Scientists from Rice University in Texas have used 3D printing technology to create enhanced support structures that mimic the biological environment of bone cancer tumours.
Using the technology has allowed the researchers to simplify test treatments and learn how tumours multiply so rapidly.
Antonios Mikos, a Rice bioengineer, led the team as they worked to enhance its 3D-printed scaffold to see how bone cancer cells respond to stimuli. Particularly exploring cell response to shear stress, the force experienced by tumours as viscous fluid such as blood flows through bone, the researchers determined the structure of a scaffold has a very real effect on how cells express signalling proteins that help cancer grow.
According to the researchers, the size and shape of pores and scaffold porosity can impact cell attachment, alter the permeability of media and nutrients and facilitate cell migration. 3D printing has enabled them to get closer than ever to mimicking the architecture of real bone. The scaffold’s bone-like printed polymer contains pores of varying sizes to constrain fluids that flow through and apply varying degrees of shear stress to the tumour cells, depending on the scaffold’s orientation in relation to the flow.
“We aim to develop tumour models that can capture the complexity of tumours in vitro and can be used for drug testing, thus providing a platform for drug development while reducing the associated cost,” Mikos said.
Three layers of scaffold, in three different sizes of 0.2, 0.6 and 1 millimetre, were stacked to make each 3D scaffold. These were then seeded with tumour cells and placed in a flow perfusion reactor that mimics the push and pull of fluids and tissues in a biological environment. The result is a much more realistic simulation than growing cells in a flat petri dish.
Rice’s researchers found that cells proliferated far better under flow than in conditions without fluid flow. When fluid was flowing, layers with the smallest pores showed significantly more proliferation. They also found that under flow, cells tended to increase their production of insulin-like growth factor protein, which is part of the signalling pathway that plays a critical role in resistance to chemotherapy.
Moving forward, the researchers plan to refine their scaffold-printing process to study metastasis and test tumours’ response to drugs.
The research is detailed in the American Chemical Society journal, ACS Biomaterials Science and Engineering. Among the supporters of the research were the National Institutes of Health, the Armed Forces Institute of Regenerative Medicine, the National Science Foundation and the Howard Hughes Medical Institute supported the research.