Development of cancer-targeted nano gold functionalized ruthenium(III)-doxorubicin complex: Synthesis, characterization and evaluation of DNA cleavage, anticancer and bioimaging activity

Metal-based drugs have attracted greater attention for cancer diseases because of biological relevance. However, some drawbacks are present in the metal complexes such as low stability and low bioavailability. Nanomaterials functionalized metal complexes can protect the stability and enhanced the bioavailability. In the present study, Nano gold functionalized ruthenium(III) complex from doxorubicin have been synthesized from ruthenium(III) complex and characterized using various spectrochemical techniques such as IR, UV, and NMR. In the metal complex, Doxorubicin (DOX) acts as a monobasic bidentate ligand and is coordinated through the carbonyl oxygen and phenolate oxygen of the anthracene ring. Based on spectral evidences, the complex [Ru(DOX)(PPh3)2Cl2] has an octahedral geometry. The Nano Au-Ru(III) DOX is analysed for their size, and morphology using XRD, SEM and HRTEM. X-ray diffraction pattern revealed that the complex has nanocrystalline in nature. The Nano Au-Ru(III) DOX is spherical shape and particle size is less than 15 nm. The DNA cleavage activity of [Ru(DOX)(PPh3)2Cl2] and Nano Au-Ru(III) DOX has been evaluated using pUC18 plasmid DNA and the results showed significant cleavage. The [Ru(DOX)(PPh3)2Cl2] and Nano Au-Ru(III) DOX have been tested against human breast cancer (MCF-7) and leukemia cancer cell lines (K-562) in vitro for its antitumor effects. The tumour activity of the Nano Au-Ru(III) DOX showed more promising activity than the [Ru(DOX)(PPh3)2Cl2]. The cell imaging of the Nano Au-Ru(III) DOX was examined against epithelial human breast cancer cell line (MDA-MB-231) using fluorescent microscopy. The fluorescence images showed high scattering light in tumour tissue at 100 µg/mL Hence, Nano Au-Ru(III) DOX can serve as a promising drug for cancer therapy and cellular imaging.