Size-tunable and biodegradable thrombin-functionalized carboxymethyl chitin microspheres for endovascular embolization

As a minimally invasive method, endovascular embolization has been an effective strategy for controlling bleeding and tumor treatment. Herein, carboxymethyl chitin embolic microspheres were prepared with the aqueous two-phase carboxymethyl chitin/polyethylene glycol system without using any crosslinking agents and thrombin-functionalized embolic microsphere named as [email protected] was made after covalent introduction of thrombin. The size of the microspheres can be adjusted from 5 to 500 μm. The data of in vitro and in vivo tests indicated that these microspheres possessed good degradability and biocompatibility. Meanwhile, [email protected] can significantly promote blood clotting and enhance the strength of the blood clots . More importantly, [email protected] displayed better embolization effect than that of the commercial available Gelfoam Alicon® and polyvinyl alcohol-based embolic microspheres CalliSpheres® in rat femoral vein and rabbit ear artery embolization models. Therefore the size-tunable and biodegradable thrombin-functionalized carboxymethyl chitin microspheres [email protected] possess great potential for effective hemostasis and endovascular embolization.