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Abstract

Radioisotopic imaging based on small molecules like carbohydrate has been regarded as a promising candidate for in-vivo imaging for cancer diagnosis in recent years. In this study, we report that N-acetyl neuraminic acid (Neu5Ac), a type of sialic acid with 9-carbon amino sugar and low pKa value coordinates with the transition radioactive metal 99m Tc. The radiochemical yield of 99m Tc labeled Neu5Ac was observed to be greater than 90% and was confirmed by Instant Thin Layer Chromatography. Molecular docking studies showed greater affinity of 99m Tc labeled Neu5Ac towards the lectin receptor when compared to cold Neu5Ac. The radiolabeled complex ( 99m Tc-Neu5Ac) binds specifically to the HT-29 cells and was mildly cytotoxic at a concentration of 402 µM. Cellular internalization of 99m Tc-Neu5Ac was mainly in the cytosolic proteins and free membranes as compared to nuclear fraction and large organelles. In conclusion, Neu5Ac was successfully radiolabeled with 99m Tc, and in-vitro binding studies confirmed that our developed radionuclide probe binds selectively to the cancer cells. Further, efficacy of our developed complex may be useful for the in-vivo imaging of cancer.