The Effects of Methylene Blue and Carbon Nanoparticles on Transplanted Lymph Node Survival, Reconstructed Lymphatic Function, and Changes in Inflammatory and Fibrosis Factors.

ABSTRACT

BACKGROUND AND OBJECTIVES: Methylene blue (MB) and carbon nanoparticles (CNs) can be used as a simple method for reverse lymphatic mapping. We investigated whether the two tracers had an impact on the survival of lymph nodes and the function of reconstructed lymph vessels after transplantation, as well as the changes in surrounding related factors. METHODS: The stained lymph nodes were non-vascularized transplanted into the contralateral popliteal fossa in mice. After 4 weeks, the lymphatic recanalization was detected. The samples were harvested for pathological detection and PCR. In addition, the transport ability of the recanalized lymphatics to tumor cells was also explored. RESULTS: Compared with the control group, there was no significant difference of the MB and CNs groups in the drainage function of recanalized lymphatic vessels, the survival of lymph nodes, or the transport capacity to tumor cells. TNF-α and IL-6 were significantly higher in the two tracer groups (**p < 0.01). Besides, the α-SMA was significantly increased in the CNs group (*p < 0.05). CONCLUSIONS: Two tracers have no effect on the survival of transplanted lymph nodes, nor do they affect the drainage ability or tumor cell capture ability of the reconstructed lymphatics, despite improving TNF-α and IL-6 levels and the deposition of CNs.