Light-sensitive hydrogel to fill brain aneurysms


Researchers at Pohang University of Science and Technology (POSTECH) in Korea have developed a new technique to treat brain aneurysms. Described in the journal Advanced Materials, treatment involves using a catheter to administer an aligned hydrogel that is crosslinked into place within the aneurysm by light. Hydrogel is not degradable and can reside inside the body for extended periods. As an alternative to coil embolization, the hydrogel stabilizes the aneurysm and reduces the chance of it exploding.

Brain aneurysms form when a weak spot comes out of a cerebral artery that puts pressure on nearby tissues. This ultimately poses a significant risk of a ship exploding, which is often fatal. Currently, doctors can treat these aneurysms by coil embolization, which aims to stabilize the aneurysm with platinum coils. The coils redirect blood flow and reduce the pressure inside the aneurysm. However, this procedure can be dangerous and can cause the boat to break. The coils can also be detached from the boat.

This new approach involves using an alginate hydrogel to embolize the aneurysm. This hydrogel must be liquid when delivered, as it must pass through a narrow catheter and then fill the aneurysm as needed, before it is semisolid and remain in place. However, in the tortuous and throbbing environment of a blood vessel, full of running blood, it can be difficult to control the behavior of the ice.

These challenges led to the mechanism underlying the latter technology, which incorporates a light-sensitive gel that rapidly undergoes a covalent crosslinking reaction when exposed to light. The catheter distribution system incorporates an optical fiber that can transmit light as the ice is extruded, allowing good control of ice deposition during the procedure. The gel is delivered in the form of microfibers that fill the aneurysm and then undergo another ionic crosslinking reaction once in place due to the presence of calcium in the blood.

The ice does not degrade through the body and therefore must remain in place for a long time. It is also possible to load it with contrast agents so that it can be imagined, both during deposition and afterwards to check if it still works properly.

“This research is the first in the world to develop a method that can be used to treat aneurysms by microfibrillating a photocrossable hydrogel microfiber into blood vessels,” said Professor Joonwon Kim, a researcher involved in the study. . “These materials are expected to be effectively applicable to many vascular diseases that require embolization.”

Study a Advanced materials: Embolization of vascular malformations by an in situ photocross bond of mechanically reinforced alginate microfibers by means of a microfluidic device integrated with optical fiber

Via: Pohang University of Science and Technology

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