Orthogonal Chemoselective Assembly of Hyaluronic Acid Networks and Nanogels for Drug Delivery

Functionalization of hyaluronic acid (HA) with orthogonally reactive aldehyde and thiol groups permitted simultaneous bioconjugation and networking/nanostructuring of the HA chains for potential use as local and systemic delivery vehicles for medical therapies. In one experiment, the thiol–disulfide exchange reaction and carbazone chemistry were employed to construct a disulfide hydrogel matrix of HA macromolecules with the carbazone-linked poly(vinyl alcohol) prodrug of doxorubicin (PVA–DOX). In another experiment, orthogonal chemoselective reactions were utilized to prepare nanogel particles through conjugation of the polymeric PVA–DOX prodrug to HA and simultaneous attachment of hydrophobic fluorescent groups to the HA chains. The effect of the prodrug nanostructuring and functionalization with HA on the in vitro drug release and uptake by cancer cells was preliminary verified.