Nanoparticles capable of navigating macrophages to tumors for magnetic resonance imaging and treatment of ultra small pulmonary metastasis

Motivation: Pulmonary metastasis is a major cause of cancer-related mortality, with the detection of ultra-small metastatic lesions remaining a significant challenge. Goal(s): This study aims to develop an innovative MRI contrast agent (CaCO3@quercetin-Mn nanoparticles, CQM NPs) for the early detection and therapeutic intervention of pulmonary metastasis via macrophage-mediated delivery. Approach: CQM NPs were designed to polarize and direct macrophages to metastatic sites, enabling precise and effective delivery to pulmonary metastases. Results: The CQM NPs enabled MRI detection of pulmonary metastases as small as 0.23 mm and demonstrated robust inhibitory and prophylactic effects against metastatic lung tumors. Impact: CQM NPs serve as a promising MRI contrast agent for early detection and as a potential therapeutic option for pulmonary metastasis, offering hope for reducing the high mortality associated with this challenging disease.