Impact of immunomagnetic nanoparticle size on capture efficiency, bioactivity, and proliferation ability of circulating tumor cells

The application of immunomagnetic nanoparticles (IMNs) enables the isolation of rare circulating tumor cells (CTCs) from blood. Precise capture of CTCs with specific tumor phenotypes is achieved by attaching specific ligands to the surface of IMNs. The captured CTCs need to exhibit high bioactivity and proliferation ability for subsequent detection after co-culturing. The process of CTC enrichment using magnetic nanoparticles entails several issues, such as nonspecific capture and biological toxicity. Modifying the size of nanoparticles allows for altering the capture efficiency of nanoparticles for CTCs, as well as their biological activity and proliferation ability. In this study, two different sizes of magnetic nanoparticles are utilized to capture CTCs under diverse conditions. The capture efficiency of magnetic nanoparticles is assessed at different incubation times, along with determining the time needed to achieve and sustain the optimal capture efficiency. Fluorescence staining is employed to detect the bioactivity and cellular integrity of the captured CTCs. Subsequent to co-culturing with nanoparticles, the number of CTCs is measured every 24 h, and the survival rate is determined after 96 h. Graphical abstract