Controlled 5‐FU Release from P(NIPAM‐co‐VIm)‐g‐PEG Dual Responsive Hydrogels

Abstract

Abstract5‐fluorouracil (5‐FU) forms the basis of many chemotherapy regimens and is one of the most widely used chemotherapeutic drugs in the treatment of solid malignancies. In this study, (i) Poly N‐isopropyl acrylamide (PNIPAM) synthesized by free radical polymerization method, (ii) temperature and pH responsive P(NIPAM‐co‐VIm) synthesized by copolymerization of N‐isopropyl acrylamide (NIPAM) with 1‐vinyl imidazole (VIm) and (iii) the 5‐FU release of P(NIPAM‐co‐VIm)‐g‐PEG prepared by grafting with polyethylene glycol (PEG). In the temperature and pH sensitivity analyzes revelaed that the LCST value increased as a result of the treatment of PNIPAM with VIm and PEG, on the other hand the hydrogel in the swollen phase in the acidic environment, the hydrogel turned into a precipitated form as the environment became alkaline. To investigate the utilize of hydrogels, release mediums of two different pHs (pH 5.5 and 7.4) and two different temperatures (25 °C and 37 °C) were applied. The cumulative release results showed that the release ratio of 5‐FU was 95 % when the release medium pH was 7.4 and ambient temperature 37 °C. Consequently, P(NIPAM‐co‐VIm)‐g‐PEG hydrogels at different pH and temperature mediums could be beneficially utilized as an material with a potential to be used in targeted drug delivery systems.