Initial evaluation of 99mTc ‐labeled anti‐carcinoembryonic antigen single‐chain fragment variable for micro‐single‐photon emission computed tomography imaging in mice with colorectal cancer

In this study, we report the production and radiolabeling of a novel anti-CEA single-chain fragment variable (scFv-96NRT, concentration for 50% of maximal effect 46  ng/ml), and evaluation of [99mTc]Tc-scFv-96NRT in non-invasive detection of CEA expression. [99mTc]Tc-scFv-96NRT was synthesized by one step reduction in labeling yield of>95% with radiochemical purity of>98% and molar activity of 10 –11 GBq/μmol. [99mTc]Tc-scFv-96NRT showed high stability in 0.01 M phosphate-buffered saline (PBS) and 5% human serum albumin (HSA). It exhibited elevated uptake in CEA over-expressing cells. Biodistribution studies in BALB/c mice revealed that the probe was cleared from blood rapidly, and the highest retention was observed in the kidneys. The micro-single-photon emission computed tomography (micro-SPECT) imaging of [99mTc]Tc-scFv-96NRT showed a specific accumulation pattern, as blocking experiment with excess scFv-96NRT suppressed the tumor uptake. These preliminary results suggest that [99mTc]Tc-scFv-96NRT is a potential non-invasive molecular probe for imaging tumors with CEA over-expression.
Source: Journal of Labelled Compounds and Radiopharmaceuticals - Category: Biochemistry Authors: Tags: RESEARCH ARTICLE Source Type: research