Inkjets could yield "smart" bandages.

• Position: Biosensing

Silk inks containing enzymes, antibiotics, antibodies, nanoparticles, and growth factors could turn inkjet printing into a new, more effective tool for therapeutics, regenerative medicine, and biosensing, according to research published in Advanced Materials.

Inkjet printing is one of the most immediate and accessible forms of printing technology currently available, assert the researchers, and inkjet printing of biomolecules previously has been proposed by scientists. However, the heat-sensitive nature of these unstable compounds means printed materials rapidly lose functionality, limiting their use.

Enter purified silk protein, or fibroin, which offers intrinsic strength and protective properties that make it well-suited for a range of biomedical and optoelectronic applications. This natural polymer is an ideal "cocoon" that can stabilize compounds such as enzymes, antibodies, and growth factors while lending itself to many different mechanically robust formats, points out engineer and coauthor Fiorenzo Omenetto.

"We thought that if we were able to develop an inkjet-printable silk solution, we would have a universal building block to generate multiple functional printed formats that could lead to a wide variety of applications in which inks remain active over time."

By using this simple approach and starting with the same base material, the research team created and tested a "custom library" of inkjet-printable, functional silk inks doped with a variety of components:

* Bacterial-sensing polydiacetylenes (PDAs) printed on surgical gloves; the...