Noncovalent Functionalized Graphene Nanocarriers from Graphite for Treating Thyroid Cancer Cells

Here, biocompatible graphene (G) nanocarriers decorated with iron oxide nanoparticles (IONPs) were prepared using 2-(methacryloyloxy)ethyl phosphorylcholine (MPC) and poly(ethylene glycol) monomethacrylate (PEGMA). For this, we report the use of graphite directly instead of graphene oxide or reduced graphene oxide. Graphene nanocarrier (in situ GIOPMPC) was prepared in one-pot by in situ copolymerization of MPC and PEGMA monomers in the presence of IONPs and G. GIOPMCP nanocarriers were prepared by sonication using PMPC-co-PEGMA copolymers in the presence of IONPs and G. The prepared graphene nanocarriers were thoroughly characterized by various techniques. The analyses confirmed the successful preparation of nanocarriers with even distributions of PMPC-co-PEGMA and IONPs on surface G. The IONPs were coordinated through the phosphate groups in PMPC. Excellent dispersibility of the graphene nanocarriers in water enabled drug delivery applications. The prepared nanocarriers did not show significant cytotoxicity to the thyroid cancer cells up to 8 mg/mL (IC₅₀: 38.26 mg/mL). Thyroid cancer cells were stably transduced with a bioluminescent reporter to monitor cell cytotoxicity. Doxorubicin (DOX) was loaded onto in situ GIOPMPC nanocarriers at two different concentrations and was successfully delivered to thyroid cancer cells, resulting in strong cytotoxicity. Moreover, signaling mechanistic analyses showed apoptosis activation, inhibition of anti-apoptosis and proliferation, and increased DNA damage in the thyroid cancer cells.