The prevalence of intracranial aneurysms is about 1.6% in the general population; with a rupture rate of approximately 1% per year. This translates into approximately 30,000 cases per year in the U.S. It is estimated that an equal number of unruptured aneurysms, usually discovered incidentally, are also treated. Endovascular therapy has recently evolved as a minimally invasive treatment for cerebral aneurysms and is slowly becoming almost the mainstay of care; it generally involves the deployment of metallic microcoils into the aneurysm dome through a catheter. Theoretically, aneurysm embolization is achieved via coils that induce arterial stasis within the dome leading to clotting and later fibrosis with ultimately obliteration. The major limitation of microcoils was underscored by autopsy reports compiled indicating incomplete obliteration of most aneurysms. Attempts to enhance the performance of metallic coils have hitherto shown limited success. Liquid embolic agents have been developed but their performance characteristics have to be greatly improved before they can be acceptable universally by clinicians. The goal of this project is to develop a biocompatible and biodegradable in situ gelable carbohydrate hydrogel without the limitations of the liquid embolic agents currently available for aneurysm filling. The hydrogel properties and composition will be further optimized and the non-cytotoxicity will be validated. Sufficient clinical grade materials will be produced for future in vivo and clinical studies. The project will be concluded after performing in vivo efficacy evaluations in canine aneurysm models. This Phase I SBIR project will set the stage for developing a liquid embolic agent which is easier to use and the therapeutic outcome of treating an aneurysm can be improved by shortening the time to complete occlusion. [unreadable] [unreadable] [unreadable]