Construction of an Injectable Composite Double-Network Hydrogel as a Liquid Embolic Agent

Area of Science:

• Biomaterials Science
• Interventional Radiology
• Drug Delivery Systems

Background:

• Conventional embolic agents often fail due to rigidity and instability, leading to recanalization.
• Intelligent hydrogels with tunable properties present a promising alternative for improved therapeutic efficacy.

Purpose of the Study:

• To develop an injectable composite double-network (CDN) hydrogel as a liquid embolic agent.
• To enhance the hydrogel's injectability, mechanical properties, and therapeutic agent loading capacity.

Main Methods:

• Synthesized an injectable CDN hydrogel using poly(vinyl alcohol) (PVA) and carboxymethyl chitosan (CMC) with dynamic covalent cross-linking.
• Incorporated layered double hydroxide (LDH) nanosheets to reduce yield stress and enable therapeutic agent loading (indocyanine green, doxorubicin).
• Demonstrated in situ strengthening via secondary cross-linking with phosphate ions for improved mechanical properties and degradation duration.

Main Results:

• The CDN hydrogel exhibited shear-thinning behavior, allowing injection through thin catheters.
• Incorporation of LDH facilitated loading of indocyanine green for photothermal therapy and doxorubicin for chemotherapy.
• In vivo studies in rabbits showed successful renal embolization and inhibition of subcutaneous tumor growth.

Conclusions:

• The developed CDN hydrogel represents a novel generation of interventional embolization agents with reduced risks.
• This hydrogel system offers a versatile platform for combining embolization with targeted therapies like photothermal therapy and chemotherapy.