Abstract
Background: New approaches based on the receptor-targeted molecular interaction have been recently developed with the aim to investigate specific probes for sentinel lymph nodes. In particular, the mannose receptors expressed by lymph node macrophages became an attractive target and different multifunctional mannose derivate ligands for the labeling with 99mTc have been developed. In this study, we report the synthesis of a specific class of dextran-based, macromolecular, multifunctional ligands specially designed for labeling with the highly stable [99mTc≡N]2+ core. Methods: The ligands have been obtained by appending to a macromolecular dextran scaffold pendant arms bearing a chelating moiety for the metallic group and a mannosyl residue for allowing the interaction of the resulting macromolecular 99mTc conjugate with specific receptors on the external membrane of macrophages. Two different chelating systems have been selected, S-methyl dithiocarbazate [H2N‒NH‒C(=S)SCH3=HDTCZ] and a sequence of two cysteine residues, that in combination with a monophosphine coligand, are able to bind the [99mTc≡N]2+ core. Conclusions: High-specific-activity labeling has been obtained by simple mixing and heating of the [99mTc≡N]2+ group with the new mannose-dextran derivatives.
Highlights
The sentinel lymph node (SLN) is defined as the first lymph node that receives lymphatic drainage as well as metastatic cells from the primary tumor sites
Sentinel lymph node detection (SLND) is a radionuclide-based technique for imaging regional lymph node drainage systems, performed by injecting small radiolabeled particles (20 to 500 nm). This technique has become the standard of care in breast cancer [1,2] and melanoma [3,4], and is increasingly being applied to other solid cancers with high metastatic potential in lymph nodes, such as oral and oropharyngeal squamous cell carcinoma [5]
The most frequently used radiopharmaceuticals for SLND are 99mTc-labelled colloidal particles. They are characterized by nonideal properties [6,7,8]; in particular, their uptake mechanism is driven by passive diffusion and show slow clearance rate from the injection site or low residence time in the SLN [9,10,11,12]
Summary
The sentinel lymph node (SLN) is defined as the first lymph node that receives lymphatic drainage as well as metastatic cells from the primary tumor sites. Sentinel lymph node detection (SLND) is a radionuclide-based technique for imaging regional lymph node drainage systems, performed by injecting small radiolabeled particles (20 to 500 nm). The most frequently used radiopharmaceuticals for SLND are 99mTc-labelled colloidal particles They are characterized by nonideal properties [6,7,8]; in particular, their uptake mechanism is driven by passive diffusion and show slow clearance rate from the injection site or low residence time in the SLN [9,10,11,12]. Conclusions: High-specific-activity labeling has been obtained by simple mixing and heating of the [99mTc≡N]2+ group with the new mannose-dextran derivatives
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
