Cytotoxicity of Graphene Oxide (GO) and Graphene Oxide Conjugated Losartan Potassium (GO-LP) on Neuroblastoma (NB41A3) Cells.

Despite several advancements in the biomedical sciences, an efficient cancer therapy still remains a challenge. Nanomedicines have shown potential to overcome certain roadblocks faced in the existing treatment modalities. Losartan potassium (LP) which is a known vasodilator also exhibits anti fibrolytic and anti-metastatic properties altogether. Further, also being a potential angiotensin II type 1 receptor antagonist, it has been well explored for down regulating tumourogenic biomarkers like VEGF-A (Vascular endothelial growth factor A) and suppression of neovascularization, making it a suitable drug to target for cancer treatment. Besides this, it too reflected the stimulation of pro apoptotic signaling pathways. But due to its lower bioavailability and extensive hepatic metabolism its therapeutic index reduces down. Thus, the present study is focused on designing a nano-delivery system using graphene oxide (GO) as a nano-vehicle and conjugated the LP with it. Then, the successful synthesis of GO and GO-LP nano conjugates were characterized by high-resolution transmission electron microscopy, X-ray diffraction, FTIR and UV visible spectroscopy, confirming the formation of nanosheets. The qualitative morphological evaluation of NB41A3 neuroblastoma cell line treated with bare GO, LP and GO-LP using microscopy and DAPI staining revealed the inhibitory action of GO-LP nano conjugate on cell proliferation. Additionally, the cytotoxicity was also estimated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), Nitric oxide (NO) and Lactate dehydrogenase (LDH) assays. The results show that GO-LP significantly suppresses the cell viability in comparison to control and bare GO suggesting that the designed system may express its potential to be used with existing chemo drugs for the treatment of neural cancers.