Injectable PEG/polyester thermogel: A new liquid embolization agent for temporary vascular interventional therapy.

Area of Science:

• Biomaterials Science
• Medical Devices
• Polymer Chemistry

Background:

• Injectable liquid embolic agents are crucial for vascular interventions.
• Current agents like Onyx™ have limitations in injectability and thermoreversible properties.
• Poly(ethylene glycol)/polyester thermogels offer potential advantages over existing embolic agents.

Purpose of the Study:

• To evaluate the feasibility of an injectable methoxy PEG-poly(d,l-lactide) (mPEG-PLA) copolymer thermogel for temporary vascular interventional therapy.
• To assess the safety and efficacy of mPEG-PLA thermogel in a large animal model.
• To investigate the radiopacity and injectability of the mPEG-PLA thermogel with an X-ray contrast agent.

Main Methods:

• An injectable mPEG-PLA thermogel was synthesized and characterized.
• The thermogel's sol-gel transition properties and radiopacity with a contrast agent were evaluated.
• In vivo feasibility was assessed in a swine model, comparing preparation time, injectability, and embolization efficacy with traditional agents.
• Arterial recanalization was monitored post-embolization.

Main Results:

• The mPEG-PLA thermogel exhibited reversible sol-gel transitions and good injectability.
• Addition of an X-ray contrast agent conferred radiopacity without significantly altering gelation.
• Temporary arterial embolization was achieved in swine.
• Arteries recanalized within 1 hour post-operation.
• mPEG-PLA thermogel required less preparation time and was more convenient to inject than traditional agents.

Conclusions:

• The mPEG-PLA thermogel demonstrates potential as a temporary pre-surgical embolic agent for tumor resection.
• Further research is needed to enhance the gel's mechanical strength for improved embolization efficacy.
• The material shows promise for vascular interventional therapy due to its favorable properties.