X-ray visible and doxorubicin-loaded beads based on inherently radiopaque poly(lactic acid)-polyurethane for chemoembolization therapy

The aim of current study was to develop drug-loaded polymeric beads with intrinsic X-ray visibility as embolic agents, targeting for noninvasive intraoperative location and postoperative examination during chemoembolization therapy. To endow polymer with inherent radiopacity, 4,4'-isopropylidinedi-(2,6-diiodophenol) (IBPA) was firstly synthesized and employed as a contrast agent, and then a set of radiopaque iodinated poly(lactic acid)-polyurethanes (I-PLAUs) via chain extender method were synthesized and characterized. These I-PLAU copolymers possessed sufficient radiopacity, in vitro non-cytotoxicity with human adipose-derived stem cells, and in vivo biocompatibility and degradability in rabbit model via intramuscular implantation. Doxorubicin (DOX), as a chemotherapeutic agent, was further incorporated into I-PLAU beads via a double emulsification (W/O/W) method. For drug release, two ratios of DOX-loaded I-PLAU beads exhibited calibrated size (200-550 mu m), porous internal structure, good X-ray visibility, evenly drug loading as well as tunable drug release. A preliminary test on in vitro tumor cell toxicity demonstrated that the DOX-loaded I-PLAU beads performed efficient anti-tumor effect. This study highlights novel X-ray visible drug-loaded I-PLAU beads used as promising embolic agents for non-invasive in situ X-ray tracking and efficient chemotherapy, which could bring opportunities to the next generation of multifunctional embolic agents. (C) 2017 Elsevier B.V. All rights reserved.