An Investigation on the Effect of Contrast Agents in the Chitosan-Nanoclay Shear Thinning Hydrogel for Trans-Catheter Arterial Embolization

Shear thinning hydrogels are emerging as a potential candidate of embolic agents for minimally invasive transcatheter arterial embolization because of their advantages over the commonly used conventional solid and liquid embolic agents. The transformation from solid to liquid and vice versa on the application and removal of shear force enables the shear thinning hydrogels to successfully occlude vasculatures of any diameters and thus can be used for the treatment of diseased or injured vasculature, including vascular malformation and malignant or benign tumors. Imageability of the embolic gel is of paramount importance as for successful occlusion of vasculatures requires real-time monitoring of the deployment of the embolic agents. Here, we studied the effect of different contrast agents, including iohexol, Omnipaque^TM and tantalum microparticles, on the radiopacity on an established chitosan-nanoclay hydrogel system. The flow behavior and recoverability of the developed gels are not compromised by the addition of radiopaque contrast agents. The injection force of the gels through a clinically relevant catheter was measured to evaluate the practicality of hand injection. The gels exhibited exceptional contrast under x-ray imaging modality. In addition, the radiopaque gels demonstrated excellent hemocompatibility and cell biocompatibility, highlighting their potential for transcatheter arterial embolization.