Abstract P784: A Novel Rat Model of Embolic Cerebral Ischemia Using a Cell-Implantable Radiopaque Hydrogel Micro Fiber

Abstract

Introduction: The failure of neuroprotective treatment-related clinical trials may be partially caused by unestablished animal models. We aimed to develop a novel focal stroke model using a cell-implantable radiopaque hydrogel micro fiber. The micro fiber is made of barium alginate hydrogel containing zirconia, and fabricated in a dual coaxial laminar flow microfluidic device. Methods: Using male Sprague Dawley rats (n=10), a catheter (ID 0.42mm, OD 0.55mm) was navigated from the caudal ventral artery to the left internal carotid artery using digital subtraction angiography. A radiopaque hydrogel micro fiber (0.4 mm in diameter, 1 mm in length) was advanced in the catheter by slow injection of heparinized physiological saline to establish local occlusion. 9.4-T MRI and 2% 2,3,5-triphenyl tetrazolium chloride staining were performed 24 hours after the creation of the stroke model. Results: The anterior cerebral artery-middle cerebral artery bifurcation was selectively embolized at all rats. The median operating time was 8.5 min (interquartile range; 6.25-12 min). The median infarct volume (mm 3 ) was 262 (interquartile range; 260-274) 24 hours after occlusion. Conclusions: We present a novel rat model for focal infarct only in the middle cerebral artery territory using a radiopaque hydrogel micro fiber. Furthermore, this model can be used for regeneration research of cerebral infarction because the hydrogel micro fiber can encapsulate stem cell.Figure Legends A: Puncture of the caudal ventral artery in a rat. B: Cerebral angiography of a rat. C: Occlusion of the anterior cerebral artery-middle cerebral artery bifurcation by a radiopaque hydrogel fiber (arrowhead). D: MR angiography detected selective occlusion of left middle cerebral artery. E: T2-weighted image showed infarct only in the middle cerebral artery after 24 hours occlusion. A radiopaque fiber did not affect the 9.4-T MRI. F: Radiopaque hydrogel fiber encapsulated HeLa cells.