Tumor microenvironment-responsive diagnosis and treatment of integrated drug-loaded CdTe quantum dots for treatment tumors

Abstract The acidic tumor microenvironment is a common feature of tumors, and boric acid-functionalized quantum dots (BA-QDs) exhibit pH-sensitive boron affinity effects and fluorescence emission characteristics. In this study, CdCl2·2.5H2O was used as the cadmium source, whereas NaTeO3 was used as the tellurium source. CdTe quantum dots (QDs) were prepared using the water phase synthesis method. Additionally, BA-QDs) were prepared by modifying QDs with 4-mercaptophenylboric acid (4-MPBA). Hesperetin, baicalein, quercetin, and other model drugs were used, with QDs and BA-QDs serving as carriers, to create a drug-loaded system of QDs with tumor microenvironment-responsive drug release performance. The physical and chemical properties were characterized by performing nanoparticle size analysis (DLS), Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), etc. Our findings showed that the synthesis of drug-loaded QDs with a uniform particle size was successful. The experiments involved studying the adsorption kinetics of the QDs and the degree of dissolution of the drug-loaded QDs in vitro. BA-QDs exhibited pH-responsive drug release and fluorescence emission properties. In vitro cell experiments were conducted to examine the uptake and imaging effects of QDs and BA-QDs at the cell level. The results showed that both QDs and BA-QDs exhibited effective imaging at the cell level. Moreover, the three drug-loaded BA-QDs inhibited HepG2 cancer cells by about 80%, indicating a significant inhibitory effect on cancer cells. Here, we developed a universal new technology for tumor diagnosis and treatment, provided innovative approaches for targeted cancer diagnosis and treatment, and broadened the application scope of nanofluorescence technology.