Dual-Action Tocilizumab-Conjugated Cisplatin Nanoparticles Overcome Chemoresistance and Metastasis in Non-Small-Cell Lung Cancer

Abstract

Background/Objectives: Cisplatin remains a cornerstone chemotherapeutic agent for non-small-cell lung cancer (NSCLC) treatment, yet its clinical utility is substantially limited by acquired resistance and the inadequate suppression of tumor metastasis. Emerging evidence implicates interleukin 6 (IL-6) as a critical mediator of chemoresistance through cancer stem cell (CSC) enrichment and metastasis promotion via epithelial–mesenchymal transition (EMT) induction, ultimately contributing to cisplatin therapy failure. This study sought to address these challenges by designing a nanoplatform with two innovative aims: (1) to achieve active tumor targeting through binding to the IL-6 receptor (IL-6R), and (2) to concurrently inhibit IL-6-mediated chemoresistance signaling pathways. Methods: A lipid–polymer hybrid nanoparticle (LPC) encapsulating cisplatin was synthesized and subsequently surface-functionalized with tocilizumab (TCZ), a monoclonal antibody that targets IL-6R. The therapeutic efficacy of this TCZ-modified nanoparticle (LPC-TCZ) was assessed through a series of in vitro and in vivo experiments, focusing on the inhibition of EMT, expression of CSC markers, tumor growth, and metastasis. Results: Systematic in vitro and in vivo evaluations revealed that LPC-TCZ synergistically attenuated both EMT progression and CSC marker expression through the targeted blockade of IL-6/STAT3 signaling. This multimodal therapeutic strategy demonstrated superior tumor growth inhibition and metastatic suppression compared to conventional cisplatin monotherapy. Conclusions: Our findings establish a nanotechnology-enabled approach to potentiate cisplatin efficacy by simultaneously countering chemoresistance mechanisms and metastatic pathways in NSCLC management.