Injectable hyaluronic acid microgels carrying radioactive iodine-131 offer a precise, minimally invasive method to deliver localized radiation therapy to keloid scars, according to a preclinical study published by researchers at Pusan National University. The strategy aims to overcome the targeting limitations of conventional external-beam radiation when treating small, irregular skin lesions.
The Keloid Treatment Challenge and Conventional Limitations
Keloids form as abnormal, fibroproliferative scars when overactive fibroblasts produce excessive collagen after skin injuries. These growths frequently extend beyond original wound margins, causing persistent pain, tenderness, and itching. Standard interventions like surgery, corticosteroid injections, and lasers often require prolonged care cycles and carry high recurrence rates. While radiotherapy can suppress keloid growth, conventional external-beam machines struggle to precisely target small, irregular lesions while protecting surrounding healthy tissue, according to background data in the study.
Microfluidic Hyaluronic Acid Microgels and Fast Radiolabeling
To solve precision problems, a research team led by Prof. Seung Yun Yang—who also serves as CEO of SNVIA Co., Ltd.—developed an off-the-shelf microbrachytherapy system. Investigators fabricated uniform, biodegradable hyaluronic acid (HA) microgels using microfluidic technology and freeze-drying. This created a porous structure capable of absorbing radioactive solutions rapidly. According to Prof. Yang, the freeze-dried microgels achieve high labeling efficiency greater than 90 percent with radioactive iodine-131 (¹³¹I) in under 10 minutes through absorption-mediated rapid radiolabeling.
Pro Tip: On-site radiolabeling systems can streamline hospital workflows by reducing radioactive waste and logistical demands, allowing clinicians to tailor doses precisely to individual lesion geometries.
Preclinical Efficacy and Safety Outcomes in Animal Models
Researchers evaluated the labeled microgels using patient-derived keloid fibroblasts and mouse xenograft models. In laboratory tests, ¹³¹I-HA microgels at doses of 10 MBq or higher induced more than 80 percent keloid fibroblast death within 48 hours, operating primarily through apoptosis. When researchers administered intralesional injections in mice, the microgels stayed localized inside the keloid tissue for up to 14 days and reduced keloid size by about 70 percent after two weeks. The study noted no off-target biodistribution, damage to surrounding healthy tissue, or significant abnormalities in major organs, blood parameters, or thyroid function.
The research team plans to adapt the platform for other localized tumors, though broader applications require further investigation. The paper was made available online on August 10, 2026, and is scheduled for publication in Volume 398 of the Journal of Controlled Release on October 10, 2026. Longer-term studies remain necessary to evaluate clinical safety, dose distribution, immune responses, and recurrence rates before human deployment.
Did You Know?
Keloids are classified as abnormal, fibroproliferative scars, meaning they form when overactive fibroblasts produce excessive collagen after skin injuries.
Frequently Asked Questions
What are keloids?
Keloids are abnormal, raised scars that develop when the body produces excess collagen during the healing process, often extending beyond the borders of the original injury.
How do radioactive hyaluronic acid microgels work?
According to the Pusan National University study, biodegradable hyaluronic acid microgels absorb radioactive iodine-131 on-site and act as localized radiation reservoirs when injected directly into the keloid tissue.
When will this microbrachytherapy treatment be available for patients?
The technology is currently in the preclinical research stage following animal studies and in vitro testing. Longer-term clinical trials are required before doctors can offer the treatment to patients.