The novel calix[4]resorcinarene-PEG conjugate: Synthesis, self-association and encapsulation properties

The synthesis and study of self-association and encapsulation ability of new low toxic conjugate of tetraphenyleneoxypentylcalix[4]resorcinarene and methoxy-poly(ethylene glycole) (C5OPh-mPEG) were described. The conjugate is characterized by H-1, C-13 NMR, FT-IR, MS, SLS methods. In an aqueous solution the conjugate form multimicellar nanoparticles with low polydispersity value (0.1, DLS method). The self-association of the conjugate was studied by DLS, fluorescence, fluorescence anisotropy method, TEM, and SAXS methods. The SAXS data were detailed analyzed, and the conjugate associates structure as ellipsoidal core-shell particles was proposed. The encapsulation efficiency is a result of the affinity of the conjugate low rim substituents to substrates and reaches of 39.8, 26.7, and 28.9% toward naproxen, ibuprofen and doxorubicin drugs, respectively.