There are many compounds that can kill cancer cells in the petri dish, but end up falling flat when tried on real cancers in human beings. The reasons for this aren’t simple, but one of the most basic causes is that real three-dimensional tumors have different properties than a 2D layer of cultured cells in the lab. A team headed by Wei Sun from Drexel University’s College of Engineering has devised a way to 3D print spherical tumors that more closely mimic the tumors found in the human body.
To have a better idea of how cancers behave in the body, we need to factor in cell-to-cell interactions, surface area, and volume. You can’t do that very easily with a regular culture, so scientists have been searching for viable ways to build more authentic tumors for several years. Additive manufacturing has met with some success, but the super-precise 3D printer used in Sun’s lab has succeeded in making living, spherical tumors for the first time.
The printer was used to lay down layers of HeLa cells (a common cervical cancer cell line) suspended in a hydrogel support matrix. The researchers found that after a few days of growth, the cells had developed into round tumors. The technique used relies on careful control of temperature and nozzle speed to keep more than 90% of the cells alive. You can see the printer in action in the video below.
In order to prove the clinical significance of this development, Sun and his team tested a common cancer treatment on the spherical tumors, then compared that to results obtained from traditional petri dish cultures. As predicted, the drugs had less effect on the 3D printed tumors than they did on the flat cultures, indicating the shape and composition of these lab-created tumors could respond more like the real thing.
The next step is to attempt to print these tumors in other tissues to better simulate human cancers. The team might also be able to connect up 3D printed blood vessels to make the illusion more complete. This technology could essentially become a living model for cancer outside the body.