Researchers in the USA have developed an injectable, ‘toothpaste-like’ biomaterial that may offer promise in the treatment of intracranial aneurysms as an alternative to endovascular coil placement, surgical clipping procedures or injected liquid blocking agents—all of which carry possible downsides.
A collaborative team including scientists from the Terasaki Institute for Biomedical Innovation (TIBI) has developed an injectable shear-thinning hydrogel (STH) that exhibits enhanced cohesive strength, resisting fragmentation, even when subjected to strong, pulsating liquid flows found within the body. These shear-thinning materials behave like toothpaste in that, when force is applied, they act like a solution, but when the force is removed, they retain their structure. Previous versions of STHs underwent fragmentation and even disintegration when subjected to the high fluidic flow rates in a real-life aneurysm, a TIBI press release states.
The research team began by formulating a gelatin-based STH with nanoparticles added for reinforcement of shear-thinning capabilities, mechanical stiffness and physiological stability. They also added a highly charged chemical to the mix in order to impart cohesion without sacrificing injectability.
In an experimental study, this cohesive biomaterial was successfully injected using a neuroendovascular catheter and retained without fragmentation in patient-derived, 3D-printed cerebral aneurysm models under a physiologically relevant pulsatile fluid flow, which would not have been possible with a non-cohesive hydrogel counterpart, according to the researchers.
Testing the STH-filled vessels under constant and pulsating buffer flows for up to four days, the researchers were able to observe and quantify retention of the STH plugs. They found that the plugs had successful retention without fragmentation within the simulated blood vessels, while maintaining injectability and shear-thinning properties.
Further tests revealed that their STH caused no cellular damage and no red blood cell lysis occurred, demonstrating its safe usage for the treatment of vascular conditions, the release continues. As such, the researchers claim that it holds the potential to enable complex, minimally invasive procedures under flow.
“This improved shear-thinning hydrogel can withstand the real-life pulsating flows of the body and offers a significant advancement in treating critical vascular conditions,” said Ali Khademhosseini, TIBI’s director and CEO, and corresponding author of a paper published in ACS Applied Materials & Interfaces that details these findings. “It can pave the way for developing the next generation of injectable biomaterials.”
