Vascular embolization of radiopaque hydrogel microfiber using ultra-minimally invasive technique for stage-adjustable renal failure model

[Display omitted] •Radiopaque hydrogel microfibers made of barium alginate containing zirconia particles were fabricated by the double coaxial laminar flow microfluidic device.•Zirconia particles improved the visibility of the microfiber in vivo by using X-ray angiography.•The microfiber was delivered accurately and embolized the target blood vessel.•The creation of the rat’s renal failure model with controlled symptoms was demonstrated by delivering the radiopaque microfibers. Animal pathology models play an important role in elucidating pathology, evaluating drug efficacy, and studying therapeutic. This paper presents the creation of rats’ renal failure model by embolizing the renal artery using radiopaque hydrogel microfibers. By using a dual coaxial laminar flow microfluidic device, barium alginate gel microfibers containing zirconia particles were fabricated. Since the zirconia particles are radiopaque, the microfiber can be delivered and embolized while confirming the position of the microfiber in real-time under X-ray imaging. The delivery of microfibers through a catheter into the renal artery of rats to create a renal failure model was tested. The radiopaque microfibers were visualized by X-ray imaging when delivered by a catheter. Furthermore, the microfibers remained stable for 2 weeks after delivery. In addition, by adjusting the number of microfibers, two different rat models with severe and mild renal failure conditions were created. The proposed delivery of radiopaque hydrogel microfibers to create an embolization model is expected to be an effective approach to control the degree of symptoms and elucidate the pathology.