Recently, graphene oxide (GO) has attracted considerable interest to researchers in materials and biomedical science because of its some unique physical and biological properties, such as excellent water dispersibility, biocompatibility, structural stability, high drug loading efficiency and controlled drug release behavior, which are favorable for its potential use for medical imaging and drug delivery. The functionalization of OH-terminated fourth generation poly (amido amine) (PAMAM) dendrimer (DEN-OH) and folic acid (FA) on GO and the loading of anticancer drug doxorubicin (DOX) on functionalized GO are reported in this work. Physical and chemical properties of functionalized GO and also its cytotoxic effects are also described.
This multifunctional nanocomposite named GO/Den-OH/FA/DOX was obtained as the following procedures: DEN-OH was applied to modify GO surface by connection through the esterification reaction. In order to improve its tumor targeting imaging and treatment efficiency, the obtained intermediate product was further modified with FA. Finally, the nanocomposite was allowed to load anticancer drug, DOX.
Nanoscaled GO with particle size around 110 nm was also synthesized by ultrasonication for 4 h and followed by filtration. The obtained NGO was further functionalized with DEN-OH, and then FA as the targeting ligand was connected to the GO surface through chemical reaction between carboxyl group of FA and amino group of DEN-OH. The properties of GO with different particle size are compared in this work.
The ability for the efficient delivery and the enhanced special cellular uptake into cancer cells is one of major focuses on this research. Cell uptake studies were carried out using DOX-loaded multi-functionalized GO to evaluate their targeted delivery property and toxicity to tumor cells. The results show that this multi-functionalized GO has potential applications for targeted delivery and the controlled release of anticancer drugs.

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