Carbon nanotubes activate macrophages into a M1/M2 mixed status: recruiting naïve macrophages and supporting angiogenesis.
The potential of carbon nanotubes (CNTs) in medical applications has been attracting constant research interest as well as raising concerns related to toxicity. The immune system serves as the first line of defense against invasion. In this work, interactions of oxidized multiwalled carbon nanotubes (MWCNT) with macrophages were investigated to unravel the activation profile of macrophages, using cytokine array, ELISA assay, transwell assay, confocal microscopy, and reactive oxygen species examination. Results show that MWCNT initiate phagocytosis of macrophages and upregulate CD14, CD11b, TLR-4/MD2, and CD206, which does not alter the MHCII expression of the macrophages. The macrophages engulfing MWCNT (MWCNT-RAW) secrete a large amount of MIP-1α and MIP-2 to recruit naïve macrophages and produce angiogenesis-related cytokines MMP-9 and VEGF, while inducing much lower levels of proinflammatory cytokines than those activated by LPS. In conclusion, MWCNT activate macrophages into a M1/M2 mixed status, which allows the cells to recruit naïve macrophages and support angiogenesis.
['Meng|Jie|J|', 'Li|Xiaojin|X|', 'Wang|Chuan|C|', 'Guo|Hua|H|', 'Liu|Jian|J|', 'Xu|Haiyan|H|']
D000818:Animals D002460:Cell Line D002478:Cells, Cultured D016207:Cytokines D008262:Macrophage Activation D008264:Macrophages D051379:Mice D049329:Nanostructures D037742:Nanotubes, Carbon D018919:Neovascularization, Physiologic D017382:Reactive Oxygen Species
carbon nanotubes recruitment angiogenesis macrophage activation phenotype