AIPs were recently synthesized from either poly(ethylene glycol) (PEG) and aliphatic dicarboxylic acids or PEG and polytetrahydrofuran (PTHF). Macromolecules of amphiphilic polymers consisting of hydrophilic and hydrophobic constituents were shown to form micelles and to self-assemble in micellar nanostructures, changing conformation in response to changes in the polymer composition, concentration, and solvent polarity. Controlled self-assembly is targeted in our approach by having a precise number of short hydrophilic and hydrophobic fragments with a well-defined length in the amphiphilic macromolecules. 1H NMR technique has been used for the systematic study of AIP micelles and micellar assembles, as well as for the study of interactions between polymers and peptides. It has been shown that in an aqueous medium the macromolecules of AIPs form micellar structures with an interior consisting of the polar PEG fragments and an exterior made up of the lipophilic -(CH2)n- moieties. Adding the peptide leads to a broadening of the signals attributed to the PEG protons indicating that the motions of the PEG fragments became limited, obviously, due to their interaction with peptide molecules. Also, a peak of protons of dodecanedioic acid moieties narrows slightly and moves upfield. It is concluded that hydrophobic fragments of the peptide are included into the hydrophobic interior of the micellar structures. Microphase separation and further micellization of the AIP macromolecules in an aqueous solution lead to interactions between AIP and the peptide resulting in the formation of mixed micelles. The inner part of these micelles consists of the hydrophobic moieties of both AIP and the peptide whereas the hydrophilic fragments of AIP and the peptide build up a micellar exterior. Hence, the “host–guest” interactions between peptides and self-assembled micellar nanostructures from AIPs by changing the polymer concentration and polymer/peptide ratio result in formation of stable AIP–peptide mixed micellar structures in aqueous solution. They can be considered as a potential material for localized delivery of peptides and release through a stimuli-responsive mechanism.

1H NMR study on polymer-peptide mixed micelles for adjuvant application

253rd National Meeting (2017)

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