Supramolecular poly(N-acryloylmorpholine)-b-poly(d,l-lactide) pseudo-block copolymer via host-guest interaction for drug delivery

Abstract

In the present study, a pseudo-block copolymer was prepared from β-cyclodextrin terminated poly(N-acryloylmorpholine) (β-CD-PNAM) and adamantine-terminated linear poly(D,L-lactide) (AD-PDLLA), through host-guest interaction between β-CD and AD groups. Initially, the hydrophilic polymer PNAM was synthesized using reversible addition fragmentation polymerization, which was further linked to N3-β-CD through click reaction. In parallel, an AD terminated hydrophobic polymer, AD-PDLLA was synthesized using ring opening polymerization. The synthesized polymers were characterized by means of 1H NMR, gel permeation chromatography and fourier transform infrared. Subsequently, the formation of a pseudo-block copolymer via inclusion complexation between the β-CD core and AD-moiety was confirmed by 2D-NOESY NMR and self-aggregation of the pseudo-block copolymer was investigated by fluorescence spectroscopy. In addition, doxorubicin (DOX) a hydrophobic drug was loaded into the supramolecular micelles and the release kinetics of DOX from the micelles was studied. The result revealed that DOX release was accelerated as the pH reduced from 7.4 to 6.4.