3D Printing Creates Silk Micro-Rockets

A new 3D printing method can create tiny self-propelling strands of silk that may one day be used for cancer diagnostics and even drug delivery.

Mobile, biocompatible devices are of great interest to medical researchers and the pharmaceutical industry as a way to deliver small doses of drugs directly into tissue. Micro-rockets are tiny tubular devices that use catalytic reactions to propel themselves through fluid. In theory, these swimmers would be useful in medicine, but so far, making them has required complicated and expensive processes. And, the devices often rely on catalysts such as platinum that are not biodegradable — so they do not harmlessly dissolve in the body once their job is done.

Now, a Univ. of Sheffield research team led by biochemical engineer Xiubo Zhao and chemist Stephen Ebbens has developed a 3D-printing technique to create micro-rockets out of biocompatible, biodegradable silk, a material already approved by the U.S. Food and Drug Administration (FDA) for medical use.

The micro-rockets contain catalase tucked into a silk structure. Hydrogen peroxide acts as a fuel; catalase decomposes the hydrogen peroxide into water and oxygen, creating bubbles that propel the micro-rockets along.