One hundred micrograms of monoclonal antibody (MoAb) CHA255 with a binding constant Kb of 4 X 10(9) was complexed with indium-111 labelled BLEDTA II, BLEDTA IV, benzyl EDTA, and an EDTA conjugate of Fab. The 24-h tumour and organ distribution of BALB/c mice bearing KHJJ tumours was studied for each compound alone, the antibody complex, and 3 h following a chelate chase of the antibody complex. Whole body biological half-life was measured for 7 days with and without a chelate chase for each antibody complex. The 24-h whole body counts dropped 20 to 60% and blood concentration fell over 89% within 3 h of administering the chelate chase. Theoretical equivalent human organ doses were calculated from the 24-h organ concentrations, effective half-life, and MIRD 11 S values (absorbed dose per cumulated activity). Liver and spleen were the target organs, with the dose ranging from 0.50 to 3.91 rads mCi-1. The reduction in organ radiation dose varied up to 95% following the chelate chase. Rapid selective renal clearance of chelate labelled radiopharmaceuticals by competitive inhibition (chelate chase) of their reversible binding to monoclonal antibodies enhances tumour imaging and improves the radiation dosimetry.
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Mol Ther
January 2025
Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, Harvard University, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Department of Materials Science of Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Electronic address:
mRNA delivered using lipid nanoparticles (LNPs) has become an important subunit vaccine modality, but mechanisms of action for mRNA vaccines remain incompletely understood. Here, we synthesized a metal chelator-lipid conjugate enabling positron emission tomography (PET) tracer labeling of LNP/mRNA vaccines for quantitative visualization of vaccine trafficking in live mice and non-human primates (NHPs). Following intramuscular injection, we observed LNPs distributing through injected muscle tissue, simultaneous with rapid trafficking to draining lymph nodes (dLNs).
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November 2022
Department of Chemistry and Biochemistry, St. Mary's College of Maryland, St. Mary's City, MD 20686, USA.
A series of boron, aluminum, gallium, and indium chelates containing the underexplored bis(phenolate) aza-dipyrromethene (aza-DIPY) core were prepared. These compounds were found to possess near-infrared absorption and emission profiles in the 710 to 770 nm domain and exhibit quantum yield values up to 14%. X-ray diffraction analysis revealed that heavier group 13 bis(phenolate) aza-DIPY chelates possessed octahedral geometries with either THF or pyridine groups occupying the axial positions as opposed to the tetrahedral geometry of the boron chelate.
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October 2022
College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
Positron emission tomography (PET) imaging is a powerful non-invasive method to determine the in vivo behavior of biomolecules. Determining biodistribution and pharmacokinetic (PK) properties of targeted therapeutics can enable a better understanding of in vivo drug mechanisms such as tumor uptake, off target accumulation and clearance. Zirconium-89 (Zr) is a readily available tetravalent PET-enabling radiometal that has been used to evaluate the biodistribution and PK of monoclonal antibodies.
View Article and Find Full Text PDFGigascience
August 2022
The Rockefeller University, New York, NY 10065, USA.
Background: Studies in vertebrate genomics require sampling from a broad range of tissue types, taxa, and localities. Recent advancements in long-read and long-range genome sequencing have made it possible to produce high-quality chromosome-level genome assemblies for almost any organism. However, adequate tissue preservation for the requisite ultra-high molecular weight DNA (uHMW DNA) remains a major challenge.
View Article and Find Full Text PDFmBio
February 2022
Department of Molecular Biology, Princeton Universitygrid.16750.35, Princeton, New Jersey, USA.
Quorum sensing (QS) is a chemical communication process in which bacteria produce, release, and detect extracellular signaling molecules called autoinducers. Via combined transcriptional and posttranscriptional regulatory mechanisms, QS allows bacteria to collectively alter gene expression on a population-wide scale. Recently, the TetR family transcriptional regulator LuxT was shown to control Vibrio harveyi 1, encoding the Qrr1 small RNA that functions at the core of the QS regulatory cascade.
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