99mTc LABELED N-ACETYL NEURAMINIC ACID AS A NEW RADIONUCLIDE PROBE FOR TARGETING CANCER: IN-SILICO AND IN-VITRO STUDY

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 ^99mTc. The radiochemical yield of ^99mTc labeled Neu5Ac was observed to be greater than 90% and was confirmed by Instant Thin Layer Chromatography. Molecular docking studies showed greater affinity of ^99mTc labeled Neu5Ac towards the lectin receptor when compared to cold Neu5Ac. The radiolabeled complex (^99mTc-Neu5Ac) binds specifically to the HT-29 cells and was mildly cytotoxic at a concentration of 402 µM. Cellular internalization of ^99mTc-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 ^99mTc, 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.