Facile synthesis of drug-conjugated PHPMA core-crosslinked star polymers

Abstract

Poly(N-(2-hydroxypropyl)methacrylamide) (PHPMA), a biocompatible and non-immunogenic polymer, was used to form core-crosslinked star polymers for potential drug delivery applications. The conditions for the formation of the PHPMA stars were studied by varying the molecular weight of the PHPMA unimers, [crosslinker] : [unimer] ratios, and solvent. The optimized conditions were then used to form drug-loaded PHPMA star polymers by directly copolymerizing an HPMA-modified anticancer drug, methotrexate, during the crosslinking reaction of PHPMA unimers. The incorporation of the drug was confirmed by ¹H NMR spectroscopy, and UV-visible spectroscopy was used to determine a drug loading of 20 wt%. Our initial drug release studies showed that the addition of an esterase induced drug release.