The effect of I-131 labeled chitosan micro-hydrogels for transarterial radioembolization in a rodent hepatoma model

Objectives Transarterial embolization has been used as one of therapeutic modalties against liver cancers. It keeps blood supply of tumor interrupted by embolic particles infused into hepatic arteries via a catheter. In this study, we prepared chitosan-based micro-hydrogels for hepatic arterial radio-embolization to treat a hepatoma.

Methods Chitosan was conjugated with sulfo-succinimidyl-3-(4-hydroxypheynyl) propionate (SHPP) as a chelator for I-131 labeling and then the chitosan-SHPP conjugate was formulated into a spherical micro-hydrogels using an electro-spinning method. The micro-hydrogels were separated by centrifugation and suspended in phosphate buffer. To evaluate therapeutic effects the micro-hydrogels were infused in a rat of the hepatic artery using a catheter. Finally, gamma images were acquired to identify the retention of the micro-hydrogels in the infused hepatic lobes and the other organs.

Results I-131 labeling efficiency of chitosan-SHPP was 60±5% and the radiolabeling stability was more than 90% for one week. The size of chitosan micro-hydrogels was 150±10 µm. The infused I-131 labeled chitosan micro-hydrogels were almost localized to the left hepatic lobe having an orthotopic hepatoma. In particular, there were no any significant leakage of I-131 to the other organs, especially to lungs and thyroid glands.

Conclusions The characteristics of chitosan micro-hydrogels, such as I-131 labeling efficiency, radiolabeling stability, particle size, and retention in a hepatic tissue, indicate that the micro-hydrogels are compatible to effective transarterial radioembolization (TARE) for hepatoma therapy. I-131 labeled chitosan micro-hydrogels infused through the hepatic artery significantly decreased the tumor volume in a rat hepatoma model. As the results, I-131 labeled chitosan micro-hydrogels show the good possibility as a new material for effective hepatoma therapy.