A new bio-ink made of Muga silk-proteins and live cells that can be used to 3D-print human tissue, organs or even implants at low cost has been invented by researchers at IIT Guwahati. The technology could go a long way in reducing the wide gap between patients in need of organ transplants/implants, and the dearth of healthy donors.
At the Biomaterials and Tissue Engineering Laboratory in IIT-Guwahati, Dr Biman B Mandal has been working with silk proteins to try and create an artificial implant that mimics the architecture and structure of real tissues, organs, bone, and cartilage. Mandal and his team of researchers have created prototypes of bone, cartilage, and knee-meniscus " structural tissues. Soft tissues like liver, heart and skin tissue have also been printed with the bio-ink successfully by the team, which is now awaiting patent certificate for the Muga silk protein bio-ink.
A team of Muga silkworms on a tree. Image: Wikimedia Commons
"Bioprinting has come a long way¦ We are now able to recreate minute architecture down to the micron level, which conventional methods were not able to do before," Mandal told Northeast Today.
To begin with, a virtual 3D model of the organ/implant is constructed using MRI and CT scans to match the patient's exact requirement. The Muga silk bio-ink is then incorporated with stem cells from the patient before the artificial tissue is printed. The tissue or organ is then matured in a laboratory (the stem cells are programmed to specialize/differentiate and form all the different cell types in an organ/tissue) before it is implanted to take the place of a defective body part.
Once implanted, the mature stem cells in the 3D printed patch continue to grow and proliferate, Meanwhile, the silk protein degrades into amino acids, facilitating the regrowth of damaged parts of the organ, Mandal said.
This technique also does away with the need for additional surgery to remove the implant.
There are two important features that a bio-ink polymer needs to have: the ability to support live cells, and the stability to keep itself and the live cells free of harm from start to end of the printing process.
"For tissue engineering applications, we are always looking for polymers which would allow the cells to stick to it, and also give a suitable space for cells to grow and proliferate faster. Generally, people use different types of polymers like collagen. Scientists use chemicals to bind cells to these polymers," he said.
Muga silk, a wild silk variety that is geographically-tagged to Assam, is known for its extreme durability and its natural yellowish-golden tint and a shimmering, glossy texture. Till a few decades ago, this silk was reserved exclusively for royalty.