Cy5.5-MSA-G250 nanoparticles (CMGNPs) induce M1 polarity of RAW264. 7 macrophage cells via TLR4-dependent manner

Cy5.5-MSA-G250 nanoparticles (CMGNPs) had been proved to have unique advantages for cancer treatment, including excellent photothermal performance, tumor cell-selective cytotoxicity, direct visualization, and good biocompatibility. However, to cellular systems, the CMGNPs are considered as foreign invaders, and the effect of CMGNPs on immunity system is still unknown. Therefore, more efforts are needed to understand the role of CMGNPs on the immunity system. In this study, we attempted to screen the pro-inflammatory responses on RAW264.7 macrophages after treated with the CMGNPs. In vitro experiments clearly showed that CMGNPs not only enhances phagocytosis capacity of RAW264.7 cells, but also promotes M1 polarization, associated with changes in cell morphology and increased expression of inflammatory cytokines. This ability to induce M1 polarization may be beneficial to CMGNPs to achieve better anticancer effects in clinical trials. Moreover, the observed M1 macrophages' polarization triggered by CMGNPs can be abolished after adding TLR4 inhibitor, CLI095, suggesting that TLR4 is involved in CMGNP-induced inflammation.