The Efficacy of Electrospun PAN/Kefiran Nanofiber and Kefir in Mammalian Cell Culture: Promotion of PC12 Cell Growth, Anti-MCF7 Breast Cancer Cells Activities, and Cytokine Production of PBMC

BACKGROUND: Kefiran is a useful polysaccharide made of branched glucogalactose which is produced by microorganisms. Here the anti-MCF-7 breast cancer cells activity of kefiran and cytokine productions (IL-6) of peripheral blood mononuclear cells (PBMC) treated by kefiran was studied. Also, the effect of using kefiran as a useful and cost-effective scaffold in neural stem cell culture (PC12 cell culture) was investigated. MATERIAL AND METHODS: Kefiran was produced from raw milk with 0.5% fat and 10 g of kefir grains. After incubation for 48 hrs at room temperature, the solvent collected (crude kefiran). These samples were kept at 100°C for 1 hr (boiled kefiran) and the supernatant was precipitated by ethanol (pure kefiran). Then, the electrospun nanofibers, pure polyacrylonitrile (PAN), PAN/kefiran 5%, and PAN/kefiran 10% were fabricated and used as scaffolds in the cell culture. The structure of fabricated was studied by SEM and the cytokine production (IL-6) in vitro in the cell culture supernatant of PBMC line after treatment with kefiran (1mg/mL, 5 mg/mL) and kefiran-PAN 5% and 10% were carried out by enzyme-linked immunosorbent assay (ELISA). The attachment of PC12 cells was examined by inverted microscope. Also, cytotoxicity of kefiran for PC12 and MCF7 cells and morphological changes of PC12 cells were evaluated by MTT and Cresyl violet staining (Nissl staining) respectively. RESULTS: The mean diameter of fabricated PAN/kefiran 5% and 10% nanofibers were 310.2±43.97 nm. The contact angle measurement results (26.9± 1.9 for the pure PAN scaffold vs 12.3± 1.13 for the PAN/kefiran) revealed enhanced hydrophilicity of scaffolds upon the incorporation of kefiran and PAN. Seeding of PC12 cells on the scaffolds showed that fabrication of kefiran into PAN led to the enhancement of cell attachment, proliferation, and morphological changes. Also, the promotion of PBMC growth and decreasing of MCF7 cell lines viability were shown through MTT assay. No significant changes were measured for the level of IL-6 in PAN/kefiran 5% treated cells compared to the control (p ≥ 0.05). CONCLUSION: These results suggest superior properties of kefiran/PAN nanofibrous scaffolds for the neural stem cell culture especially for repairing injured spinal cord. Also, the pure kefiran could be used for the enhancement of PBMC growth and reducing the MCF7 cancerous cells growth. So, using biocompatible, anti-bacterial, and anti-tumor kefiran/PAN nanofibers for regenerative medicine seems promising.