Brown University engineers have developed a technology that can be used to create 3D printed biomaterials that “degrade on demand”. This material can be used to make complex microfluidic devices or dynamic cell cultures. The ability to degrade on demand is associated with a particular chemical trigger. In addition, in the material manufacturing process, researchers also used a stereolithography technique to fabricate 3D printed structures with potentially reversible ionic bonds.

No one has ever used SLA 3D printers to do this. In order to figure out how to do this, the researchers used alginate to make a solution. Alginate is a complex from seaweed that is capable of ion crosslinking.

By using different combinations of ionic salts, including magnesium, barium and calcium, Brown University researchers create 3D printed objects with different levels of stiffness, which is a factor influencing the rate of structural dissolution.

"Our idea is that when the ions are removed, the connections between the polymers should be broken. By adding a chelating agent that traps all the ions, we can remove the ions," the researchers explained. "This way, we can Combine transient structures that will disintegrate when we need them."

So, what is the use of this 3D printing structure that can degrade on demand? In this regard, the researchers have several ideas.

On the one hand, alginate can be used as a template to make laboratory equipment on a chip with complex microfluidic channels. “We can use alginate to print the shape of the channel and then use another biomaterial around it to print a permanent structure,” the researchers explained. “Then we simply dissolve the alginate, so we get A hollow channel without any cutting or complicated assembly."

This stereolithography can also be used to create dynamic environments for live cell experiments. Specifically, the alginate barrier is surrounded by human breast cells, and when the barrier is dissolved, the cells migrate in a specific manner. This can contribute to cancer research as well as the manufacture of artificial tissues and organs, because the alginate barrier is not toxic to human cells.

“We can start thinking about using this method in artificial tissue. In artificial tissue, you may want to have a blood vessel-like channel,” the researchers said. “We can use alginate to simulate the vasculature and then alginic acid. The salt is dissolved."

Now, the researchers plan to continue researching the project to better control the stiffness, strength and degradation rate of the printed structure. This research has been published on Lab on a Chip.