Mesoporous silica nanoparticle-mediated delivery of doxorubicin and withaferin A suppresses tumour growth and angiogenesis in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-related mortality, and new therapeutic strategies are required to improve anti-tumour efficacy while reducing systemic toxicity. Doxorubicin is an effective anthracycline chemotherapeutic agent, but its clinical application is limited by non-specific biodistribution and dose-limiting toxicity. Withaferin A (WFA), a bioactive withanolide, has reported anti-cancer and anti-angiogenic properties, but its therapeutic translation is limited by poor aqueous solubility. In this study, mesoporous silica nanoparticles (MSNs) were investigated as a delivery platform for doxorubicin, WFA and combined doxorubicin/WFA treatment in NSCLC models using the NCI-H358 cell line. Cellular uptake and intracellular localisation were assessed by fluorescence microscopy, while anti-tumour activity was evaluated using resazurin-based viability assays, scratch wound migration assays, 3D spheroid models and the chick chorioallantoic membrane (CAM) tumour model. Potential mechanisms of action were explored using apoptosis- and angiogenesis-focused antibody microarrays. Doxorubicin-loaded nanoparticles showed time-dependent intracellular fluorescence and reduced H358 cell viability more effectively than free doxorubicin at higher concentrations. WFA-loaded nanoparticles reduced cell viability, although nanoparticle encapsulation did not significantly enhance this effect under the conditions tested. Combination doxorubicin/WFA-loaded nanoparticles reduced cell viability in a concentration-dependent manner and significantly impaired H358 migration. In 3D spheroid models, doxorubicin, WFA and combined doxorubicin/WFA treatments reduced spheroid size over seven days, with the greatest reduction observed following combination-loaded nanoparticle treatment. In the CAM model, doxorubicin, WFA and combined doxorubicin/WFA treatments significantly suppressed tumour growth, with nanoparticle-loaded formulations also reducing tumour area compared with nanoparticle controls. Antibody microarray analysis suggested modulation of apoptosis-associated proteins and reduced expression of angiogenesis-associated markers, particularly following combination nanoparticle treatment. Together, these findings support MSN-mediated delivery of doxorubicin and WFA as a promising multi-targeted strategy for suppressing NSCLC tumour growth, migration and angiogenesis.