Cyclic pentapeptides containing the amino acid sequence arginine-glycine-aspartic (RGD) have been widely applied to target αvβ3 integrin, which is upregulated in various tumors during tumor-induced angiogenesis. Multimeric cyclic RGD peptides have been reported to be advantageous over monomeric counterparts for angiogenesis imaging. Here, we prepared mono-, di-, and trimeric cyclic arginine-glycine-aspartic-D-phenylalanine-lysine (c (RGDfK)) derivatives by conjugation with the natural chelator fusarinine C (FSC) using click chemistry based on copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC). The αvβ3 binding properties of 68Ga-labeled mono-, di-, and trimeric c(RGDfK) peptides were evaluated in vitro as well as in vivo and compared with the references monomeric [68Ga]GaNODAGA-c(RGDfK) and trimeric [68Ga]GaFSC(suc-c(RGDfK))3. All 68Ga-labeled c(RGDfK) peptides displayed hydrophilicity (logD = -2.96 to -3.80), low protein binding and were stable in phosphate buffered-saline (PBS) and serum up to 2 h. In vitro internalization assays with human melanoma M21 (αvβ3-positive) and M21-L (αvβ3-negative) cell lines showed specific uptake of all derivatives and increased in the series: mono- < di- < trimeric peptide. The highest tumor uptake, tumor-to-background ratios, and image contrast were found for the dimeric [68Ga]GaMAFC(c(RGDfK)aza)2. In conclusion, we developed a novel strategy for direct, straight forward preparation of mono-, di-, and trimeric c(RGDfK) conjugates based on the FSC scaffold. Interestingly, the best αvβ3 imaging properties were found for the dimeric [68Ga]GaMAFC(c(RGDfK)aza)2.
- MeSH
- Alkynes chemistry MeSH
- Azides chemistry MeSH
- Click Chemistry MeSH
- Peptides, Cyclic chemistry pharmacokinetics MeSH
- Isotope Labeling MeSH
- Copper chemistry MeSH
- Mice MeSH
- Cell Line, Tumor MeSH
- Positron Emission Tomography Computed Tomography MeSH
- Polymerization MeSH
- Gallium Radioisotopes chemistry MeSH
- Siderophores chemistry MeSH
- Tissue Distribution MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
Owing to their tunable blood circulation time and suitable plasma stability, polymer-based nanomaterials hold a great potential for designing and utilising multifunctional nanocarriers for efficient imaging and effective treatment of cancer. When tagged with appropriate radionuclides, they may allow for specific detection (diagnosis) as well as the destruction of tumours (therapy) or even customization of materials, aiming to both diagnosis and therapy (theranostic approach). This review provides an overview of recent developments of radiolabelled polymeric nanomaterials (natural and synthetic polymers) for molecular imaging of cancer, specifically, applying nuclear techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT). Different approaches to radiolabel polymers are evaluated from the methodical radiochemical point of view. This includes new bifunctional chelating agents (BFCAs) for radiometals as well as novel labelling methods. Special emphasis is given to eligible strategies employed to evade the mononuclear phagocytic system (MPS) in view of efficient targeting. The discussion encompasses promising strategies currently employed as well as emerging possibilities in radionuclide-based cancer therapy. Key issues involved in the clinical translation of radiolabelled polymers and future scopes of this intriguing research field are also discussed.
- MeSH
- Isotope Labeling methods MeSH
- Humans MeSH
- Neoplasms * diagnostic imaging radiotherapy MeSH
- Positron-Emission Tomography * MeSH
- Radiopharmaceuticals therapeutic use MeSH
- Single Photon Emission Computed Tomography Computed Tomography * MeSH
- Theranostic Nanomedicine methods MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
For many important research topics in polymer science the use of radionuclides brings significant benefits concerning nanotechnology, polymer drug delivery systems, tissue engineering etc. This contribution describes important achievements of the radionuclide laboratory at Institute of Macromolecular Chemistry of the Academy of Sciences of the Czech Republic (IMC) in the area of polymers for biomedical applications. Particular emphasis will be given to water-soluble polymer carriers of radionuclides, thermoresponsive polymer radionuclide carriers, thermoresponsive polymers for local brachytherapy, polymer scaffolds modified with (radiolabeled) peptides and polymer copper chelators for the therapy of Wilson´s disease.
- MeSH
- Brachytherapy MeSH
- Chelating Agents therapeutic use MeSH
- Hepatolenticular Degeneration drug therapy MeSH
- Humans MeSH
- Copper isolation & purification MeSH
- Drug Carriers * MeSH
- Peptides MeSH
- Polymers * MeSH
- Radioisotopes * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
The direct determination of toxic metal ions, in environmental samples, is difficult because of the latter's presence in trace concentration in association with complex matrices, thereby leading to insufficient sensitivity and selectivity of the methods used. The simultaneous removal of the matrix and preconcentration of the metal ions, through solid phase extraction, serves as the promising solution. The mechanism involved in solid phase extraction (SPE) depends on the nature of the sorbent and analyte. Thus, SPE is carried out by means of adsorption, ion exchange, chelation, ion pair formation, and so forth. As polymeric supports, the commercially available Amberlite resins have been found very promising for designing chelating matrices due to its good physical and chemical properties such as porosity, high surface area, durability and purity. This review presents an overview of the various works done on the modification of Amberlite XAD resins with the objective of making it an efficient sorbent. The methods of modifications which are generally based on simple impregnation, sorption as chelates and chemical bonding have been discussed. The reported results, including the preconcentration limit, the detection limit, sorption capacity, preconcentration factors etc., have been reproduced.
Wilson's disease is a genetic disorder caused by a malfunction of ATPase 7B that leads to high accumulation of copper in the organism and consequent toxic effects. We propose a gentle therapy to eliminate the excessive copper content with oral administration of insoluble non-resorbable polymer sorbents containing selective chelating groups for copper(II). Polymeric beads with the chelating agents triethylenetetramine, N,N-di(2-pyridylmethyl)amine, and 8-hydroxyquinoline (8HQB) were investigated. In a preliminary copper uptake experiment, we found that 8HQB significantly reduced copper uptake (using copper-64 as a radiotracer) after oral administration in Wistar rats. Furthermore, we measured organ radioactivity in rats to demonstrate that 8HQB radiolabelled with iodine-125 is not absorbed from the gastrointestinal tract after oral administration. Non-resorbability and the blockade of copper uptake were also confirmed with small animal imaging (PET/CT) in mice. In a long-term experiment with Wistar rats fed a diet containing the polymers, we have found that there were no signs of polymer toxicity and the addition of polymers to the diet led to a significant reduction in the copper contents in the kidneys, brains, and livers of the rats. We have shown that polymers containing specific ligands could potentially be novel therapeutics for Wilson's disease.
- MeSH
- Administration, Oral MeSH
- Chelating Agents chemistry therapeutic use MeSH
- Gastrointestinal Tract metabolism MeSH
- Hepatolenticular Degeneration drug therapy metabolism MeSH
- Liver metabolism MeSH
- Kidney metabolism MeSH
- Copper metabolism MeSH
- Methylamines chemistry therapeutic use MeSH
- Methylmethacrylates chemistry therapeutic use MeSH
- Brain metabolism MeSH
- Mice MeSH
- Oxyquinoline chemistry therapeutic use MeSH
- Rats, Wistar MeSH
- Pyridines chemistry therapeutic use MeSH
- Trientine chemistry therapeutic use MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Terpolymer bead particles (100-350 microm in diameter) were prepared by suspension radical polymerization from methacrylate esters [2,3-epoxypropyl methacrylate (GMA), 2-(2-hydroxyethoxy)ethyl methacrylate (DEGMA) and ethylene dimethacrylate (EDMA)] and subsequently derivatized affording iminodiacetic acid (IDA) chelating sorbents. The sorbents differed in pore volumes (0-0.7 cm3/g) and specific surface areas (0.03-9.8 m2/g) of their matrices as well as in the amounts of immobilized Ni2+-IDA complexes (0.03-1.58 mmol/g). The binding of imidazole was studied by frontal chromatography to evaluate the accessibility of Ni2+-IDA complexes. It was found that an increase in the bonded imidazole content with increasing immobilized Ni2+-IDA concentration was strongly dependent on the matrix morphology. A higher pore volume of the matrix significantly improved the utilizability of Ni2+-IDA complexes for imidazole binding. The performance of the sorbents based on two porous matrices with immobilized Ni2+-IDA concentration (0.1-1.58 mmol/g) differing in pore size distributions was compared in immobilized metal affinity chromatography (IMAC) of monoclonal mouse immunoglobulin IgG1 specific against human choriogonadotropic hormone (GTH-spec IgG1). The results have shown that sorbents based on matrix with large pores (up to 20 microm in diameter) exhibited high protein binding capacities. The GTH-spec IgG1 (Mw=158,000) was eluted from all the sorbents in its native form as was confirmed by MALDI-TOF.
- MeSH
- Chelating Agents chemistry MeSH
- Chorionic Gonadotropin immunology MeSH
- Chromatography, Affinity MeSH
- Epoxy Compounds chemistry MeSH
- Financing, Organized MeSH
- Genes, Immunoglobulin MeSH
- Imidazoles chemistry MeSH
- Imino Acids chemistry MeSH
- Humans MeSH
- Methacrylates chemistry MeSH
- Antibodies, Monoclonal chemistry MeSH
- Mice MeSH
- Nickel MeSH
- Polymers chemistry MeSH
- Porosity MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
