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A series of products based on tert-butylcalixarene have been synthesized by anionic polymerization of ethylene oxide. The resulting products are amphiphilic octopus-shaped macromolecules, consisting of a hydrophobic calixarene core and four arms of hydrophilic poly(ethylene oxide) chains. In aqueous solutions the polyoxyethylated tert-butylcalixarenes were found to self-associate above certain CMC determined by dye solubilization technique. The light scattering study reveals that the polyoxyethylated tert-butylcalixarenes form aggregates of narrow size distribution and hydrodynamic diameters ranging from about 155 to 245 nm and aggregation numbers from tens to hundreds macromolecules per particle depending on the degree of polymerization of the PEO chains. An in vitro biocompatibility study showed that the tested compounds are practically devoid of intrinsic cytotoxic and hemolytic effects and moreover they failed to modulate the mitogen-induced interleukin-2 release from the human T-lymphocyte cell line Jurkat E6-1. Taken together the excellent in vitro biocompatibility profile and the favorable physicochemical characteristics of the tested polyoxyethylated calixarenes give us reason to consider them as promising for further evaluation as drug delivery platforms.