Design of polyrotaxanes as supramolecular conjugates for cells and tissues.

This research focuses on the supramolecular challenge of enhancing multivalent binding between ligands and proteins or biological receptors on cell surfaces. Our special interest is using supramolecular-structured polymers, namely, polyrotaxanes consisting of ligand-immobilized alpha-cyclodextrins (alpha-CDs) threaded onto a poly(ethylene glycol) (PEG) chain capped at both terminals with bulky end groups via biodegradable linkages. The structural characteristics of these polyrotaxanes involve sliding and rotational motion of the ligands immobilized on alpha-CDs along a PEG chain, thus facilitating access to binding sites on proteins. This approach provides a novel biomaterial design in the field of drug delivery and tissue engineering.