Polymer–Aptamer Hybrid Emulsion Templating Yields Bioresponsive Nanocapsules



This article describes the synthesis of a DNA–polymer, being the nucleotide sequence an aptamer selected in vitro to target specifically the immunoglobulin E (IgE) protein, an allergy biomarker. Subsequent to coupling to poly(2-alkyl-2-oxazoline) with N-Boc protected amino acid side chains, the resulting amphiphilic DNA–polymer hybrid composed of the water-soluble DNA fragment grafted to the hydrophobic polymer segment can be regarded as a high molecular weight analogue of a surfactant. It is demonstrated that the copolymer–aptamer stabilizes efficiently submicrometer size oil-in-water and water-in-oil emulsions, by dynamic light scattering, microscopy, and reflectometry. Particularly interesting is that the aptamer remains functional after coupling to a polymer backbone, stabilization of the emulsion droplets, and locking of the structure subsequent to cross-linking polymerization. The resulting nanocapsules still target specifically the IgE protein. The biological-stimulus responsiveness of the structures is of high potential for future developments of carriers for sustained and targeted delivery.