Impact of Tumor Barriers on Nanoparticle Delivery to Macrophages

The delivery of therapeutic nanoparticles to target cells is critical to their effectiveness. Here we quantified the impactof biological barriers on the delivery of nanoparticles to macrophages in two different tissues. We compared the delivery of goldnanoparticles to macrophages in the liver versus those in the tumor. We found that nanoparticle delivery to macrophages in thetumor was 75% less than to macrophages in the liver due to structural barriers. The tumor-associated macrophages took up morenanoparticles than Kupffer cells in the absence of barriers. Our results highlight the impact of biological barriers on nanoparticledelivery to cellular targets