Embolization of Vascular Malformations via In Situ Photocrosslinking of Mechanically Reinforced Alginate Microfibers using an Optical‐Fiber‐Integrated Microfluidic Device

Abstract

Embolization, which is a minimally invasive endovascular treatment, is a safe and effective procedure for treating vascular malformations (e.g., aneurysms). Hydrogel microfibers obtained via spatiotemporally controllable in situ photocrosslinking exhibit great potential for embolizing aneurysms. However, this process is challenging because of the absence of biocompatible and morphologically stable hydrogels and the difficulty in continuously spinning the microfibers via in situ photocrosslinking in extreme endovascular environments such as those involving a tortuous geometry and high absorbance. A double‐crosslinked alginate‐based hydrogel with tantalum nanopowder (DAT) that exploits the synergistic effect of covalent crosslinking by visible‐light irradiation and ionic crosslinking using Ca2+, which is present in the blood, is developed in this study. Furthermore, an effective strategy to design and produce an optical‐fiber‐integrated microfluidic device (OFI‐MD) that can continuously spin hydrogel microfibers via in situ photocrosslinking in extreme endovascular environments is proposed. As an embolic material, DAT exhibits promising characteristics such as radiopacity, nondissociation, nonswelling, and constant mechanical strength in blood, in addition to excellent cyto‐ and hemo‐compatibilities. Using OFI‐MD to spin DAT microfibers continuously can help fill aneurysms safely, uniformly, and completely within the endovascular simulator without generating microscopic fragments, which demonstrates its potential as an effective embolization strategy.

Photosensitive Hydrogel-Based Embolic Agent Treatment of Wide-Necked Aneurysms: Preliminary Animal Results

“…This makes photopolymerization a promising embolization strategy for aneurysms. Recently, Lim et al utilized photo-crosslinking at the tip of the catheter to spin hydrogel micro-fibers which were then ‘layered’ into a simple 3D model of cerebral aneurysms [ 38 ]. However, one specific advantage of a liquid embolization agent is the ability to completely ‘fill’ an aneurysm before solidification, and this may be lost with the aforementioned technique.…”

“…Similarly, Poupart et al injected hydrogel under balloon assistance with photopolymerization in in vitro silicone aneurysm models [ 30 , 39 ]. Both groups utilized an optical fiber placed within the wall of the injection microcatheter to transmit light from the laser source to the tip of the catheter [ 30 , 38 ].…”

Material‐Assisted Strategies for Osteochondral Defect Repair

“…Nonetheless, the recent report in the cardiovascular field of the use of a microfluidic device with an integrated optical fiber for in situ photocrosslinking is opening new perspectives for arthroscopically-crosslinkable materials. [193] A major limitation of using injectable scaffolds for OC repair is the difficulty to reproduce gradients and complex structures in situ. With this in mind, a few research groups recently investigated the feasibility of delivering bilayer implants by sequential injections of two solutions, corresponding to the two main layers of an OC tissue.…”

Wound Microenvironment-Responsive Protein Hydrogel Drug-Loaded System with Accelerating Healing and Antibacterial Property

“…Red blood cells (RBCs) are one of the most important members of an organism, responsible for oxygen exchange. 46 During the healing process, hydrogels will inevitably contact the blood cells, so excellent compatibility with RBCs becomes the prerequisite for the hydrogel system. 47 Thus, an acute hemolysis experiment was carried out to explore the RBC compatibility of hydrogels.…”