Fabrication and characterization smart gold-polymer nanostructure as promising theranostic agent for dual-imaging and chemo-photothermal therapy of cancer: An in vitro study.

[Display omitted] • Smart Gold-polymer nanostructure was developed for dual CT/fluorescence imaging and chemo-photothermal therapy of cancer. • Pol-CD@GNSs-MTX showed significantly higher cell uptake compared to the Pol-CD@GNSs without MTX (P value < 0.001). • Combination chemo-PTT of MDA-MB231 cells with Pol-CD@GNSs-MTX led to the cells cycle arrest at the subG1 phase. • Combination chemo-PTT of MDA-MB231 cells with Pol-CD@GNSs-MTX led to apoptotic cell death. • NIR irradiation of cells pre-treated with synthesized nanoparticles showed efficient heat production rate. In order to enhance the effectiveness of cancer therapy, it is essential to have highly sensitive imaging techniques that provide accurate results and the selection of appropriate therapeutic strategies. Despite recent advances in technologies associated with tumor imaging, the application of conventional single-mode imaging is the subject of debate. Herein, we strategically engineered a nanostructure (GNSs-MTX@CD-Pol) designed from a pH-responsive polymer (Pol), gold nanostar (GNSs), carbon dot (CD), and methotrexate (MTX) as a theranostic agent for simultaneously fluorescent (FI) and X-ray computed tomography (CT) imaging and combination Chemo-Photothermal Therapy in response to near-infrared (NIR) laser irradiation. GNSs-MTX@CD-Pol NPs possess excellent photothermal conversion efficiency and dual FI/CT imaging properties, which are attributed to the strong NIR absorption and high atomic number of gold elements. Moreover, it is demonstrated that GNSs-MTX@CD-Pol NPs are effectively responding to tumor acidity. With the PTT, the growth of cancer cells can be remarkably ablated in vitro. The results of the cell cycle, apoptosis, real-time PCR, and western blotting test on MDA-MB-231 cells revealed antitumor effect of GNSs-MTX@CD-Pol NPs caused by combination Chemo-Photothermal Therapy. Based on their high stability and excellent biocompatibility, GNSs-MTX@CD-Pol NPs have great potential for the treatment of various types of tumors. [ABSTRACT FROM AUTHOR]