AG2

AG2 is a glucose uptake tracer and two-photon fluorescent probe. It is absorbed by cells through a glucose-specific transport system rather than passive diffusion and preferentially accumulates in cancer cells and colon cancer tissue compared to normal cells and tissues. Primarily localized in mitochondria, AG2 also exhibits minor distribution in the cytoplasm and cell membrane. It is useful for colon cancer research.

AG2 is a polarity-sensitive, pH-insensitive two-photon tracer with a remarkable Φδ value of 88 GM at a 780 nm wavelength in PBS buffer. At concentrations of 6-100 μM for 30 minutes, AG2 shows very low cytotoxicity in A549 cells, with 50 μM as the optimal concentration for cell uptake experiments since higher concentrations induce cell death. At 50 μM for 10 minutes, AG2 primarily localizes to the mitochondria and cytoplasm/membrane region in A549 cells, with selective detection in the cytoplasm via a 520-620 nm emission window. AG2 (50 μM; 10 min) is selectively absorbed by A549 and HeLa cancer cells over non-cancerous HEK293 and NIH/3T3 cells; its uptake in A549 cells is mediated by a glucose-specific transport system, as shown by competitive inhibition experiments with d-glucose rather than l-glucose. The uptake by A549 cells can be inhibited by paclitaxel and combretastatin in a time- and dose-dependent manner, suggesting AG2's utility in TPM for anticancer drug screening. Additionally, AG2 at 50 μM for up to 4000 seconds (or 4 hours) is more readily absorbed by human colon cancer tissues compared to normal tissues, and paclitaxel pretreatment can inhibit this process, allowing for visualization of glucose metabolism beyond 3000 seconds at depths of 75-150 μm using TPM.