Related Experiment Video
Updated: Jan 12, 2026
10:54
Preparation and Evaluation of 99mTc-labeled Tridentate Chelates for Pre-targeting Using Bioorthogonal Chemistry
Published on: February 4, 2017
8.6K
Investigating Metal and Fluorophore Controlled Intracellular Localization in Noble Metal Thiosemicarbazone Complexes
Nandan Sheernaly1, Axel Steinbrueck1, Nicolas Krahn1
1Faculty of Chemistry and Biochemistry, Inorganic Chemistry I - Bioinorganic Chemistry, Ruhr University Bochum, Universitaetsstrasse 150, Bochum, 44801, Germany.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|November 5, 2025
Summary
This study reveals that the metal center identity significantly impacts cellular imaging tool localization. Changing the metal in isostructural complexes affects organelle specificity, offering new design insights.
Area of Science:
- Inorganic Chemistry
- Bioinorganic Chemistry
- Chemical Biology
Background:
- Transition metal complexes are valuable cellular imaging tools.
- Organelle specificity is typically achieved by modifying ligand architecture (charge, lipophilicity).
- The influence of the metal center's intrinsic properties on localization is often overlooked.
Purpose of the Study:
- To investigate the effect of varying metal centers on the subcellular localization of isostructural thiosemicarbazone complexes.
- To explore the interplay between metal identity, ligand properties, and cellular distribution patterns.
- To assess the impact of different fluorophores on localization.
Main Methods:
- Synthesis of coumarin- and BODIPY-conjugated thiosemicarbazone (Dp44mT) complexes of Au(III), Pt(II), and Pd(II).
- Characterization of isostructural complexes with differing metal centers (Au, Pt, Pd).
- Confocal microscopy to determine intracellular localization of the synthesized metal complexes.
Main Results:
- Metal complexes exhibited distinct intracellular distributions.
- The coumarin-conjugated Pt(II) complex showed specific lysosomal localization.
- The lipophilic Pd(II) complex displayed a diffuse cytosolic distribution, lacking specificity.
- More lipophilic BODIPY-conjugated complexes also showed non-specific cellular distribution.
Conclusions:
- Metal identity, alongside lipophilicity, plays a crucial role in determining the cellular localization of Dp44mT-based metal complexes.
- Findings provide new perspectives for designing targeted metal-based cellular imaging agents.
- The choice of metal center is a critical factor in achieving organelle-specific imaging.
Related Concept Videos
02:51Metal-Ligand Bonds
23.9K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
23.9K
01:09Complexation Equilibria: Factors Influencing Stability of Complexes
781
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
781
01:19Complexation Equilibria: The Chelate Effect
1.2K
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
1.2K
03:45Formation of Complex Ions
25.6K
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
25.6K
02:42Valence Bond Theory
11.2K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
11.2K
00:56Extraction: Advanced Methods
1.1K
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is...
1.1K