Magnetically Controlled Delivery of Injectable Magnetoactive Adhesive Hydrogel for Vascular Repair in the Challenging Blood Environment

Repairing abnormal vessels in the complex fluidic and biological environment of blood remains challenging. Current approaches, such as non-adhesive polymeric sealants or vessel coiling, have unsatisfactory outcomes. Here, we present an injectable magnetoactive adhesive hydrogel (iMAH) for vascular repair in the challenging blood environment. Designed with biocompatible functional components, including the superparamagnetic component, a bio-inspired tissue adhesive, and quick-crosslinking agents, the catheter-deployable iMAH can be magnetically guided to a targeted site, quickly crosslink within approximately 2 s, and strongly adhere to the vessel surface in dynamic conditions with circulating and pressurized blood. Moreover, magnetic actuation enables targeted gel deployment and can drive the iMAH into a narrow and confined space, squeezing out interfacial fluid to facilitate high-strength tissue adhesion, as systematically investigated in vitro. Magnetically controlled delivery of iMAH for vascular repair has been demonstrated in a large-animal beagle dog model; branching lumbar arteries from the abdominal aorta, mimicking the opening of a ruptured artery, were successfully embolized under magnetic guidance using a 5-axis magnetic vascular robot. With these demonstrated features, magnetically controlled delivery of injectable magnetoactive adhesive hydrogel provides a promising solution for vascular repair such as sealing ruptured vessels or embolizing abnormal arteries in the challenging blood environment.