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

<b>Background/Objectives:</b> 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. <b>Methods:</b> 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. <b>Results:</b> 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. <b>Conclusions:</b> Our findings establish a nanotechnology-enabled approach to potentiate cisplatin efficacy by simultaneously countering chemoresistance mechanisms and metastatic pathways in NSCLC management.