Off-the-shelf microbrachytherapy using on-site fast radiolabeling for keloid treatment

Area of Science:

• Biomedical Engineering
• Radiotherapy
• Dermatology

Background:

• Keloids are challenging fibroproliferative tumors resulting from abnormal skin healing.
• Current treatments for keloids are often prolonged and have limited efficacy.
• Radiotherapy can reduce keloid recurrence, but external beams lack precision for small lesions.

Purpose of the Study:

• To develop an off-the-shelf microbrachytherapy using on-site radiolabeled microgels for keloid treatment.
• To create injectable, biodegradable hyaluronic acid (HA) microgels labeled with iodine-131 (¹³¹I).

Main Methods:

• Uniform freeze-dried HA microgels with functional groups were prepared.
• Rapid absorption-mediated radiolabeling of microgels with ¹³¹I was achieved (>90% efficiency in 10 min).
• The efficacy and safety of intralesional injection of ¹³¹I-labeled HA microgels were evaluated in a keloid xenograft model.

Main Results:

• The developed ¹³¹I-labeled HA microgels demonstrated high radiolabeling efficiency and stability (>98%).
• Intralesional injection of the microgels significantly reduced keloid size by 70% within two weeks in a xenograft model.
• No off-target biodistribution or damage to surrounding healthy tissues was observed.

Conclusions:

• On-site rapid radiolabeling of microgels offers a universal platform for developing localized radiotherapies.
• This approach provides a user-demanded, programmed, off-the-shelf solution for keloid treatment.
• Injectable radioactive microgels represent a promising advancement in managing refractory keloid conditions.