RESUMO
Background: Today, increasing attention is being paid to the application of biocompatible polymers as drug carriers with low cytotoxicity in drug delivery systems to enhance the therapeutic effects of anticancer agents. Materials and Methods: In this study, a biocompatible synthetic polymer (grafted on graphene oxide), composed of N-isopropylacrylamide and 1-vinyl-2-pyrrolidone with L-lysine segments (Lys/PNIPAM-PVP/GO), was developed as a nano-vehicle for the drug. This platform was used for the delivery of fluorouracil (FU) to A549 human lung cancer cells. The superior characteristics of the platform included low-cost precursors, easy synthesis, and the presence of many functional groups for loading drugs. To determine and compare the cytotoxic effects of free FU and its formulated form on the A549 cells, MTT assay was performed; the results showed no significant toxicity difference between the two treated groups (free and formulated FU). For further evaluations, cellular uptake assays were performed via fluorescence microscopy and flow cytometry. Results: Both analyses revealed the low internalization of nano-vehicle into the A549 cells, with 4.31% and 8.75% cellular uptakes in the first two and four hours of treatment. Therefore, the low penetration rate reduced the toxicity of drug-loaded nano-vehicle. Conclusion: Finally, DAPI staining and Annexin V-FITC staining were performed as complementary techniques to determine cell apoptosis.
RESUMO
Despite the advances in the development of chemotherapeutic agents, resistance to chemotherapy and adverse side effects are still big challenges against successful cancer treatment. To overcome these problems, one strategy is the application of nanomaterials and drug delivery systems to efficiently deliver the anticancer agents to tumour tissues with minimum toxic effects on healthy organs. In this study a graphene oxide nanohybrid (GO/NHs) was designed and fabricated for the delivery of chemotherapeutic agent fluorouracil (FU) to the breast cancer MCF7 cells. After preparation and characterization of GO/NHs, several biological analysis including haemolysis assay, cytotoxicity assay, cellular uptake, apoptosis assay, and protein expression were performed. The cytotoxic effects of FU, FU loaded GO/NHs (FU-GO/NHs), and blank GO/NHs was determined by MTT assay. The results of MTT assay showed no significant cytotoxicity for blank nano-hybrid on MCF7 cells. Furthermore, FU-GO/NHs were more cytotoxic than free FU. The uptake analysis results showed that developed nanocarrier could completely be internalized into the cells in the first hour. Besides, apoptotic effects and nuclear morphology changes of cells was evaluated by DAPI staining under fluorescent microscopy. Protein expression levels of p53, PARP, cleaved PARP, Bcl-2, and Bax were determined by western blot analysis. Western blot results showed higher levels of p53 and cleaved PARP after treatment with FU-GO/NHs, however, no substantial effect was observed for Bax and Bcl-2 protein concentrations.
