Primary Human Breast Cancer‐Associated Endothelial Cells Favor Interactions with Nanomedicines

Cancer nanomedicines predominately rely on transport processes controlled by tumor‐associated endothelial cells to deliver therapeutic and diagnostic payloads into solid tumors. While the dominant role of this class of endothelial cells for nanoparticle transport and tumor delivery is established in animal models, the translational potential in human cells needs exploration. Using primary human breast cancer as a model, the differential interactions of normal and tumor‐associated endothelial cells with clinically relevant nanomedicine formulations are explored and quantified. Primary human breast cancer‐associated endothelial cells exhibit up to ≈2 times higher nanoparticle uptake than normal human mammary microvascular endothelial cells. Super‐resolution imaging studies reveal a significantly higher intracellular vesicle number for tumor‐associated endothelial cells, indicating a substantial increase in cellular transport activities. RNA sequencing and gene expression analysis indicate the upregulation of transport‐related genes, especially motor protein genes, in tumor‐associated endothelial cells. Collectively, the results demonstrate that primary human breast cancer‐associated endothelial cells exhibit enhanced interactions with nanomedicines, suggesting a potentially significant role for these cells in nanoparticle tumor delivery in human patients. Engineering nanoparticles that leverage the translational potential of tumor‐associated endothelial cell‐mediated transport into human solid tumors may lead to the development of safer and more effective clinical cancer nanomedicines. Tumor blood vessels are barriers for nanomedicines en route to solid tumors. This study indicates that primary human breast tumor‐associated endothelial cells exhibit higher nanoparticle uptake efficiency than normal mammary microvascular endothelial cells, along with an increased number of intracellular vesicles and upregulated transport‐related genes. These findings may advance the development of safer and more effective cancer nanomedicines.