Synthesis and Characterization of Functionalized Graphene Based Nanocomposites for Biomedical Applications

Abstract

Present research focused on the synthesis of stable, water dispersible surface modified multifunctionalized graphene nanocomposites to enhance therapeutic efficacy, anticancer theranostics with reduced toxicity and to get controlled targeted drug action for biomedical applications. The functionalization of graphene oxide can be achieved by PEGylation of green synthesized metal oxide nanoparticles (like CONPs/AgNPs/IONPs) decorated graphene nanocomposites with EDC-NHS activation chemistry. The successful development of RGO-CONPs/AgNPs/IONPs-PEG nanocomposites was investigated in detail by different analytical techniques. Hydrodynamic diameters in nano range and polydispersibility index values closer to 0.05 indicate the nanocomposites expected to have better colloidal stability and aqueous dispersibility. In order to overcome the side effects of doxorubicin (DOX), an anticancer drug, it was incorporated into amino PEGylated RGO-CONPs/AgNPs/IONPs nanocomposites. The higher percentage drug loading and more pH-responsive release of DOX from nanocomposites lead to promising nanocarrier for the anticancer drug. The nanocomposites were found to be able to efficiently transport DOX into acidic microenvironment of the targeted cancerous cells and then brought about cell death. Finally, cytotoxicity activities of the DOX loaded metal decorated nanocomposites were checked to know whether the original cytotoxic property of the pure drug was retained in such nanoformulations. It was found that DOX loaded RGO-IONPs-PEG nanocomposites were superior to others as far as their cytotoxic activities were concerned. Moreover, even AgNPs and CONPs containing nanoformulations were not inferior to the pure drugs due to cytotoxic activity of AgNPs and antioxidant property of CONPs. These results indicate that each DOX loaded nanoformulation was atleast not less cytotoxic than the respective drug. Thus, all the above mentioned information clearly suggests that each of the nanoformulations may be considered as stable, monodispersive and controlled release nanoformulation having satisfactory cytotoxicity. They even retained anticancer activity of the respective drugs. In addition, the RGO-IONPs-PEG nanocomposites were found to have superparamagnetic property which is an essential factor for cancer specific drug delivery with the ability of carrying anti-cancer drugs to targeted sites under an external magnetic field. It may be concluded that targeted drug carriers of PEGylated metal activated functionalized nanographene oxide could avoid the side effects of free DOX in tumor therapy. In this manner, the aims of the present study were fulfilled, i.e., stable, water dispersible surface modified functionalized metal/metal oxide decorated graphene nanocomposites, to enhance therapeutic efficacy and anticancer activity, were developed successfully for biomedical applications.