface films of amphiphilic tetramethylsulphonatocalixresorcinarene (R ¼ C 11 H 23 ) 1 insoluble in water but forms rigid stable non-collapsing films at the water -air interface. Compression isotherms were used to investigate the interactions of the macrocycle films with two polymers fed to the aqueous subphases: synthetic -polyethyleneimine (PEI) and natural -an oxidase enzyme caeruloplasmin (CP). The interactions of the surface films of 1 with these substrates are predominantly dictated by the nature of the macromolecules and not by macrocycle interactions with their individual fragments. CP having retained its globular structure was extracted in the layer of 1 and became the dominating component of the film. The synthetic macromolecule of PEI, six times lower in its weight than CP, did not affect the morphology of the interfacial film, involved in the interactions only with its hydrophilic part directed inside the water.