Tunable Biodegradable Methacrylate Gelatin Microspheres Enable Renal Artery Embolization

Area of Science:

• Biomaterials Science
• Interventional Radiology
• Nephrology

Background:

• Renal artery hemorrhage (RAH) is a critical condition requiring effective treatment.
• Super-selective renal artery embolization (SRAE) is a key intervention for RAH.
• Existing embolic agents have limitations including failure, tissue damage, and recurrence.

Purpose of the Study:

• To develop and evaluate biodegradable gelatin methacryloyl (GelMA) microspheres as a novel embolic agent for SRAE.
• To assess the tunable degradation, biocompatibility, and efficacy of GelMA microspheres in a preclinical model.

Main Methods:

• Synthesized GelMA microspheres with varying degrees of substitution (DS0.25, DS0.75) using microfluidics and photopolymerization.
• Evaluated in vitro degradation, biocompatibility (cell viability, hemolysis), and in vivo efficacy in a rabbit RAH model.
• Utilized digital subtraction angiography (DSA) and CT for embolization guidance and follow-up, with histopathological analysis.

Main Results:

• Uniform GelMA microspheres (175 ± 4 μm) were fabricated with tunable degradation rates (DS0.25 degraded in 60 days, DS0.75 partially degraded in 100 days).
• GelMA microspheres demonstrated excellent biocompatibility with >90% cell viability and <3% hemolysis.
• In vivo, GelMA-DS0.25 achieved effective embolization, initiated degradation around 16 days, and showed no irreversible renal injury.

Conclusions:

• Biodegradable GelMA microspheres offer tunable degradation and good biocompatibility for SRAE.
• These microspheres represent a promising alternative to current embolic agents for RAH treatment.
• Further research into GelMA microspheres could advance interventional treatment for renal bleeding.