A Radiopaque and Thermoresponsive Nanogel-Based Pickering Emulsion for Permanent Arterial Embolization

Area of Science:

• Biomaterials Science
• Interventional Radiology
• Nanotechnology

Background:

• Conventional embolic agents for transcatheter arterial embolization (TAE) lack intrinsic radiopacity, requiring a two-step process with lipiodol.
• There is a clinical need for advanced embolic materials offering integrated imaging and improved biocompatibility for better patient outcomes.

Purpose of the Study:

• To develop and evaluate a novel, intrinsically radiopaque, thermosensitive liquid embolic material for TAE.
• To assess the feasibility, safety, and efficacy of this new material in preclinical models.

Main Methods:

• Synthesis of poly-(N-isopropylacrylamide)-co-acrylic acid nanogels (PNAs).
• Formulation of a thermosensitive lipiodol-based gel emulsion (TLGE) by mixing PNAs with lipiodol.
• Evaluation of TLGE injectability, X-ray contrast, and biocompatibility in ex vivo and in vivo models (decellularized liver, rabbit renal artery).
• Intraoperative monitoring using digital subtraction angiography (DSA).

Main Results:

• The developed TLGE demonstrated excellent temperature sensitivity, injectability, and intrinsic X-ray contrast.
• A single-injection embolization technique was successfully established, simplifying the procedure.
• Preclinical studies in rabbits showed no vessel recanalization or nontarget organ damage after 42 days.

Conclusions:

• The novel thermosensitive liquid embolic material (TLGE) offers significant advantages over conventional agents for TAE.
• This temperature-sensitive nanogel-based emulsion presents a promising, safer, and more efficient option for clinical transcatheter arterial embolization procedures.