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

Abstract

5-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.