Preparation and Preliminary Biological Evaluation of Novel 99mTc-Labelled Thymidine Analogs as Tumor Imaging Agents

Abstract

Two kinds of novel thymidine derivatives, N-thymidine-yl-N′-methyl-N′-{N′′-[2-sulfanyl-(ethylamino)acetyl]-2-aminoethylsulfanyl-1-hexanamide}-ethanediamine (TMHEA) and N-thymidine-yl-N′-methyl-N′-{N′′-[2-sulfanyl-(ethylamino)acetyl]-2-aminoethylsulfanyl-1-hexanamide}-hexanediamine (TMHHA) were prepared and successfully labeled with 99mTc in high labeling yields. The in vitro stability and in vivo biodistribution of 99mTc-TMHEA and 99mTc-TMHHA were investigated and compared. The biodistribution studies indicate that the radiotracer 99mTc-TMHEA displays selective tumor uptake, suggesting it is a potential tumor imaging agent.

PET Imaging of Bacterial Infections with Fluorine‐18‐Labeled Maltohexaose

“…Several factors have contributed to the lack of success of bacteria imaging agents, such as poor clearance as a result of nonspecific adsorption, low target-receptor expression on bacteria, or complicated radiochemical synthesis, which are challenging to perform in clinical radiochemistry labs. [10] Therefore, there is a great need for the development of new PET contrast agents that can image small numbers of bacteria with high specificity in vivo. [11] Herein, we present a new PET tracer, composed of 18 Flabeled maltohexaose (MH 18 F), that can image bacterial infections in vivo with unprecedented sensitivity and specificity (see Scheme 1).…”

PET Imaging of Bacterial Infections with Fluorine‐18‐Labeled Maltohexaose

“…[5] 18 FDG therefore cannot distinguish bacterial infections from other pathologies such as cancer and inflammation, and cannot diagnose bacterial infections at an early stage. [10] Therefore, there is a great need for the development of new PET contrast agents that can image small numbers of bacteria with high specificity in vivo. Several factors have contributed to the lack of success of bacteria imaging agents, such as poor clearance as a result of nonspecific adsorption, low target-receptor expression on bacteria, or complicated radiochemical synthesis, which are challenging to perform in clinical radiochemistry labs.…”

Novel 99mTc-labelled complexes with thymidine isocyanide: radiosynthesis and evaluation as potential tumor imaging tracers

“…9 In the following ten years, many 99m Tc-labelled thymidine derivatives have been prepared and evaluated. [10][11][12][13][14][15][16][17][18][19][20] Unfortunately, none of them had the ideal properties to be used in clinical imaging. In a previous work of our group, a series of 99m TcIJCO) 3 -labelled thymidine macrocyclic analogs were synthesized and their biodistributions were systematically evaluated.…”