Size-dependent lymphatic uptake of nanoscale-tailored particles as tumor mass increases

Abstract

Aim: To investigate the size-dependent lymphatic uptake of nanoparticles in mice with rapidly growing syngeneic tumors. Materials & methods: Mice were inoculated subcutaneously with EL4 lymphoma cells and on day 5 or day 6 of tumor growth, injected peritumorally with either 29 nm or 58 nm of ultra-small superparamagnetic iron oxide nanoparticles. Twenty-four hours later the animals were imaged using MRI. Results & conclusion: The larger of the two particles can only be detected in the lymph node when injected in animals with 6-day-old tumors while the 29 nm ultra-small superparamagnetic iron oxide nanoparticle is observed on both time points. Tumor mass greatly impacts the size of particles that are transported to the lymph nodes. This study aims to improve the way the spreading of certain forms of cancer is detected. The method, known as sentinel lymph node detection, locates and removes the first lymph node that drains the tumor to examine it for cancer cells. The authors want to improve the way this is done by using a new contrast agent based on nanoparticles. Two different sizes of particles were injected around the implanted tumors in mice and imaged with MRI. The results indicate that the mass of the tumor plays a crucial role in the transport of nanoparticles to the lymph node.