Fabrication and Characterization of Taurine Functionalized Graphene Oxide with 5-Fluorouracil as Anticancer Drug Delivery Systems.

Recently, nanocarrier systems for cancer drugs, especially GO-based drug delivery systems, have become a boon for cancer patients. In this study, we choose Tau to functionalize the GO surface to improve its biocompatibility. Firstly, nano-scale GO was synthesized by the modified Hummer's method and ultrasonic stripping method. The taurine-modified graphene oxide carrier (Tau-GO) was synthesized by chemical method to obtain Tau-GO that has a good dispersibility and stability in water, with a zeta potential of - 38.8 mV and a particle size of 242 nm. Based on the encapsulation efficiency evaluation criteria, the optimal formulation was determined to combine Tau-GO and 5-FU by non-covalent bonding. The 5-FU-Tau-GO was more stable in neutral environment than in acidic environment, and with a certain PH response and sustained release effect. In vivo, we compared oral and intravenous administrations of 5-FU and 5-FU-Tau-GO, respectively, using pharmacokinetic tests and related parameters and showed that 5-FU-Tau-GO oral or intravenous administration prolongs the action time of 5-FU in the body and improves its bioavailability. In addition, the inhibition of HepG2 cells that was measured by the MTT assay, showed that the IC value of 5-FU was 196 ± 8.73 μg/mL, and the IC value of 5-FU-Tau-GO was 65.2 ± 0.7 μg/mL, indicating that 5- FU-Tau-GO is more potent against HepG2 cells and has a stronger inhibitory effect on cancer cells. The effect on cell morphology that was measured using the AO/EB staining also showed that 5-FU-Tau-GO not only disrupted cells, but also significantly induced apoptosis compared to 5-FU. We also verified by computer aided design that Tau-GO can bind better to 5-FU than to the unmodified GO, and that the formed 5-FU-Tau-GO system is more stable, and conducive to the transfer and release of 5-FU in vivo.