Initial evaluation of 99mTc ‐labeled anti‐CEA scFv for micro‐SPECT 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. Bio-distribution 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