• Synthesis of Niosomes Loaded with Temozolomide and Quercetin and Investigating its Effect on Cell Proliferation and SOD activity in Brain Tumor Cell line U251
  • Reyhaneh Baniali,1 Zahra Kianmehr,2,* Maryam Ghanbari,3
    1. Department of Biology, SR.C., Islamic Azad University, Tehran, Iran
    2. Department of Biochemistry, NT.C., Islamic Azad University, Tehran, Iran
    3. Department of Biochemistry, NT.C., Islamic Azad University, Tehran, Iran


  • Introduction: Glioblastoma is one of the most aggressive and lethal primary brain tumors, characterized by rapid proliferation and resistance to conventional therapies. Standard treatment often involves surgical resection followed by radiotherapy and chemotherapy, primarily using temozolomide. Despite initial responses, the efficacy of temozolomide is severely limited due to the emergence of resistance and its associated neurotoxicity. Consequently, there is an urgent need for novel therapeutic strategies that can enhance drug delivery and efficacy while reducing side effects. Niosomes, nonionic surfactant-based vesicles, have attracted attention as promising carriers for drug delivery systems, especially in the treatment of glioblastoma. Their ability to encapsulate lipophilic and hydrophilic agents, coupled with their capacity to facilitate sustained drug release, make them suitable for targeted therapy. In the present study, after synthesizing temozolomide (T) and quercetin (Q, a natural flavonoid with antioxidant and anticancer properties) loaded niosomes, the effects of their combined treatment on cell proliferation and superoxide dismutase (SOD) activity in the U251 brain tumor cell line were investigated.
  • Methods: Niosome capsules were synthesized by the thin-film hydration method. For this purpose, various properties including size and zeta potential of niosomes, percentage of drug encapsulation efficiency (QT) and cumulative release evaluation were measured and the optimal method and formulation for niosomes synthesis were selected. The absorption spectra of temozolomide and quercetin were measured in the wavelength range of 200 to 500 nm using a spectrophotometer. Then, the drugs were loaded into the capsule and the drug release rate was evaluated. Next, DLS test was performed to evaluate the size and zeta potential. After that, the cytotoxicity of the synthesized niosomes in U251 brain tumor cells was measured by MTT method at 24, 48 and 72 hours. Also, the level of SOD activity in treated U251 cells was measured after 48 hours.
  • Results: Using the thin-layer hydration method, niosomes showed an average size of 400 nm and an encapsulation efficiency of 84% for temozolomide and 96% for quercetin. Also, the maximum absorption in the wavelength range of 200 to 500 nm for temozolamide was 327 and for quercetin was 368 nm. The release of temozolamide and quercetin encapsulated in the capsule was investigated for 72 hours and the results showed that only 1% of the total drug was released within 48 hours. . The results of the DLS test showed that the synthesized niosomes had an appropriate size distribution and the zeta potential of these particles was calculated to be -3 mV. The dispersion index (PDI) of these particles was in the appropriate range. The results of the MTT test showed that at different concentrations and at different times (24, 48 and 72 hours), treatment of U251 cells with drug-containing niosomes (N-QT) caused a greater decrease in the percentage of viability than the drug alone (QT). Also, treatment with N-QT caused a significant increase in SOD activity compared to the QT and N groups.
  • Conclusion: These findings demonstrate the potential of niosomes as an effective delivery system for temozolomide and quercetin, which warrants further exploration of their mechanisms of action, particularly in terms of apoptosis induction and oxidative stress modulation.
  • Keywords: Glioblastoma, Niosomes, U251 cell line, Temozolomide, Quercetin