Development of Magnetite-Graphene Oxide Nanoplatforms for pH-Sensitive Doxorubicin Delivery and Cytotoxicity Evaluation

Objective: This study aimed to develop and characterize a magnetite-graphene oxide (m-GO) nanoplatform for the controlled, pH-sensitive delivery of doxorubicin (DOX), with an emphasis on improving targeted anticancer activity and minimizing systemic toxicity. The potential application of this system in both human and veterinary oncology was also considered. Materials and Methods: Magnetite-functionalized graphene oxide (m-GO) nanoparticles were synthesized by decorating graphene oxide with Fe₃O₄ nanoparticles. DOX was loaded onto the m-GO system, and the loading was confirmed by UV-Vis and FTIR spectroscopy. The nanoparticles were characterized for particle size and zeta potential. In vitro drug release studies were conducted at pH 5.5 and 7.4 to assess pH sensitivity. Cytotoxic effects were evaluated using the MTT assay on MCF-7 human breast cancer cells. Drug release kinetics were also analyzed to determine the release mechanism. Results: The synthesized nanoparticles had a mean particle size of 42.18 ± 4.22 nm and a zeta potential of −19.3 ± 1.54 mV. Drug release studies showed enhanced DOX release at acidic pH (5.5), indicating pH sensitivity. The MTT assay demonstrated dose-dependent cytotoxicity, with free DOX showing immediate higher toxicity, while DOX-loaded m-GO provided controlled cytotoxic effects. Release kinetics analysis revealed a Fickian diffusion-controlled mechanism. Conclusion: DOX-loaded m-GO nanoparticles exhibited favorable physicochemical properties and pH-sensitive drug release behavior. Their ability to provide controlled drug delivery with sustained cytotoxicity suggests that they may serve as promising nanocarrier systems for targeted cancer therapy, with potential applications in both human and veterinary medicine.