Fabrication of quantum dot-embedded citrus pectin nanoparticles for targeted theranostic applications in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by rapid tumor progression, high recurrence rates, and limited treatment options due to the absence of estrogen, progesterone, and HER2 receptors. Consequently, chemotherapy remains the primary therapeutic strategy; however, its clinical utility is often constrained by systemic toxicity and the emergence of drug resistance. To address these challenges, a nanoparticle-based theranostic platform was developed for simultaneous targeted drug delivery and bioimaging. In this study, pectin extracted from orange peel was employed as a biodegradable polymer and subjected to partial de-esterification to increase the exposure of galactose-rich residues, thereby enhancing its affinity toward galectin receptors overexpressed on TNBC cells. Ti₃C₂Tₓ MXene quantum dots were synthesized through selective etching followed by hydrothermal treatment and subsequently incorporated into cisplatin-loaded modified pectin nanoparticles using the ionic gelation technique. The formulated nanoparticles were comprehensively characterized by FTIR, UV-Visible spectroscopy, fluorescence spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, particle size analysis, zeta potential measurement, and in vitro drug release studies. The results confirmed the successful fabrication of stable nanosized particles exhibiting distinct fluorescence properties suitable for imaging applications. Drug release studies demonstrated a sustained and pH-responsive release profile, with enhanced cisplatin release under acidic conditions mimicking the tumor microenvironment. Furthermore, in vitro evaluation using 4 T1 breast cancer cells revealed significantly improved anticancer activity of the nanoparticle formulation compared with free cisplatin. These findings indicate that MXene quantum dot-embedded modified pectin nanoparticles represent a promising theranostic system for targeted TNBC treatment.