Figure 4From: An improved 3D tetraculture system mimicking the cellular organisation at the alveolar barrier to study the potential toxic effects of particles on the lung Colonies of differentiated THP- 1 cells and HMC -1 cells on top of epithelial A549 cells. A: Brightfield image of THP-1 cells and HMC-1 cells that form colonies on top of A549 epithelial cells. The red arrow indicates a representative colony. B: Same transwell insert cultivated at the ALI without showing colonies. (Magnification: 200x).Back to article page