Polymer microspheres in endovascular therapy: From fundamental research to clinical application

This review highlights the current state of research in the field of the use of microspheres based on natural and synthetic polymers for embolization of hepatocellular carcinoma vessels, embolization of arteries in patients with paragangliomas, uterine myoma, prostatic hyperplasia and hemorrhoids. Particular attention in the review is paid to clinical studies of various sizes of microspheres to determine the effectiveness and safety of embolization processes. Based on the analysis of works over the past five years in the field of chemoembolization and radioembolization, it can be concluded that the most promising polymer matrices for the development of microspheres are cross-linked natural polymers, such as gelatin and chitosan. It has been established that polyvinyl alcohol microspheres and liquid embolizing agents based on ethylene-vinyl alcohol copolymer are effective and safe for preoperative embolization of patients with paragangliomas of various localizations. It is shown that the most promising embolizing agents for the treatment of uterine myoma, prostate hyperplasia and internal hemorrhoids are microspheres of cross-linked trisacryl coated with gelatin and microspheres based on polymethyl methacrylate coated with polyphosphazene. Unlike previous reviews focusing on single applications, this work provides a unique cross-disciplinary analysis of polymer microsphere embolization across multiple clinical specialties, highlighting material-design-clinical outcome relationships. The review may be of interest to bioengineers, materials scientists, chemists, and physicians working in the field of biopolymer materials and interventional therapies.