When removing pre-cancerous polyps from the colon, physicians typically inject saline into the tissue below the polyps to raise them and make them easier to access. However, saline drains away quickly, requiring precise timing and repeat injections, among other difficulties.
Now, scientists at MIT have developed an injectable material that can be used to create these “cushions” below polyps, but that stays in place much longer than plain saline.
The nifty aspect of the new material is that it starts out as liquid, but quickly transitions into a solid post injection. “That really makes a huge difference to the gastroenterologist who is performing the procedure, to ensure that there’s a stable area that they can then resect using endoscopic tools,” said Giovanni Traverso, the lead of the team that developed the material.
What the team created was a shear-thinning gel that is naturally stiff, but when squeezed through a needle it becomes a liquid until it exits the needle and turns back to a stiff gel.
The gel consists of laponite, a clay already used in various products, and alginate, a sugar derived from algae. The two compounds are biocompatible and the combination results in just the right strength when stiff and the correct viscosity when pushed through a needle.
The researchers have also created a framework allowing others to create variations of their material, with different viscosities and other characteristics.
Study in journal Advanced Science: Endoscopically Injectable Shear‐Thinning Hydrogels Facilitating Polyp Removal