Tc 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 Tc. The radiochemical yield of 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 Tc labeled Neu5Ac towards the lectin receptor when compared to cold Neu5Ac. The radiolabeled complex (Tc-Neu5Ac) binds specifically to the HT-29 cells and was mildly cytotoxic at a concentration of 402 μM. Cellular internalization of 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 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. INTRODUCTION: Technetium(Tc) is the most prevalent diagnostic radionuclide in nuclear medicine due to its easy availability from commercial generator columns, ideal nuclear properties, and suitable decay characteristics. It emits γ-rays with an energy of 140 keV, which is close to optimal for imaging with commercial gamma cameras. The six-hour half-life is sufficiently long for pharmaceutical preparation and in-vivo accumulation in the target 1, .