3D printed scaffolds helping with the study of bone cancer
Scientists have made 3D printed scaffolds to help them better understand bone cancer tumours. Researchers at Rice University in Houston, Texas, used the bone-like structure to investigate how Ewing's sarcoma cells respond to different stimuli, such as shear stress. They found that the overall scaffold porosity, and the shape and size of the pores, had a significant effect on how cancer cells spread throughout bone, according to the study published in ACS Biomaterials Science. The scientists, led by bioengineer Antonios Mikos, believe the model could be used to study possible treatments for bone cancer. 

Feb 9, 2017

Scientists at Rice University in Houston have used 3D printing to create porous, bone-like scaffolds that can be used to study bone cancer tumors. They found that the size and orientation of individual pores affected how cells proliferate in the absence of blood.

Researchers at Rice University have determined that the tiny holes within our bones have a significant effect on how cancerous cells operate and spread. Led by bioengineer Antonios Mikos, the scientists used a 3D printed scaffold to see how Ewing’s sarcoma (bone cancer) cells respond to stimuli such as shear stress. They discovered that the size and shape of pores, as well as overall scaffold porosity, had an impact on how cancer cells are able to spread throughout bone.

In a research project whose findings have been published in ACS Biomaterials Science and Engineering, the Rice researchers found that the size and shape of pores, in addition to the percentage of empty space in a structure created by pores, have an impact on cell attachment, the permeability of media and nutrients, and cell migration. They discovered this by creating 3D printed scaffolds that mimic the structure of bone.

According to Mikos, the 3D printed polymer bone scaffold contains artificial pores that constrain the flow of fluid and apply shear stress to tumor cells. By varying the 3D printed scaffold architecture and pore structure, he and his team were able to change the environment through which fluids flow, as well as the magnitude of shear stress. The scientists believe that this model could be vital for finding out more about bone cancer and potential treatments: “We aim to develop tumor models that can capture the complexity of tumors in vitro and can be used for drug testing, thus providing a platform for drug development while reducing the associated cost,” Mikos said.

The Rice researchers say that using a 3D printed scaffold gives a much more realistic picture of bone structure and cell behavior than using cells in a flat petri dish. After 3D printing each flat section of the scaffold with pores in one of three sizes (0.2, 0.6 and 1 mm), the researchers could stack the layers to form a scaffold, before seeding them with tumor cells. A flow perfusion reactor was then used to mimic the push and pull of fluids and tissues in a biological environment.

Use of the flow perfusion reactor produced interesting results. The researchers noted that cells proliferated with greater efficiency when under flow. Additionally, once fluid began to flow, layers with the smallest pores showed significantly more proliferation. Cells also increased their production of insulin-like growth factor protein (IGF-1), a ligand on the surface of sarcoma cells and a significant obstacle to successful chemotherapy treatment. The scientists also found that pore orientation had an effect on how much IGF-1 the cells produced.

The Rice team believes that the combination of shear stress and scaffold orientation prompted different levels of protein production, and the researchers now plan to continue their research project in order to study metastasis and test the efficacy of different drugs for fighting cells. The Rice scientists’ research paper concludes: “Our results highlight how 3D printed scaffolds, in combination with flow perfusion in vitro, can effectively model aspects of solid tumor heterogeneity for future drug testing and customized patient therapies.”

Posted in 3D Printing Application