Researchers Find Silk Matrix to be Potentially Superior as 3D Printing Bio-Ink

The medical world is one always attuned to looking into the future for better answers for improving and saving lives. While the layperson usually only has a general idea of what may be possible, we have all been aware for quite some time of–and many are involved in– a larger global conversation regarding the use of stem cells, possibilities for cloning, and many hopes for ‘cures’ for cancer and other insidious diseases. For most of us, actual solutions can seem very faraway and complex.

As the motivation to live longer–and better–drives our society on many levels, most of us of course rely on the medical and scientific community to solve the complex issues. Who knew that it would sound as simple as researchers and medical professionals designing what they want and then printing it out? That is essentially exactly what is happening–via some extremely complex research and harnessing of some of the most brilliant minds of our time in the areas of science, technology, and medicine.

As 3D printed prosthetics, implants, and a long list of devices are already almost becoming common, bioprinting is a term being commonly bandied about as the next great thing–and indeed the process will lead to the eventuality of our being able to fabricate replacement body parts, and much more.

The 3D printing of cells and the manipulation of their complex structures has been widely documented recently as researchers have been working successfully to produce items such as 3D printed glands, breast cancer tissue, and more–and look toward a world of other developments all founded on being able to 3D print from cellular structures.

Researchers who’ve recently reported in the ACS Biomaterials Science & Engineering journal have found a new material that may push bioprinting further, and faster. In their article, ‘Polyol-Silk Bioink Formulations as Two-Part Room-Temperature Curable Materials for 3D Printing,’ by Rod R. Jose, Joseph E. Brown, Katherine E. Polido, Fiorenzo G. Omenetto, and David L. Kaplan (of the Biomedical Engineering Department at Tufts University) also recognized that materials–bio-ink specifically–and the lack thereof was the hurdle to making further progress in the 3D printing of items such as bone, organs, and more. Harkening back to one of the most ancient and precious materials, they are looking at silk as a way to solve the problem and allow for scientists to continue on their way to making breakthroughs.

3D printing with silk biogels

In a chemical process involving diluting silk solutions with polyols (also known as sugar alcohols, commonly used in food) that are nontoxic, the researchers were able to create formulas with ‘self-curing’ features. They found, through experimentation, that the silk matrix indeed could perform as a 3D printing material as they fine-tuned the self-curing process. Because this allows for structure and support, and wouldn’t require further processing like other chemical substances, the researchers see it as having potential in ‘tissue engineering’ as well as production of 3D printed implants.

The ink the researchers have been able to produce is clear and flexible, maintains stability in water, and offers superior potential over other materials like thermoplastics, silicones, collagen and gelatin, or alginate. With the goal being to avoid processing which is harmful to the cells they are trying to work with, silk protein is a potentially good alternative as they could avoid the use of high temperatures and pH changes.

Equipment and materials obviously play a big part in this push for bioprinting. We have the concepts and some working examples, but what researchers actually have to work with in the process can be challenging as we’ve reported previously regarding those polled on bioprinting processes and levels of satisfaction. With a process that is obviously in its beginning stages, scientists don’t have a large foundation to work from in bioprinting–instead, they are the ones responsible for building one, through trial and error. And many find current bioprinting materials–and methods–to be limiting.

The latest work by Kaplan and his colleagues sounds like a possible to answer to solving some of the challenges that must be overcome in the bioprinting arena, and we look forward to following further progress as they work with silk as a medium.

What are your thoughts on silk as a potential material in bioprinting? Is this an area of 3D printing that interests you, and if so, why? Discuss in the Silk 3D Printing Bio-Ink forum thread over at 3DPB.com.