Investigation of use in 5-FU release: Synthesis of temperature and pH responsive P(NVCL-co-VIm)/PVP hydrogels

5-fluorouracil (5-FU) forms the basis of many chemotherapy regimens and is one of the most common preferred chemotherapeutic drugs. In this study, the synthesis of temperature and pH responsive hydrogels in the release of 5-fluorouracil (5-FU) was studied to prevent drug release during blood circulation and uncontrolled overdose drug concentration at the tumor site. In this regard, the synthesis of temperature sensitive polymer Poly(N-vinylcaprolactam) PNVCL, temperature and pH sensitive polymers P(NVCL-co-VIm) and P(NVCL-co-VIm)/PVP hydrogels was carried out by the free radical polymerization method. DSC analysis revealed that as a result of copolymerization of PNVCL with hydrophilic 1-vinylimidazole (VIm) and polyvinylpyrrolidone (PVP), the lower critical solution temperature (LCST) increased and was close to the human body temperature. In addition, it was concluded from pH sensitivity analysis that the swelling ratios of the hydrogels changed with the medium pH. Additionally, hydrogels swelled in the acidic medium but shrunk in the alkaline medium. Accordingly, 5-FU release was investigated in different temperatures (25 °C and 37 °C) and pH (pH 5.5 and 7.4) medium and approximately 96% drug release was reached at 37 °C and pH 7.4. Consequently, P(NVCL-co-VIm)/PVP hydrogels at different pH and temperature mediums could be beneficially utilized as a material with the potential to be used in targeted drug delivery systems.