Random cationic copolymers as nanocarriers for ovalbumin

Abstract

In this study, the utilization of poly[quaternized (2-(dimethylamino)ethyl methacrylate-co-(oligo ethylene glycol)methacrylate)] cationic nanoaggregates and their double-hydrophilic precursors as nanocarriers for ovalbumin delivery purposes is presented. The synthesis of the P(DMAEMA-co-OEGMA) random copolymers through RAFT polymerization was followed by the hydrophilic/hydrophobic chemical modification with methyl iodide (CH3I), 1-iodohexane (C6H13I) and 1-iododecane (C12H25I) of DMAEMA segments. The resulting four copolymers were investigated regarding their self-assembly behavior in aqueous media, further demonstrating the formation of nanoscale aggregates in aqueous media. Owning to the positive surface charges these aggregates were consequently complexed through strong electrostatic interactions with ovalbumin molecules at different OVA(−)/pol(+) charge ratios. Light scattering techniques evidenced the efficacious formation of complexes, whose mass, size, and surface charge are strongly dependent on the mixing ratio, whilst fluorescence spectroscopy, UV–Vis, and ATR-FTIR spectroscopy studies substantiated that no conformational changes of ovalbumin molecules occurred during the complexation process. Moreover, OVA/polymer complexes manifested good colloidal stability in simulated biological environments with the addition of NaCl salt up to salt levels of human blood, and with the FBS interactions studies.