Nanocomposite Hydrogel with Tantalum Microparticles for Rapid Endovascular Hemostasis

Abstract

Endovascular embolization to treat vascular hemorrhage involves pushing coil‐shaped metal wires into the artery repeatedly until they are densely packed to slow the blood flow and clot. However, coil embolization is associated with high rebleeding rates, unpredictable economics and, most importantly, they rely on the patient's ability to make a clot. These issues are exacerbated when the patient is anticoagulated or coagulopathic. A novel bioengineered tantalum‐loaded nanocomposite hydrogel for gel embolic material (Ta‐GEM) that can be rapidly delivered using clinical catheters for instant hemostasis regardless of the coagulopathic state is reported. Ta‐GEM formulation is visible by most of the clinically available imaging modalities including ultrasound, computed tomography, magnetic resonance imaging, and fluoroscopy without significant artifact. In addition, Ta‐GEM can be retrieved, allowing temporary vascular occlusion, and it can be used to rescue cases of failed coil embolization. Ta‐GEM occlusion of first‐order arteries such as the renal artery and iliac artery in a swine model is found to be safe and durable; by 28 days, 75% of the injected Ta‐GEM in the arterial lumen is replaced by dense connective tissue. Altogether, this study demonstrates that Ta‐GEM has many advantages over the current technologies and has potential applications in clinical practice.

Embolic Materials: Understanding the Ocean of Choices

“…It becomes a liquid when pressure is applied but forms a solid when that pressure is removed (after leaving the catheter), it has shown promise in preclinical studies. 56…”

A Versatile Crosslinking Strategy on Facile Fabrication of Fluorescent Hydrogels via o‐Phthalaldehyde Ternary Condensation

“…Hydrogels are soft and wet materials that are crosslinked through physical interaction or chemical bonding. [ 1‐3 ] For decades, high‐efficient chemical crosslinking has been manipulated and applied to construct the covalent hydrogel networks such as oxime ligation, [ 4 ] azide‐alkyne cycloadditions [ 5 ] and anthracene dimerization, [ 6 ] which have broad application prospects in cell encapsulation, tissue engineering, drug delivery and wound closure. [ 4‐10 ] However, these crosslinking strategies generally require additional reaction conditions such as catalysts, heat, or light, [ 11‐12 ] resulting in a relatively complex gelation process and residual additives.…”

Graphene Quantum Dots for Fluorescent Labeling of Gelatin‐Based Shear‐Thinning Hydrogels

“…Several imaging techniques, including magnetic resonance imaging (MRI) with high spatial resolution, [ 21–24 ] ultrasound imaging, [ 25,26 ] nuclear imaging, [ 27 ] fluorescence imaging, [ 20,28–31 ] and a combination of these techniques, [ 32,33 ] have been suggested for noninvasive monitoring of hydrogels in vivo. For example, Albadawi et al prepared an injectable embolic hydrogel loaded with tantalum.…”

“…For example, Albadawi et al prepared an injectable embolic hydrogel loaded with tantalum. [ 33 ] The tantalum served as an imaging agent to visualize fragmentation or migration of the hydrogel using a combination of MRI, ultrasound, and computed tomography techniques. However, the application of MRI and ultrasound techniques in imaging is limited by their low sensitivity and complicated instruments.…”

“…Considering demonstrated medical applications of our developed gelatin‐based STB particularly in endovascular hemostasis, real‐time monitoring of hydrogel is a critical need to prevent nontarget embolization. [ 14,18,33 ] To the best of our knowledge, there is no report on fluorescence in vivo monitoring of injectable gelatin‐based STBs using fluorophore GQDs. In this work, GQDs are integrated within our gelatin‐based STB, enabling real‐time monitoring and tracking of STBs through noninvasive fluorescence imaging.…”