Effect of bisphosphonate/graphene oxide complex on proliferation and differentiation of mesenchymal stem cells and breast cancer cells

Bisphosphonates have strong healing impact on postmenopausal osteoporosis and also apoptotic effect on breast cancer cells (MCF-7). Zoledronic Acid (ZOL) is a third generation (nitrogen contained) bisphosphonate. In this study, the effects of ZOL, Graphene Oxide (GO), and conjugation of these two samples (ZOL-GO) were observed on both cell lines of human bone marrow mesenchymal stem cells (MSC) and of breast cancer cells (MCF-7). The conjugation of ZOL (Sigma, 10 mg powder) and GO (Sigma, 2mg/mL) was obtained via mixing them with magnetic stirrer and sonicator. During the preparation of samples; ZOL stock solution was obtained by mixing ultra pure water (5mg) with ZOL powder (10 mg) and GO stock solution was obtained by mixing ultra pure water (4500 µL) with GO (500 µL). The final concentrations that used in this study were for ZOL were 200 µM, 50 µM, 12.5 µM and for GO were 11.7 ng/mL, 2.91 ng/mL, 0.73 ng/mL and for ZOL-GO complexes were 200 µM ZOL - 11.7 ng/mL GO, 50 µM ZOL - 2.91 ng/mL GO, 12.5 µM ZOL - 0.73 ng/mL GO. Fourier Transform Infrared Spectroscopy (FTIR) results was obtained for the characterization of the samples. For cell proliferation, Alamar Blue viability test and Acridine Orange (AO) dying was conducted. The viability of MSC was not affected significantly in the presence of ZOL-GO complex however the viability of MCF-7 cells remarkably decreased on day 3. For observing cell differentiation, Scanning Electron Microscopy (SEM) and Alizarin Red S staining results was used. The mineralization of the MSC was reinforced by the presence of ZOL- GO complex.