Supramolecular polymer-based transformable material for reversible PEGylation of protein drugs.

We herein developed a transformable mixing-type material for reversible PEGylation of protein drugs using a supramolecular backbone polymer, that is, polyrotaxane possessing both amino groups and PEG chains (PEG-NH-PRX). We expected that PEG-NH-PRX provides amino groups to interact with protein drugs on demand because the mobility of amino groups in PEG-NH-PRX was high. In fact, PEG-NH-PRX formed complexes with protein drugs efficiently compared to PEGylated amino-dextran (PEG-NH-DEX), a control material fabricated with a macromolecular backbone polymer. Moreover, PEG-NH-PRX markedly improved the stability of antibodies and prolonged the hypoglycemic effects of insulin without loss of bioactivity, compared to PEG-NH-DEX. These findings suggest that the supramolecular material, PEG-NH-PRX, is a promising reversible PEGylation material for protein drugs compared to macromolecular materials.