Biomaterials for injectable therapeutic implants

Injectable biomaterials that have the ability to form semi-solid implants in situ are of keen interest for therapeutic applications. The materials may be used to fill in pathological vascular spaces or be designed to possess functional properties such as being radiopaque for an improved visibility during image-guided minimally invasive interventions, or induce a localized biological activity. Among the variety of solidification principles that may be used to produce implants in situ, the precipitation of water-insoluble polymers driven by solubility changes shows some particular features that may be valuable for specific therapeutic applications. This paper reviews some of the applications of these implant-forming biomaterials in interventional radiology, urology, and oncology.