Development of a quadruple-conjugated carbon dot nanomodel for targeted glioma therapy

High-grade gliomas are devastating cancers with dismal prognosis, largely because current chemotherapeutics fail to cross the blood-brain barrier and lack tumor-cell specificity. Nanotechnology aims to overcome these limitations through targeted drug delivery. Here, a quadruple-conjugated nanomodel was synthesized using carbon dots (C-dots) as biocompatible nanocarriers via a one-pot reaction that covalently links two targeting peptides and two anticancer agents. The short peptide (shPep-1) targets the tumor-restricted receptor IL13Rα2, whereas the long peptide (lnPep-1) contains a nuclear localization signal for enhanced intracellular trafficking. Therapeutic cargo consists of epirubicin and the temozolomide metabolite 5-aminoimidazole-4-carboxamide. This nanomodel displays potent cytotoxicity in multiple high-grade glioma cell lines at 50 nM while remaining relatively non-toxic to normal cells (IC₅₀ > 2 µM). Despite a lower drug-loading capacity than single-peptide formulations, it induced greater glioma cell death, underscoring the enhanced therapeutic synergy of its dual-peptide, dual-drug design. Fluorescence studies confirm superior uptake and nuclear delivery, establishing C-dots as a stable, cost-effective, modular platform for next-generation personalized cancer nanotherapies.