Microfluidic-Based Immunomodulation of Immune Cells Using Upconversion Nanoparticles in Simulated Blood Vessel–Tumor System

The goal of cancer immunotherapy is the selective killing of malignant cells by the cooperated efforts of immune cells at the primary and secondary sites. Here, we developed folic acid and secondary lymphoid tissue chemokine-loaded mesoporous silica-modified upconversion nanoparticle construct as a targeting, delivery, and imaging system to attract immune cells to folate receptor-expressing tumor cells. The effectiveness of the nanoparticles in targeting dendritic cells and T cells to the tumor compartment was tested in a vasculature-tumor interface model constructed from the co-culture of endothelial cells and ovarian cancer cells, in different interconnected channels in a microfluidic device. In comparison to the unconjugated nanoparticles, the folic acid-conjugated nanoparticles efficiently diffuse across the engineered blood vessel and specifically target the folate receptor-expressing ovarian cancer cells. The developed microfluidic platform was further used to demonstrate increased dendritic cell and T cell migration toward the ovarian cancer cell channel induced by the presence of the chemokine- and folic acid-loaded nanoparticles. The nanoparticle construct did not exhibit any significant cyto- and hemotoxicity. This proof of concept showed the potential of the nanoparticles to target cancer cells as well as to recruit dendritic cells and T cells to tumor sites to augment the weak host immune response.