Simple preparation of maltose-functionalized dendrimer/graphene quantum dots as a pH-sensitive biocompatible carrier for targeted delivery of doxorubicin.

In the present study, a novel magnetic carbon modified with 3-aminopropyltrimethoxysilane (APTMS) using maltose disaccharide molecule as a green capping agent, and a third-generation triazine dendrimer (Fe₃O₄@C@TD-G3) was then covalently attached to their surface. Eventually, Fe₃O₄@C@TD-G3 was reacted with graphene quantum dots (GQDs) for the preparation of final Fe₃O₄@C@TDGQDs microspheres. The obtained compound was successfully applied as a novel magnetic carrier for the Doxorubicin (DOX) drug delivery. Various techniques such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Zeta potential, Ultraviolet-visible (UV-vis), Atomic force microscopy (AFM), Scanning electron microscopy (SEM), Energy-dispersive X-ray (EDX), Brunauer-Emmett-Teller (BET), Vibration sample magnetometer (VSM), and Fluorescence and Photoluminescence (PL) analysis were used to approve the synthesis of microspheres. Drug release studies carried out at different pHs (pH 5, 6.8 and 7.4) and the cytotoxic assay was evaluated for DOX-loaded Fe₃O₄@C@TDGQDs against Human lung cancer cell lines (A549). The drug release assay showed that the amount of the DOX release from dendrimer was noticeably pH depended. In-vitro cytotoxicity test results indicated that DOX loaded Fe₃O₄@C@TDGQDs was non-toxic on the A549 cell. The obtained results demonstrated that Fe₃O₄@C@TDGQDs microspheres can be used as a new safe and efficient vehicle for the delivery of different cancer drugs.