Hydrolyzed Poly(2‐plenyl‐2‐oxazoline)s in Aqueous Media and Biological Fluids

Abstract

AbstractHydrolyzed poly(2‐phenyl‐2‐oxazoline)s (PPhOx) are synthesized by partial hydrolysis of PPhOx in order to produce self‐assembling copolymers with chargeable and hydrophobic units. The resulting poly(ethylene imine‐co‐2‐phenyl‐2‐oxazoline) [P(EI‐co‐PhOx)] amphiphilic copolymers contain phenyl‐oxazoline and ethylene imine segments in a random sequence and their chemical structure is confirmed by 1H NMR and attenuated total reflection‐Fourier transform infrared spectroscopy. Static and dynamic light scattering experiments show that in aqueous solutions the random copolymers associate into aggregates of sizes in the range between 50 and 200 nm depending on the solution conditions and hydrophobic content. The positive charge of the nanoaggregates that is caused by protonation of the amine nitrogen is confirmed by zeta potential measurements. Self‐assembly in phosphate buffered saline results in large aggregates. The aggregates are proved to interact with fetal bovine serum proteins. This investigation shows that hydrolyzed phenyl oxazoline‐based copolymers provide stable amphiphilic nanoparticles able to interact with biological macromolecules for biotechnological and pharmaceutical applications.