Drug delivery

Nanoparticles that target tumors and promote tumor cell phagocytosis could be used to treat cancer. The nanoparticles consisted of carboxylated polystyrene with two components conjugated to their surfaces: mAbs targeting tumor antigens, and calreticulin (CALR) to promote phagocytosis of nanoparticle-bound tumor cells by antigen presenting cells (APCs). In co-cultures of human macrophage and breast cancer cell lines, the nanoparticles conjugated to Herceptin trastuzumab and CALR increased macrophage phagocytosis of the cancer cells compared with unconjugated nanoparticles plus the free mAb and CALR. In four mouse models of breast cancer, intratumoral injection of nanoparticles conjugated to a mouse anti-HER2 mAb and CALR decreased tumor growth. Next steps could include developing and testing antibodies conjugated to other tumor-targeting mAbs in animal models of cancer...