Developing Resorbable and Drug-Eluting Embolization Microspheres

ABK Biomedical is a medical device company specializing in materials that can be injected into blood vesselsin order to block blood flow to a target tissue (a process called embolization). ABK's embolization materialsare intrinsically radiopaque, meaning that physicians can monitor their placement using conventional imagingtechniques, but they do not break down in the body. The company would like to expand its product line toinclude radiopaque embolization materials that will eventually break down (resorb) and be assimilated by thesurrounding tissues while slowly releasing drug into this localized region.Phosphate-based glasses developed by the Filiaggi group at Dalhousie University have the advantage of beingresorbable and can, under highly controlled low-temperature processing conditions, be loaded with drugs thatcan be released as the glass resorbs. Recent studies have further demonstrated that these processing conditionscan be adapted to produce small glass spheres or beads.In this project we will develop radiopaque embolic microspheres that resorb within 1 to 3 weeks and can beloaded with - and subsequently release - the most commonly used embolization drugs. To achieve these goals,we will systematically modify the composition of the phosphate glass and evaluate the degradation,radiopacity, and drug loading efficiency and release in order to determine the processing conditions (andresulting formulations) best suited to meet the medical device design requirements. With assistance from ourindustrial partner we will also assess the ease with which these beads can be delivered in a catheter - theprimary mode of delivery for embolization procedures, and employ design methods to enhance microsphereproduction efficiency in the 100-300 µm size range, as is desired for embolic applications.With funding from this NSERC Engage grant, a new and ongoing industry collaboration will be forged thatwill yield novel resorbable, radiopaque and drug-eluting embolization materials of considerable commercialinterest.