Differentiated imaging of Hashimoto's thyroiditis against Thyroid carcinoma by endogenous peroxynitrite activated near-infrared fluorescent probe

Abstract

Hashimoto's thyroiditis is one of the most common autoimmune diseases. Due to the similarity of the traits, traditional examination methods may misdiagnose it as thyroid cancer in some cases. Accurate diagnosis of Hashimoto's thyroiditis can avoid organ resection by misdiagnosis of thyroid cancer, preserve organ function for patients and reduce surgical trauma. Here, we designed and synthesized a near-infrared fluorescent probe named HNTC-HT for differentiated imaging of Hashimoto's thyroiditis against thyroid carcinoma. Reactive oxygen species (ROS), such as peroxynitrite (ONOO⁻), highly accumulated in Hashimoto's thyroiditis. While the content of ROS in thyroid cancer cells was significantly lower than that in Hashimoto's thyroiditis cells. ONOO⁻ removes the trifluoromethanesulfonic acid group by affinity substitution reaction. And then HNTC-HT restores to fluorophore HNTC-OH which produces near-infrared fluorescence due to intramolecular charge transfer (ICT). We successfully perform differentiated imaging of Hashimoto's thyroiditis against thyroid carcinoma with HNTC-HT by the specific detection of intracellular ONOO⁻. The fluorescence brightness of thyroiditis cells is much higher than thyroid cancer cells, which proves that the probe HNTC-HT can be used to effectively differentiate Hashimoto's thyroiditis against thyroid cancer cells. Satisfactory results were also obtained in subsequent mouse experiments. In this work, the fluorescence probe HNTC-HT activated by ROS has been more appropriately applied, so as to address the limit in the misdiagnosis of Hashimoto's thyroiditis as thyroid cancer, thus expanding potential applications of near-infrared fluorescent probe in the diagnosis of thyroid disease.