Crosslinkable/functionalizable poly(2-oxazoline)­based micelles. (December 2019)

• Record Type: Journal Article
• Authors: Rossegger, Elisabeth; Pirolt, Franz; Hoeppener, Stephanie; Schubert, Ulrich S.; Glatter, Otto; Wiesbrock, Frank
• Is Part Of: European polymer journal. Volume 121(2019)
• Publication Date: 2019-12
• Subjects: Block copoly(2-oxazoline)s -- Critical micellar concentration -- Thiol-ene click reaction -- Crosslinked micelles -- Dynamic light scattering -- Worm-shaped micelles; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2019.109305
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Highlights: Amphiphilic diblock copoly(2-oxazoline)s composed of EtOx and Dec = Ox form micelles. The shape of these micelles is not spherical, but anisotropic. Such micelles can be crosslinked by thiol-ene click recations. The micelles can take up oil upon an increase of their hydrodynamic radius. Abstract: Considering the pseudo-livingness of the cationic ring-opening polymerization of various 2-oxazoline monomers, micelles formed by amphiphilic diblock copoly(2-oxazoline)s are potential candidates for drug delivery. Copoly(2-oxazoline)s of the composition poly(2-ethyl-2-oxazoline)100-n - block -poly(2-dec-9′-enyl-2-oxazoline)n (n = 5, 10, 15) were found to form micelles in aqueous solution. The hydrophobic cores of these non-spherical micelles could be crosslinked by the thiol-ene reaction with glycol dimercapto acetate, the ester bonds of which can be cleaved by esterases. While the hydrodynamic radii of the non-crosslinked micelles increased if the hydrophobic block of poly(2-dec-9′-enyl-2-oxazoline) grew larger, the opposite trend could be observed for the crosslinked micelles. In the course of an oil uptake study, the hydrodynamic radii of the crosslinked as well as non-crosslinked micelles increased. In oil-filled micelles of poly(2-ethyl-2-oxazoline)100-n - block -poly(2-dec-9′-enyl-2-oxazoline)n (n = 5, 10, 15), the hydrodynamic radii of the non-crosslinked micelles were significantly larger in comparison with the crosslinked ones in case of n = 5 and 10, while the hydrodynamic radii of non-crosslinked and crosslinked micelles were of the same range in case of n = 15. The changes of diameter in micelles with polar molecules such as Zidovudine covalently attached to the hydrophobic core support the proposed antagonism of the inclusion of non-polar/polar molecules into the micelles' cores and the degree of crosslinking.