Fabrication and Characterization of L-Glutamine-Functionalized Magnetic Graphene Oxide as a Novel Bio-Platform for Controlled Release of 5-Fluorouracil

Surface modification with biomolecules can overcome Graphene Oxide (GO) restrictions in biocompatibility, cellular internalization, and drug delivery effectiveness, hence  suitable for a wide range of biomedical applications. In this study, a biocomposite (L-glutamine-functionalized magnetic graphene oxide (L-Gln/MGO)) was prepared and used as a suitable nanoscale carrier with high drug loading capacity and excellent release properties for 5-fuorouracil (5FU), an anticancer drug. The optimum pH for maximum drug adsorption was determined as 4 at 293 K and as the temperature increased, the adsorption capacity decreased due to the exothermic nature of the adsorption process. Some well-known models, including pseudo-first-order, pseudo-second-order, and Intraparticular Diffusion (IPD), were applied to examine the kinetics of adsorption. Additionally, the Langmuir, Freundlich, and Redlich-Peterson models were used to investigate the adsorption isotherms. The obtained results showed that the adsorption process adhered to the Langmuir isotherm and pseudo-second-order kinetic models. Nearly 26% of 5FU was released in the simulated stomach fluid at the pH of 1.2 and temperature of 37 °C in the first 30 minutes while 32% of which was released in the simulated intestinal fluid at the pH of 7.4 during the next 30 hours. The obtained results might be helpful for designing a controllable loading and targeted 5FU drug delivery system.