Functional roles of magnetic nanoparticles for the identification of metastatic lymph nodes in cancer patients

Abstract

Staging lymph nodes (LN) is crucial in diagnosing and treating cancer metastasis. Biotechnologies for the specific localization of metastatic lymph nodes (MLNs) have attracted significant attention to efficiently define tumor metastases. Bioimaging modalities, particularly magnetic nanoparticles (MNPs) such as iron oxide nanoparticles, have emerged as promising tools in cancer bioimaging, with great potential for use in the preoperative and intraoperative tracking of MLNs. As radiation-free magnetic resonance imaging (MRI) probes, MNPs can serve as alternative MRI contrast agents, offering improved accuracy and biological safety for nodal staging in cancer patients. Although MNPs' application is still in its initial stages, exploring their underlying mechanisms can enhance the sensitivity and multifunctionality of lymph node mapping. This review focuses on the feasibility and current application status of MNPs for imaging metastatic nodules in preclinical and clinical development. Furthermore, exploring novel and promising MNP-based strategies with controllable characteristics could lead to a more precise treatment of metastatic cancer patients.

Keywords: Bioimaging; Cancer diagnosis and treatment; Iron oxide; Magnetic nanoparticles; Metastatic lymph nodes.

Fig. 1

The application of MNPs-based strategies for MRI imaging of tumor lymphatic metastasis. The successful development of MNPs-based strategies in bioimaging recently made it possible to utilize MNPs as the MRI probes for MLNs tracking in cancer patients. After injection, MNPs could be preferentially phagocytosed by cells in normal lymphoid tissues, resulting in the darkening signal on T2*-weighted images. Inversely, high signal intensity on T2*-weighted images is observed for the metastatic LNs which do not take up the nanoparticles

Fig. 2

Schematic illustrations indicating the different types of MNPs in LN mapping. These MNPs with different physicochemical and pharmacodynamic characteristics have been successfully synthesized, and displayed the excellent diagnostic potential for identification of metastatic LNs in cancer patients

Fig. 3

The magnetic nanoagents with multifunctional capability exhibit high sensitivity for nodal staging and cancer treatment. With the rapid development of technologies, several multimodal MNPs-based contrast imaging agents have been developed for the LNs detection and cancer theranostics