• Delivery of flavonoid salvigenin to mouse breast cancer cells by montmorilonite/chitosan nanocomposites
  • Farnoosh Attari,1,* Maryam Banaeei,2 Sepideh Khoee,3 Mahdi Moridi Farimani,4
    1. Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran, Iran
    2. Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran, Iran
    3. Polymer Chemistry Department, School of Science, University of Tehran, Tehran, Iran
    4. Department of Phytochemistry & Chemical Engineering, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, Tehran, Iran


  • Introduction: Breast cancer is one of the most common causes of death related to cancer in women and many reports proved that herbal substrates such as flavonoids are able to induce apoptosis in this type of cancer. However, flavonoids lack proper solubility and bioavailability which limit their application in the medicine. Nanotechnology is one of the best strategies to overcome limitations related to drug delivery. Nanoclays such as montmorilonite (MMT) are nanolayered silicates with a proper biocompatibility, suitable mechanical properties, and high specific surface area which possess great potentials to be used in the medicine. In our study, we have used MMT/chitosan nanocomposite (MMT-C) as a delivery system to be loaded with the flavonoid salvigenin in order to investigate its apoptotic effects on 4T1 breast cancer cells.
  • Methods: The nanocomposites were fabricated by adding salvigenin to the solution of MMT and chitosan and the obtained nanocomposites were designated as MMT-C-S. The fabricated nanocomposites were characterized using scanning electron microscopy (SEM), dynamic light scattering (DLS), infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Moreover, we have determined drug loading via spectrophotometry. To analyze the effect of nanocomposites on the cell proliferation and viability of cancer cells, MTT assay was performed. Also, to determine the apoptotic effect of MMT-C-S on 4T1 cells, Annexin/PI staining and cell cycle analyses were used.
  • Results: SEM images demonstrated the nanosheet morphology of MMT-C in the range of 470 nm with the surface charge of -8.1 mV. TGA results confirmed the thermal stability of MMT-C and the presence of chitosan between the layers of MMT nanosheets. Drug loading and drug encapsulation were calculated to be 17% and 65%, respectively. Drug release was 30% within 24h followed by a slow release within the next 200h. The MTT data indicated the reduced proliferation of cancer cells via treatment with MMT-C-S compared to free salvigenin. Also, loaded nanocomposites increased the apoptotic population of the 4T1 cells up to 50%. Moreover, the cell cycle analysis proved that the population of Sub-G1 cells was augmented in the cells treated with MMT-C-S which was indicative of apoptosis induction
  • Conclusion: Our data showed the fact that MMT nanosheets promoted the delivery of salvigenin to breast cancer cells and effectively induced apoptosis in these cells which makes them a potential candidate to treat triple-negative breast cancers.
  • Keywords: salvigenin, breast cancer, nanoclay