Cellulose Enables Printing Antimicrobial Surgical Tools

In order to establish a more sustainable material for 3D printing, researchers from MIT have recently developed a new process using cellulose acetate.

Now that 3D printing has become an established method in our industry, scientists can further dip into this topic by improving the existing techniques. Especially when it comes to materials, they see great potential and so they seek for substances that are stronger, more efficient or more sustainable. The latter is the approach of the Massachusetts Institute of Technology (MIT) and its new 3D printing process with cellulose.

Cellulose, an Institution in the Printing Industry

Their aim? Replacing the non-renewable plastics commonly used in the 3D printing industry with a more eco-friendly material. Their secret ingredient? Cellulose! As the main component of plant cell walls, it is a widely available material, which has a long tradition in the printing sector. After all, it serves as the basis of paper, the world’s most often printed on material. Besides its easy accessibility, it is also much less expensive than other polymer materials used for 3D printing.

To be honest: The researchers around MIT Mechanosynthesis Group head A. John Hart and MIT postdoc Sebastian Pattinson are not the first to take cellulose into consideration as a 3D printing material – it has even been under discussion as a possible component of 3D-printed food. But there has always been a major challenge: Cellulose thermally decomposes when heated and due to its intermolecular bonding high-concentration cellulose solutions are too sticky for 3D extrusion.

Tackling the Challenges of Cellulose

By obtaining cellulose acetate, the team finally succeeded in overcoming these hurdles. And this is how: They combined cellulose with acetic anhydride to reduce the number of hydrogen bonds. Therefore, the scientists dissolved the cellulose in acetone. Then, the solution was extruded through a nozzle. After the acetone evaporated, the cellulose acetate solidified and made up a strong plastic alternative that can be used at room temperature. Thanks to a treatment with sodium hydroxide after the printing process, the researchers were able to restore the hydrogen bonding network and increase the strength of the printed parts.

Cellulose Acetate and Antimicrobial Dye to Build a Two in One Surgical Tool

But this is not at all how the story ends. Hart and Pattison further experimented with the material by adding an antimicrobial dye to the cellulose acetate. When they printed a pair of surgical tweezers and let fluorescent light shine on them, their antimicrobial properties activated and killed bacteria. Surgical tools that are printed in this way

“could be useful for remote medical settings where there’s a need for surgical tools but it’s difficult to deliver new tools as they break, or where there’s a need for customized tools,”

says Pattinson.

“And with the antimicrobial properties, if the sterility of the operating room is not ideal the antimicrobial function could be essential.”

On their findings, the scientists published the study “Additive Manufacturing of Cellulosic Materials With Robust Mechanics and Antimicrobial Functionality

You see, the development of cellulose acetate does not only mean a revolution in the 3D printing industry but also in the medical sector. Where else could this new process push forward new ideas?