PET probe with Aggregation Induced Emission characteristics for the specific turn-on of aromatase

Aromatase is an attractive target for the diagnosis and treatment of breast cancer. To combine the anti-photobleaching properties of Aggregation Induced Emission (AIE) with the high sensitivity and whole-body imaging characteristics of positron emission tomography (PET), we designed a bifunctional complexing agent with AIE characteristics by modifying the structure of tetraphenylethene, which is linked with triazole derivatives capable of complexing with ^natGa³⁺/⁶⁸Ga³⁺ to obtain [^natGa/⁶⁸Ga] 2 for targeting the aromatase. [^natGa] 2 has typical AIE characteristics, which can form uniform nanomicelles above the critical micelle concentration, and illuminate estrogen receptor (+) MCF-7 cells. [^natGa] 2 itself is almost nonemissive in PBS buffer solution, but it turns on its fluorescence upon interaction with human aromatase, with a detection limit of 0.15 μg/mL [⁶⁸Ga] 2 is easy to prepare and has high stability. Compared to the estrogen receptor that is negatively expressed by MDA-MB-231  cells, MCF-7  cells positively expressing estrogen have a higher uptake of [^natGa] 2. The distribution of aromatase in a tumor can be co-localized by using [⁶⁸Ga] 2. These results can be used to effectively assess estrogen receptor status and aromatase levels at the cellular level. We anticipate that this research could provide a new strategy for the fabrication of PET probes with AIE characteristics, providing useful probes for PET- FL (Fluorescence imaging) bimodal imaging.