Construction of Graphene Oxide Probes Loaded with Antisense Peptide Nucleic Acid and Doxorubicin for Regulating Telomerase Activity and Inducing Apoptosis of Cancer Cells.

In this study, we developed a multifunctional graphene oxide (GO)-based nanoprobe co-loaded with antisense peptide nucleic acid (PNA) and the chemotherapeutic agent doxorubicin (DOX). The nanoplatform was strategically functionalized with folic acid ligands to enable folate receptor-mediated tumor targeting. Upon cellular internalization, the antisense PNA component selectively hybridized with human telomerase reverse transcriptase (hTERT) mRNA through sequence-specific recognition, inducing structural detachment from the GO surface. This displacement restored the fluorescence signal of previously quenched fluorophores conjugated to the PNA strand, thereby enabling the real-time in situ detection and quantitative fluorescence imaging of intracellular hTERT mRNA dynamics. The antisense PNA component effectively reduced the hTERT mRNA level and downregulated telomerase activity via an antisense gene regulation pathway, while the pH-responsive release of DOX induced potent cancer cell apoptosis through chemotherapeutic action. This combinatorial therapeutic strategy demonstrated enhanced anticancer efficacy compared to single-modality treatments, achieving a 60% apoptosis induction in HeLa cells through coordinated gene silencing and chemotherapy. This study establishes GO as a promising dual-drug nanocarrier platform for developing next-generation theranostic systems that integrate molecular diagnostics with multimodal cancer therapy.