tellurium and Glioblastoma

As the early detection and total destruction of gliomas are essential for longer survival, we attempted to synthesize a quantum dot (QD) that is capable of recognizing glioma cells for imaging and photodynamic therapy.. Using a one-pot aqueous approach, near infrared-emitting CdTe was produced. After detection of its physicochemical characteriistics, it was conjugated with RGD. The emission images were observed with confocal microscopy. To test its toxicity, CdTe-RGD at various concentrations was separately added to a human glioma cell line (U251) and a mouse embryo fibroblast cell line (3T3) (control) for incubation in dark conditions. To test its photodynamic effect, the U251 and 3T3 cells were then irradiated for 5-60 min, using a 632.8-nm laser.. This QD (Φ = 3.75 nm, photoluminescence (PL) peak wavelength = 700 nm, photoluminescence quantum yield (PLQY) = 20 %), was a spherical crystal with excellent monodispersity. Under a confocal microscope, U251 cells were visualized, but not the 3T3 cells. In dark conditions, the survival rates of both U251 and 3T3 cells were above 85 %. After laser irradiation, the survival rate of U251 cells decreased to 37 ± 1.6 % as the irradiation time and the CdTe-RGD concentration were increased.. With good physicochemical characteriistics and low toxicity, this QD-RGD has broad prospects for use in the biomedical imaging and photodynamic therapy of gliomas.

Topics: 3T3 Cells; Animals; Antineoplastic Agents; Brain Neoplasms; Cadmium Compounds; Cell Line, Tumor; Cell Survival; Glioblastoma; Glioma; Humans; In Vitro Techniques; Low-Level Light Therapy; Mice; Microscopy, Confocal; Oligopeptides; Photochemotherapy; Quantum Dots; Tellurium

A 70-year-old man underwent a thallium-201 brain SPECT in the work-up and characterization of a frontotemporal mass. SPECT images were performed on cadmium zinc telluride system during only 5 minutes and after the injection of only 2 mCi. Images demonstrated high thallium uptake in frontotemporal areas considered as a potential malignant tumor. Surgical removal confirmed the diagnosis of malignant glioblastoma. The thallium SPECT fast acquisition imaging on cadmium zinc telluride systems is feasible with reduced injected dose. This method allows a significantly decrease of patient radiation exposure without compromising the image quality. This initial experience needs to be confirmed and optimized in larger clinical studies.

Topics: Aged; Brain; Cadmium; Glioblastoma; Humans; Male; Tellurium; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Zinc

In novel treatment approaches, therapeutics should be designed to target cancer stem cells (CSCs). Quantum dots (QDs) are a promising new tool in fighting against cancer. However, little is known about accumulation and cytotoxicity of QDs in CSCs.. Accumulation and cytotoxicity of CdTe-MPA (mercaptopropionic acid) QDs in CSCs were assessed using flow cytometry and fluorescence-activated cell sorting techniques as well as a colorimetric cell viability assay.. We investigated the expression of two cell surface-associated glycoproteins, CD44 and CD133, in four different cancer cell lines (glioblastoma, melanoma, pancreatic, and prostate adenocarcinoma). Only the melanoma cells were positive to both markers of CD44 and CD133, whereas the other cells were only CD44-positive. The QDs accumulated to a similar extent in all subpopulations of the melanoma cells. The phenotypical response after QD treatment was compared with the response after ionizing radiation treatment. The percentage of the CD44(high-)CD133(high) subpopulation decreased from 72% to 55%-58% for both treatments. The stem-like subpopulation CD44(high)CD133(low/-) increased from 26%-28% in the untreated melanoma cells to 36%-40% for both treatments.. Treatment of melanoma cells with QDs results in an increase of stem-like cell subpopulations. The changes in phenotype distribution of the melanoma cells after the treatment with QDs are comparable with the changes after ionizing radiation.

Topics: 3-Mercaptopropionic Acid; AC133 Antigen; Antigens, CD; Biomarkers, Tumor; Cadmium Compounds; Cell Line, Tumor; Cell Survival; Flow Cytometry; Glioblastoma; Glycoproteins; Humans; Hyaluronan Receptors; Male; Melanoma; Neoplastic Stem Cells; Pancreatic Neoplasms; Peptides; Phenotype; Prostatic Neoplasms; Quantum Dots; Tellurium