tellurium and Neoplasms

Selenium is an essential trace element that is crucial for cellular antioxidant defense against reactive oxygen species (ROS). Recently, many selenium-containing compounds have exhibited a wide spectrum of biological activities that make them promising scaffolds in Medicinal Chemistry, and, in particular, in the search for novel compounds with anticancer activity. Similarly, certain tellurium-containing compounds have also exhibited substantial biological activities. Here we provide an overview of the biological activities of seleno- and tellurocompounds including chemopreventive activity, antioxidant or pro-oxidant activity, modulation of the inflammatory processes, induction of apoptosis, modulation of autophagy, inhibition of multidrug efflux pumps such as P-gp, inhibition of cancer metastasis, selective targeting of tumors and enhancement of the cytotoxic activity of chemotherapeutic drugs, as well as overcoming tumor drug resistance. A review of the chemistry of the most relevant seleno- or tellurocompounds with activity against resistant cancers is also presented, paying attention to the synthesis of these compounds and to the preparation of bioactive selenium or tellurium nanoparticles. Based on these data, the use of these seleno- and tellurocompounds is a promising approach in the development of strategies that can drive forward the search for novel therapies or adjuvants of current therapies against drug-resistant cancers.

Topics: Antineoplastic Agents; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Humans; Nanoparticles; Neoplasms; Reactive Oxygen Species; Selenium; Tellurium

Semiconductor quantum dots (QDs) are light-emitting particles on the nanometer scale that have emerged as a new class of fluorescent labels for chemical analysis, molecular imaging, and biomedical diagnostics. Compared with traditional fluorescent probes, QDs have unique optical and electronic properties such as size-tunable light emission, narrow and symmetric emission spectra, and broad absorption spectra that enable the simultaneous excitation of multiple fluorescence colors. QDs are also considerably brighter and more resistant to photobleaching than are organic dyes and fluorescent proteins. These properties are well suited for dynamic imaging at the single-molecule level and for multiplexed biomedical diagnostics at ultrahigh sensitivity. Here, we discuss the fundamental properties of QDs; the development of next-generation QDs; and their applications in bioanalytical chemistry, dynamic cellular imaging, and medical diagnostics. For in vivo and clinical imaging, the potential toxicity of QDs remains a major concern. However, the toxic nature of cadmium-containing QDs is no longer a factor for in vitro diagnostics, so the use of multicolor QDs for molecular diagnostics and pathology is probably the most important and clinically relevant application for semiconductor QDs in the immediate future.

Topics: Biomarkers, Tumor; Cadmium Compounds; Diagnostic Imaging; DNA; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Male; Nanoparticles; Nanotechnology; Neoplasms; Polyethylene Glycols; Prostate; Quantum Dots; Selenium Compounds; Semiconductors; Tellurium

Gamma probes have been used for sentinel lymph node biopsy in melanoma and breast cancer. However, these probes can provide only radioactivity counts and variable pitch audio output based on the intensity of the detected radioactivity. We have developed a small semiconductor gamma camera (SSGC) that allows visualisation of the size, shape and location of the target tissues. This study is designed to characterise the performance of the SSGC for radioguided surgery of metastatic lesions and for other imaging applications amenable to the smaller format of this prototype imaging system. The detector head had 32 cadmium telluride semiconductor arrays with a total of 1,024 pixels, and with application-specific integrated circuits (ASICs) and a tungsten collimator. The entire assembly was encased in a lead housing measuring 152 mmx166 mmx65 mm. The effective visual field was 44.8 mmx44.8 mm. The energy resolution and imaging aspects were tested. Two spherical 5-mm- and 15-mm-diameter technetium-99m radioactive sources that had activities of 0.15 MBq and 100 MBq, respectively, were used to simulate a sentinel lymph node and an injection site. The relative detectability of these foci by the new detector and a conventional scintillation camera was studied. The prototype was also examined in a variety of clinical applications. Energy resolution [full-width at half-maximum (FWHM)] for a single element at the centre of the field of view was 4.2% at 140 keV (99mTc), and the mean energy resolution of the CdTe detector arrays was approximately 7.8%. The spatial resolution, represented by FWHM, had a mean value of 1.56 +/- 0.05 mm. Simulated node foci could be visualised clearly by the SSGC using a 15-s acquisition time. In preliminary clinical tests, the SSGC successfully imaged diseases in a variety of tissues, including salivary and thyroid glands, temporomandibular joints and sentinel lymph nodes. The SSGC has significant potential for diagnosing diseases and facilitating subsequent radioguided surgery.

Topics: Aged; Cadmium Compounds; Equipment Design; Equipment Failure Analysis; Feasibility Studies; Female; Gamma Cameras; Humans; Lymph Nodes; Male; Neoplasms; Phantoms, Imaging; Pilot Projects; Reproducibility of Results; Sensitivity and Specificity; Sentinel Lymph Node Biopsy; Signal Processing, Computer-Assisted; Single-Blind Method; Surgery, Computer-Assisted; Tellurium; Tomography, Emission-Computed

A photoelectrochemical (PEC) immunosensor based on MIL-101(Cr) and CdTe-QDs composites (M&C) was successfully synthesized to assay the carcinoembryonic antigen (CEA) in human serum and urine samples. This novel method contained three key aspects: 1), the polarity of the photocurrent based on MIL-101(Cr) itself could be altered by applying a different voltage to detect the cathode and anode photocurrent. 2), the introduction of cadmium telluride quantum dots (CdTe-QDs) greatly improved the efficiency of light utilization. 3), the photogenerated electron-hole-pairs were suppressed and their separation efficiency was improved by effective matching of energy level between MIL-101(Cr) and CdTe-QDs. Due to the inherent insulating properties of the biological matrix, the transfer of photogenerated electrons was hindered, leading to a decreased photocurrent signal. Under the optimal condition, the anodic and cathodic detection limit of the PEC immunosensor for CEA was 0.00018 ng mL

Topics: Biosensing Techniques; Cadmium Compounds; Carcinoembryonic Antigen; Early Detection of Cancer; Humans; Immunoassay; Neoplasms; Quantum Dots; Tellurium

Probiotic Escherichia coli Nissle 1917 (EcN) are employed as a bioreactor for intracellularly synthesizing tellurium nanorods (TeNRs) providing a biohybrid therapeutic platform (Te@EcN) for the elimination of advanced malignant tumor by photothermal immunotherapy. Te@EcN is found to possess superior photothermal property upon near-infrared irradiation, and can efficiently accumulate and retain in tumors, although EcN loses proliferation ability after the synthesis of TeNRs, thus inducing considerable immunogenic tumor cell death. Under co-stimulation by EcN acting as immunoadjuvants, maturation of dendritic cells and priming of cytotoxic T cells are largely promoted. In addition, Te@EcN can reprogram tumor-associated macrophages to ameliorate the immunosuppressive tumor microenvironment. Thus, tumor metastasis and recurrence can be efficiently suppressed. Most importantly, owing to the non-pathogenicity of probiotic EcN and their non-proliferative characteristics after TeNRs synthesis, Te@EcN is found to be rapidly metabolized and cleared from the normal tissues, showing very slight acute side effects in healthy mice even at a relatively high administration dose. Therefore, the proposed combined therapeutic strategy based on bacteria-synthesized TeNRs may find great potential in improving bacteria-mediated tumor therapy with increased antitumor efficacy and reduced toxicity.

Topics: Animals; Immunotherapy; Mice; Nanotubes; Neoplasms; Tellurium; Tumor Microenvironment

Inducing apoptosis in cancer cells is considered a potential therapeutic mechanism underlying cancers. Here, chiral folic acid (FA) conjugated Cys-CdTe/CdS quantum dots (QDs) conjugated with a cancer-targeting ligand were fabricated to induce apoptosis in vivo. Ligand-induced chirality mechanism for FA-Cys-CdTe/CdS QDs was discussed, which is verified by density functional theory (DFT) simulation. Interestingly, we found that the circular dichroism (CD) signals of chiral QDs can effectively distinguish breast cancer cells from normal cells, where a sharp decrease in CD signal and absorption intensity can be seen. Notably, chiral FA-Cys-CdTe/CdS QDs showed significant apoptosis-inducing ability after the release of mitochondrial apoptotic factors. Furthermore, in vivo experiments showed that chiral FA-Cys-CdTe/CdS QDs provide an efficient cancer ablation through the apoptosis process with negligible toxicity, demonstrating their great potential utility in targeted anticancer agent for future clinic application.

Topics: Cadmium Compounds; Folic Acid; Ligands; Neoplasms; Quantum Dots; Tellurium

Rh is a noble metal introduced in bioapplications, including diagnosis and therapy, in addition to its consolidated utilization in organic catalysis and electrocatalysis. Herein, we designed the synthesis of highly crystalline Rh nanocrystal-decorated Rh-Te nanorods (RhTeNRs) through galvanic replacement of sacrificial Te nanorod (TeNR) templates and subsequent polyol regrowth. The obtained RhTeNRs showed excellent colloidal stability and efficient heat dissipation and photocatalytic activity under various laser irradiation wavelengths. Based on the confirmed biocompatibility, RhTeNRs were introduced into

Topics: Animals; Mice; Mice, Inbred BALB C; Nanotubes; Neoplasms; Phototherapy; Polymers; Rhodium; Tellurium

Sensitive and accurate detection of cancer cells is of great significance for the early diagnosis and treatment of cancer. In this work, we developed a simple fluorescent signal amplification biosensor based on an entropy-driven three-dimensional (3D) multipedal-DNA walker for highly sensitive detection of cancer cells. Firstly, DNA tetrahedron nanostructures (DTNs) combined with AS1411 aptamer were used as the capture probe to achieve efficient capture of cancer cells. Then, the bipedal hairpin fuel chain hybridized with DTNs and exposed two catalytic "legs" to form a walker probe. Finally, the walker probe autonomously walked on polystyrene microspheres (PS) via entropy-driven catalytic reaction. DTNs rolled on the PS to achieve multipedal walking, realizing fluorescence signal amplification due to fluorescence recovery of DNA-CdTe quantum dots on the PS surface. This fluorescence signal amplification strategy showed excellent selectivity and sensitivity toward cancer cells with the detection limit of 7 cell mL

Topics: Biomarkers, Tumor; Cadmium Compounds; DNA; Entropy; Limit of Detection; Neoplasms; Polystyrenes; Quantum Dots; Tellurium

Sulfur bonds, especially trisulfide bond, have been found to ameliorate the self-assembly stability of homodimeric prodrug nanoassemblies and could trigger the sensitive reduction-responsive release of active drugs. However, the antitumor efficacy of homodimeric prodrug nanoassemblies with single reduction-responsivity may be restricted due to the heterogeneous tumor redox microenvironment. Herein, we replace the middle sulfur atom of trisulfide bond with an oxidizing tellurium atom or selenium atom to construct redox dual-responsive sulfur-tellurium-sulfur and sulfur-selenium-sulfur hybrid chalcogen bonds. The hybrid chalcogen bonds, especially the sulfur-tellurium-sulfur bond, exhibit ultrahigh dual-responsivity to both oxidation and reduction conditions, which could effectively address the heterogeneous tumor microenvironment. Moreover, the hybrid sulfur-tellurium-sulfur bond promotes the self-assembly of homodimeric prodrugs by providing strong intermolecular forces and sufficient steric hindrance. The above advantages of sulfur-tellurium-sulfur bridged homodimeric prodrug nanoassemblies result in the improved antitumor efficacy of docetaxel with satisfactory safety. The exploration of hybrid chalcogen bonds in drug delivery deepened insight into the development of prodrug-based chemotherapy to address tumor redox heterogeneity, thus enriching the design theory of prodrug-based nanomedicines.

Topics: Drug Liberation; Humans; Neoplasms; Oxidation-Reduction; Prodrugs; Selenium; Sulfur; Tellurium; Tumor Microenvironment

Tumor cells can be selectively killed by heat application based on the different tolerances of normal cells and tumor cells to temperature. However, the limited clinical application of photothermal therapy (PTT) is mainly due to various practical implementation difficulties, of which the most important is how to fully heat the tumor. The combination of PTT and chemotherapy can synergistically enhance cell membrane permeability and reduce the dose of chemotherapy drugs to not only effectively kill the tumor but also reduce the damage to normal tissues. It is of great significance to develop materials that can be simultaneously used for tumor PTT and chemotherapy. Therefore, in this study, a functionalized tellurium (Te) nanosystem (DOX/PEI@TeNPs) was prepared to achieve chemo-photothermal cancer combination therapy. Our research showed that the DOX/PEI@TeNP morphology was controllable, and it had good photothermal conversion efficiency and light stability. Moreover, DOX/PEI@TeNPs containing doxorubicin (DOX) showed almost no drug release in normal tissues and neutral-pH environments, while in tumor cells and tissues, it massively released DOX to kill cancer cells. The as-synthesized DOX/PEI@TeNP system can produce reactive oxygen species (ROS) under near-infrared (NIR) light irradiation and features a high photothermal conversion efficiency due to its strong NIR absorbance. Therefore, this study provides an effective strategy for the effective design of nano-drugs, which can be used for the accurate chemical-photothermal synergistic therapy of tumors.

Topics: Cell Line, Tumor; Doxorubicin; Drug Liberation; Hyperthermia, Induced; Lasers; Nanoparticles; Neoplasms; Tellurium

The specific identification and elimination of cancer cells has been a great challenge in the past few decades. In this study, the circular dichroism (CD) of cells was measured by a self-designed special system through the folate-conjugated chiral nano-sensor. A novel method was established to recognize cancer cells from normal cells according to the chirality of cells based on their CD signals. After a period of interaction between the nano-sensor and cells, the sharp weakening of CD signals was induced in cancer cells but normal cells remained unchanged. The biocompatibility of the nano-sensor was evaluated and the result showed that it exhibited significant cytotoxic activity against cancer cells while no obvious damage on normal cells. Notably, the research indicated that the nano-sensor may selectively cause apoptosis in cancer cells, and thus, have the potential to act as an antitumor agent.

Topics: Apoptosis; Breast Neoplasms; Cadmium Compounds; Cell Line, Tumor; Circular Dichroism; Female; Folic Acid; Humans; Neoplasms; Quantum Dots; Sulfides; Tellurium

Proton neutron gamma-x detection (PNGXD) is a novel imaging concept being investigated for tumor localization during proton therapy that uses secondary neutron interactions with a gadolinium contrast agent (GDCA) to produce characteristic photons within the 40-200 keV energy region. The purpose of this study is to experimentally investigate the feasibility of implementing this procedure by performing experimental measurements on a passive double scattering proton treatment unit. Five experimental measurements were performed with varying concentrations and irradiation conditions. Photon spectra were measured with a 25 mm

Topics: Cadmium Compounds; Contrast Media; Feasibility Studies; Gadolinium; Gamma Rays; Humans; Monte Carlo Method; Neoplasms; Neutrons; Phantoms, Imaging; Proton Therapy; Quantum Dots; Tellurium

The aim of this work was to assess the performance of a prototype compact gamma camera (MediPROBE) based on a CdTe semiconductor hybrid pixel detector, for coded aperture imaging. This probe can be adopted for various tasks in nuclear medicine such as preoperative sentinel lymph node localization, breast imaging with

Topics: Cadmium Compounds; Gamma Cameras; Gamma Rays; Humans; Neoplasms; Phantoms, Imaging; Photons; Radionuclide Imaging; Radiosurgery; Reproducibility of Results; Semiconductors; Signal-To-Noise Ratio; Tellurium

Au-Te-clustered nanoworms (AuTeNWs) were successfully synthesized under ambient conditions by spontaneous galvanic replacement using Te nanorods as a sacrificial nanotemplate. Along with the gradual replacement and on-surface crystalline Au cluster formation, Te nanotemplates were transformed into a serpentine nanoworm-like morphology. The present strategy was an environmentally friendly method that did not use surfactants to control the surface structure. The synthesized nanoworms exhibited excellent photothermal conversion, photocatalytic efficiencies, and high payloads for thiolated genes and cell-penetrating peptides. According to the visible and near-infrared wavelengths of light, the photodynamic and photothermal therapeutic pathways were dominantly acting, respectively. From this, wavelength-selective combination treatment with gene therapy was successfully accomplished. Taken together, excellent therapeutic effects for in vitro and in vivo mouse models against hepatitis C replicon human hepatocarcinoma were clearly identified by using the present AuTeNWs as a phototherapeutic nanocarrier.

Topics: Animals; Antineoplastic Agents; Cell Line; Cell Survival; Electrochemical Techniques; Gold; Humans; Male; Metal Nanoparticles; Mice; Mice, Inbred BALB C; Neoplasms; Photochemotherapy; Tellurium

A method is described for the simultaneous determination of hepatocellular carcinoma-associated microRNA-122 and microRNA-199a/b-3p. This probe consists of two kinds of nanomaterials. The first comprises CdTe@CdS core-shell quantum dots which, on excitation at 375 nm give two emissions, with peak wavelengths at 543 (g-QDs) and at 627 nm (r-QDs). The second comprises gold nanoparticles acting as a quencher. In the absence of the target, g-QD-N1 and r-QD-N2 are stable due to the fluorescence stability. With the addition of microRNA-122 and microRNA-199a/b-3p, g-QD-N1 and r-QD-N2 are conjugated to the surface of AuNP-S1/S2 through base complementary pairing. As a result, fluorescence resonance energy transfer (FRET) occurs, resulting in a decrease at 550 nm and 635 nm respectively, which can realize the simultaneous detection of two different microRNAs. Detection is achieved within 50 min. The detection limits (3σ/k) are 0.2 nM for microRNA-122 and 0.5 nM for microRNA-199a/b-3p. The clinical applicability of the assay was demonstrated by detecting microRNAs in human serum and different cell lysates. Graphical abstractSchematic for the simultaneous determination of microRNA-122 and microRNA-199a/b-3p by FRET.

Topics: Biosensing Techniques; Cadmium Compounds; Carcinoma, Hepatocellular; Fluorescence Resonance Energy Transfer; Fluorometry; Humans; Limit of Detection; Liver Neoplasms; MicroRNAs; Neoplasms; Nucleic Acid Hybridization; Quantum Dots; Sulfides; Tellurium

Radionuclide angiography is widely used for left ventricular function assessment. This study establishes normative data and inter-study repeatability on peak ventricular filling and emptying rates obtained by a cadmium-zinc-telluride SPECT camera.. Cancer patients (N = 764) without diabetes or cardiovascular diseases referred for baseline assessment of cardiac function were included. Repeatability was assessed in 46 patients where two separate acquisitions were performed. Left and right ventricular emptying rates (LPER, RPER) and filling rates (LPFR, RPFR) were obtained and whenever possible also atrial filling rates (PFR. Filling rates were higher in women than men. Emptying rates tended to increase with age, whereas filling rates and the E/A ratio decreased. One patient was excluded from the repeatability analysis due to an unexplained high intra-observer variation. Intraclass correlation coefficients for LPER, RPER, LPFR, and RPFR were 0.99, 0.94, 0.99, and 0.84, no proportional biases were detected.. Reference values and relations to age and gender in chemotherapy-naïve cancer patients without cardiopulmonary disease are presented. The CZT camera provides reproducible estimates of peak emptying and filling rates.

Topics: Adult; Age Factors; Aged; Cadmium; Diastole; Female; Gamma Cameras; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Neoplasms; Sex Characteristics; Tellurium; Tomography, Emission-Computed, Single-Photon; Ventricular Function; Zinc

Topics: Antineoplastic Agents; Cadmium; Cardiotoxicity; Humans; Neoplasms; Radionuclide Angiography; Tellurium; Tomography, Emission-Computed, Single-Photon; Zinc

A electrochemical biosensing strategy was developed for green and ultrasensitive detection of tumor cells by combining aptamer-DNA concatamer-CdTe quantum dots (QDs) signal amplification probe with mercury-free anodic stripping voltammetry (ASV). First, aptamer-DNA concatamer- CdTe QDs probes were designed by DNA hybridization and covalent assembling, which contained specific recognition of aptamer and signal amplification incorporating the DNA concatamer with QDs. Meanwhile, the capture electrode, glassy carbon electrode (GCE)/Graphene oxide (GO)/Polyaniline (PANI) / Glutaraldehyde (GA) / concanavalin A (Con A) was fabricated by a layer-by-layer assembling technique. K562 cells, as model cancer cells were detected to demonstrate the feasibility of this sensing strategy. Then, novel composite, graphene (GR)- Poly diallyldimethylammonium chloride (PDDA)/L-Cysteine (L- Cys), was explored in ASV which replaced mercury electrodes using for determination of tumor cells. The proposed electrochemical biosensor showed high sensitivity with the detection limit of 60 cells mL

Topics: Aptamers, Nucleotide; Biosensing Techniques; Cadmium Compounds; Cell Line, Tumor; Cell Separation; DNA Probes; Electrochemical Techniques; Graphite; Humans; Limit of Detection; Mercury; Neoplasms; Quantum Dots; Tellurium

A multifunctional DNA nanocage containing CdTe quantum dots (QDs) was prepared. It was applied to the fluorometric detection of human 8-oxoG DNA glycosylase 1 (hOGG1) by exonuclease-assisted cycling amplification technique. When loaded with the cancer drug doxorubicin (Dox), the nanocage is also a versatile probe for fluorescence imaging of cancer cells, and drug delivery to them. The presence of hOGG1 leads to the division of DNA HP1 (containing 8-oxo-dG) and formation of DNA fragments 1 and 2. Then, HP2 is added to hybridize with DNA 1 and produced lots of trigger DNA (containing nucleolin aptamer) by Exo III-aided cycling amplification. The DNA nanocage was fabricated by linking the trigger DNA to multiple specific DNA strands, and the fluorescent CdTe QDs were further conjugated to the DNA nanocage for sensitive detection of hOGG1 activity. After Dox is incorporated into the DNA nanocage, the fluorescence of Dox is turned off. Once the DNA nanocage enters the MCF-7 cells, the Dox is released and its fluorescence (measured at excitation/emission wavelengths of 480/560 nm) is turned on. The DNA nanocage containing fluorescent QDs and Dox was successfully applied to the fluorometric detection of hOGG1, fluorescence imaging, and therapy of cancer cells, which has great promise in clinical application and treatment of cancer. Graphical abstract A multifunctional DNA nanocage containing CdTe quantum dots and acting as a signalling probe was prepared. It was applied to fluorometric determination of human 8-oxoG DNA glycosylase 1 using cycling amplification technique. It also enables drug delivery to cancer cells if loaded with doxorubicin.

Topics: Cadmium Compounds; Diagnostic Imaging; DNA; DNA Glycosylases; Doxorubicin; Drug Delivery Systems; Fluorescence; Fluorescent Dyes; Fluorometry; Humans; Neoplasms; Quantum Dots; Tellurium

To determine whether the left ventricular ejection fractions (EFs), measured on a high-sensitivity CZT single photon emission computed tomography (SPECT)-camera with a 70% reduction in recording times and a prevention of EF overestimation through an additional count-calibration, are concordant with reference EF from planar radionuclide angiography (2D-RNA).. An additional 10-minute CZT-SPECT recording was performed in patients referred to 2D-RNA for cardiomyopathy (n = 23) or chemotherapy monitoring (n = 50) with an in vivo red blood cell labeling with 850 MBq [Formula: see text]. The EF, obtained from CZT-SPECT with 100% (SPECT100) or 30% (SPECT30) projection times and with a SPECT-count calibration on the 2D-RNA counts of corresponding cavity volumes, were compared to EF from 2D-RNA.. Strong and equivalent relationships were documented between the EF from 2D-RNA and the calibrated EF from SPECT100 (y = 0.89x + 6.62; R. Left ventricular EF may be determined on a high-sensitivity CZT-camera, a 70% reduction in injected activities, and an additional count-calibration for further enhancing the concordance with 2D-RNA values.

Topics: Adult; Aged; Angiography; Antineoplastic Agents; Cadmium; Calibration; Cardiomyopathies; Computer Simulation; Erythrocytes; Female; Gamma Cameras; Heart Ventricles; Humans; Male; Middle Aged; Neoplasms; Prospective Studies; Radionuclide Angiography; Stroke Volume; Tellurium; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left; Zinc

The next step in the boron neutron capture therapy (BNCT) is the real time imaging of the boron concentration in healthy and tumor tissue. Monte Carlo simulations are employed to predict the detector response required to realize single-photon emission computed tomography in BNCT, but have failed to correctly resemble measured data for cadmium telluride detectors. In this study we have tested the gamma production cross-section data tables of commonly used libraries in the Monte Carlo code MCNP in comparison to measurements. The cross section data table TENDL-2008-ACE is reproducing measured data best, whilst the commonly used ENDL92 and other studied libraries do not include correct tables for the gamma production from the cadmium neutron capture reaction that is occurring inside the detector. Furthermore, we have discussed the size of the annihilation peaks of spectra obtained by cadmium telluride and germanium detectors.

Topics: Boron; Boron Neutron Capture Therapy; Cadmium Compounds; Computer Simulation; Humans; Isotopes; Monte Carlo Method; Neoplasms; Phantoms, Imaging; Radiometry; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Spectrometry, Gamma; Tellurium; Tomography, Emission-Computed, Single-Photon

Topics: Animals; Antibiotics, Antineoplastic; Cadmium Compounds; Delayed-Action Preparations; Doxorubicin; Gadolinium; HeLa Cells; Humans; Hydrogen-Ion Concentration; Magnetic Resonance Imaging; Mice; Nanocomposites; Neoplasms; Optical Imaging; Permeability; Quantum Dots; Tellurium; Theranostic Nanomedicine; Yolk Sac

Tumor therapy using nanoparticles (NPs) is mainly aimed at using the NPs as carriers for therapeutic drugs or as mediators for external stimuli to generate heat. Recent studies have shown that the toxicity of NPs can also be specifically exploited to kill cancer cells. In the present work, we employ core-only CdTe quantum dots and study their cytotoxicity using a validated high-content screening approach. The data revealed a clear correlation between toxicity and quantum dot degradation, which could be monitored through loss of fluorescence intensity. Based on the in vitro data obtained, the in vivo dose was calculated relative to the estimated number of tumor cells based on luminescence measurements. The obtained results show a clear increase in reproducibility of the therapeutic effect compared to normal conditions, where a set dose of quantum dots was administered regardless of the tumor size. The therapeutic delivery could also be monitored in vivo, where the loss of fluorescence intensity correlated with the anticancer efficacy. The present work highlights the benefits of noninvasive imaging to monitor therapeutic delivery and to optimize treatment via personalized medicine.

Topics: Animals; Cadmium Compounds; Cell Death; Cell Line, Tumor; Cell Proliferation; Drug Delivery Systems; Female; Fluorescence; Humans; Luciferases; Luminescent Measurements; Mice; Models, Theoretical; Neoplasms; Optical Imaging; Precision Medicine; Quantum Dots; Tellurium

Multimodal imaging has made great contribution for diagnosis and therapy of disease since it can provide more effective and complementary information in comparison to any single imaging modality. The design and fabrication of fluorescent-magnetic nanoparticles for multimodal imaging has rapidly developed over the years. Herein, we demonstrate the facile synthesis of GdS coated CdTe nanoparticles (CdTe@GdS NPs) as multimodal agents for fluorescence (FL) and T1-weighted magnetic resonance (MR) imaging. These nanoparticles obtain both prominent fluorescent and paramagnetic properties by coating the GdS shell on the surface of CdTe core via a simple room-temperature route in aqueous solution directly. It is shown that the as-prepared CdTe@GdS NPs have high quantum yield (QY) value of 12% and outstanding longitudinal relaxation rate (r1) of 11.25 mM s(-1), which allow them to be employed as FL/MR dual-modal imaging contrast agents. They also exhibit small particle size of 5 nm, excellent colloidal stability and low cellular toxicity for concentrations up to 750 μg mL(-1). In addition, with the conjugation of folic acid, the nanoparticles were successfully used for tumor-targeted FL/MR dual-modal imaging in vitro and in vivo.

Topics: Animals; Cadmium Compounds; Cell Survival; Fluorescent Dyes; Gadolinium; Humans; KB Cells; Magnetite Nanoparticles; Mice; Mice, Inbred BALB C; Mice, Nude; Microscopy, Electron, Transmission; Microscopy, Fluorescence; Neoplasms; Spectroscopy, Fourier Transform Infrared; Sulfides; Tellurium

An efficient approach for the synthesis of Z-1,3-enynes based on the coupling reaction of Z-vinyl tellurides and alkynes containing a pseudoglycoside moiety is described. The products were obtained in good yields via a stereoselective way. Preliminary screening against three tumor cell lines indicated that the synthesized compounds are promising intermediates for the synthesis of an array of more potent target structures.

Topics: Alkynes; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Cell Survival; Glycosides; Humans; Neoplasms; Stereoisomerism; Tellurium; Vinyl Compounds

Fiberoptic dosimetry (FOD) is an experimental technique suitable for in-vivo, real time dosimetry in radiotherapy treatments. FOD relies on using a small scintillator coupled to one end of a long optical fiber. The scintillator is placed at the point where the dose rate is to be determined whereas a light detector at the other end of the fiber measures the intensity of the radioluminescence emitted by the scintillator. One of the problems hampering the straightforward application of this technique in clinics is the presence of Cherenkov radiation generated in the fiber by the ionizing radiation, which adds to the scintillating light and introduces a bias in the dose measurement. Since Cherenkov radiation is more important in short wavelength range of the visible spectrum, using red-emitting scintillators as FOD detectors permits to reduce the Cherenkov contribution by using optical filters. In this work, the performance of red-emitting tellurium-doped zinc selenide crystal as FOD detector is evaluated and compared to the response of an ion-chamber.

Topics: Computer Systems; Fiber Optic Technology; Humans; Luminescent Measurements; Neoplasms; Optical Fibers; Radiometry; Radiosurgery; Radiotherapy Dosage; Scintillation Counting; Selenium Compounds; Tellurium; Zinc Compounds

Local and rapid heating by microwave (MW) irradiation is important in the clinical treatment of tumors using hyperthermia. We report here a new thermo-seed technique for the highly efficient MW irradiation ablation of tumors in vivo based on gelatin microcapsules. We achieved 100% tumor elimination in a mouse model at an ultralow power of 1.8 W without any side-effects. The results of MTT assays, a hemolysis test and the histological staining of organs indicated that the gelatin microcapsules showed excellent compatibility with the physiological environment. A possible mechanism is proposed for MW hyperthermia using gelatin microcapsules. We also used gelatin microcapsules capped with CdTe quantum dots for in vivo optical imaging. Our study suggests that these microcapsules may have potential applications in imaging-guided cancer treatment.

Topics: Animals; Biocompatible Materials; Cadmium Compounds; Cell Survival; Colloids; Erythrocyte Membrane; Erythrocytes; Female; Fluorescent Dyes; Gelatin; Hemolysis; Hep G2 Cells; Humans; Hyperthermia, Induced; L-Lactate Dehydrogenase; Mice; Mice, Inbred ICR; Microscopy, Electron, Scanning; Microwaves; Neoplasm Transplantation; Neoplasms; Optics and Photonics; Quantum Dots; Rabbits; Spectroscopy, Fourier Transform Infrared; Tellurium; Tissue Distribution

Currently, metallothioneins (MTs) are extensively investigated as the molecular biomarkers and the significant positive association of the MT amount was observed in tumorous versus healthy tissue of various types of malignant tumors, including head and neck cancer. Thus, we proposed a biosensor with fluorescence detection, comprising paramagnetic nanoparticles (nanomaghemite core with gold nanoparticles containing shell) for the magnetic separation of MT, based on affinity of its sulfhydryl groups toward gold. Biosensor was crafted from PDMS combined with technology of 3D printing and contained reservoir with volume of 50 μL linked to input (sample/detection components and washing/immunobuffer) and output (waste). For the immunolabeling of immobilized MT anti-MT antibodies conjugated to CdTe quantum dots through synthetic heptapeptide were employed. After optimization of fundamental conditions of the immunolabeling (120 min, 20°C, and 1250 rpm) we performed it on a surface of paramagnetic nanoparticles in the biosensor reservoir, with evaluation of fluorescence of quantum dots (λexc 400 nm, and λem 555 nm). The developed biosensor was applied for quantification of MT in cell lines derived from spinocellular carcinoma (cell line 122P-N) and fibroblasts (122P-F) and levels of the biomarker were found to be about 90 nM in tumor cells and 37 nM in fibroblasts. The proposed system is able to work with low volumes (< 100 μL), with low acquisition costs and high portability.

Topics: Biosensing Techniques; Cadmium Compounds; Cell Line, Tumor; Dimethylpolysiloxanes; Fluorescence; Gold; Humans; Magnetics; Metal Nanoparticles; Metallothionein; Neoplasms; Printing, Three-Dimensional; Quantum Dots; Tellurium

Nanomaterials capable of achieving tunable cargo release kinetics are of significance in a fundamental sense and various biological or medical applications. We report a competitive coordination system based on a novel tellurium-containing polymer and its ligand-regulated release manners. Tellurium was introduced to water-soluble polymers for the first time as drug delivery vehicles. The coordination chemistry between platinum and tellurium was designed to enable the load of platinum-based drugs. Through the competitive coordination of biomolecules, the drugs could be released in a controlled manner. Furthermore, the release kinetics could be modulated by the competitive ligands involved due to their different coordination ability. This tellurium-containing polymer may enrich the family of delivery systems and provide a new platform for future biomedical nanotechnologies.

Topics: Antineoplastic Agents; Cisplatin; Delayed-Action Preparations; Drug Delivery Systems; Hep G2 Cells; Humans; Ligands; Micelles; Neoplasms; Organoplatinum Compounds; Polymers; Pyridines; Tellurium

We report herein the facile surface-functionalization of one type of biocompatible, oligomeric nanoparticles 1-NPs with NIR-emitting CdTe/CdS QDs and folate for tumor-targeted imaging in vivo. The -NH2 and -SH groups of cysteine residues on the 1-NPs were utilized to covalently conjugate CdTe/CdS QDs and Mal-FA to prepare the hybrid nanoparticles 1-NPs-QDs-FA. As-prepared 1-NPs-QDs-FA showed NIR-fluorescence emission at 734 nm, selective uptake by FR-overexpressing tumor cells in vitro, and selective FR-overexpressing tumor-targeted imaging in vivo. This first example of oligomeric/inorganic hybrid nanoparticles provides people with new type of biomaterials for tumor-targeted imaging with high selectivity.

Topics: Animals; Cadmium Compounds; Diagnostic Imaging; Fluorescence; Folic Acid; Mice, Nude; Nanoparticles; Neoplasms; Optical Imaging; Organ Specificity; Quantum Dots; Spectroscopy, Near-Infrared; Sulfides; Tellurium

In this paper, we report microwave-assisted, one-stage synthesis of high-quality functionalized water-soluble cadmium telluride (CdTe) quantum dots (QDs). By selecting sodium tellurite as the Te source, cadmium chloride as the Cd source, mercaptosuccinic acid (MSA) as the capping agent, and a borate-acetic acid buffer solution with a pH range of 5-8, CdTe nanocrystals with four colors (blue to orange) were conveniently prepared at 100 °C under microwave irradiation in less than one hour (reaction time: 10-60 min). The influence of parameters such as the pH, Cd:Te molar ratio, and reaction time on the emission range and quantum yield percentage (QY%) was investigated. The structures and compositions of the prepared CdTe QDs were characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy, selective area electron diffraction, and X-ray powder diffraction experiments. The formation mechanism of the QDs is discussed in this paper. Furthermore, AS1141-aptamer-conjugated CdTe QDs in the U87MG glioblastoma cell line were assessed with a fluorescence microscope. The obtained results showed that the best conditions for obtaining a high QY of approximately 87% are a pH of 6, a Cd:Te molar ratio of 5:1, and a 30-min reaction time at 100 °C under microwave irradiation. The results showed that AS1141-aptamer-conjugated CdTe QDs could enter tumor cells efficiently. It could be concluded that a facile high-fluorescence-strength QD conjugated with a DNA aptamer, AS1411, which can recognize the extracellular matrix protein nucleolin, can specifically target U87MG human glioblastoma cells. The qualified AS1411-aptamer-conjugated QDs prepared in this study showed excellent capabilities as nanoprobes for cancer targeting and molecular imaging.

Topics: Aptamers, Nucleotide; Cadmium Compounds; Cell Line, Tumor; Fluorescence; Humans; Molecular Imaging; Molecular Probes; Molecular Structure; Neoplasms; Oligodeoxyribonucleotides; Quantum Dots; Staining and Labeling; Tellurium

Intraoperative lymph node mapping (LNM) is highly significant for many surgeries in patients with cancer. Many types of tracers are currently used, but the ideal method has not yet been identified. We aimed to identify a stable lymphatic drainage pathway in an animal model and compared the effects of quantum dots (QD), a new fluorescent tracer, with those of methylene blue in intraoperative LNM.. Indian ink (0.2 mL) was subcutaneously injected into the plantar metatarsal regions of six Sprague-Dawley rats. After 2 wk of incubation and subsequent dissection, the potentially stained LNs were examined pathologically to identify the lymphatic drainage pathway. After applying anesthesia, 0.1 mL methylene blue (2%) and QD (1 mg/mL) were injected into the plantar metatarsal regions of six rats for intraoperative LNM. The QD group was observed with a near-infrared imaging system, and the methylene blue group was directly observed. Drainages were recorded at 5, 10, 30, 60, and 120 min and at 1 d.. Two three-level drainage pathways, that is, a peripheral drainage (popliteal LNs, inguinal LNs, and axillary LNs) and a central drainage (popliteal lymph node [LN], iliac LN, and renal LN) pathways were identified. Both methylene blue and QD stained the sentinel lymph node (SLNs) quickly, but methylene blue was difficult to identify in the deep tissues and the LNs beyond the SLN. Furthermore, the blue-stained LNs remain dyed for only 2 h. In contrast, the QDs exhibited high target-to-background ratios in both the SLNs and the following LNs. Additionally, the fluorescence lasted from 5 min-1 d after injection.. An ideal lymphatic drainage model was found. QDs are excellent tracers for intraoperative LNM compared with methylene blue. Near infrared fluorescent imaging is a promising LNM method for clinical practice.

Topics: Animals; Cadmium; Fluorescent Dyes; Hindlimb; Intraoperative Period; Lymph Node Excision; Lymph Nodes; Male; Methylene Blue; Microscopy, Electron, Transmission; Neoplasms; Quantum Dots; Rats, Sprague-Dawley; Sentinel Lymph Node Biopsy; Spectroscopy, Near-Infrared; Tellurium

N-acetyl-L-cysteine (NAC) capped quantum dots (QDs) were synthesized by a hydrothermal method and coated with 2-amino-2-deoxy-D-glucose (DG), polyethylene glycol (PEG), and 9-D-arginine (9R). The optical properties, morphology and structure of 9R/DG-coated CdTe QDs were characterized by ultraviolet-visible spectrometry, fluorescence spectrum, Fourier transform infrared (FTIR), proton nuclear magnetic resonance (1H NMR), liquid chromatography-mass spectrometer (LC-MS), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transmission electron micrographs (TEM). Furthermore, the biocompatibility, tumor targeted ability and transmembrane action of 9R/DG-coated CdTe QDs were studied. Results indicated that 9R/DG-coated CdTe QDs was constructed successfully by ligand exchange. The 9R/DG-coated CdTe QDs with the size of 8-10 nm had good dispersity and the absorbance and fluorescence peaks of CdTe QDs after modification were red shifted from 480 nm to 510 nm and 627 nm to 659 nm, respectively. In addition, the CdTe QDs modified by PEG, DG and 9R displayed good biocompatibility, high targeted ability to the cancer cells with glucose transporter type 1 (GLUT1) receptor high expression and obvious transmembrane ability.

Topics: Acetylcysteine; Cadmium Compounds; Humans; Neoplasms; Polymers; Quantum Dots; Spectrophotometry, Ultraviolet; Tellurium

High quality and facile DNA functionalized quantum dots (QDs) as efficient fluorescence nanomaterials are of great significance for bioimaging both in vitro and in vivo applications. Herein, we offer a strategy to synthesize DNA-functionalized Zn(2+) doped CdTe QDs (DNA-QDs) through a facile one-pot hydrothermal route. DNA is directly attached to the surface of QDs. The as-prepared QDs exhibit small size (3.85 ± 0.53 nm), high quantum yield (up to 80.5%), and excellent photostability. In addition, the toxicity of QDs has dropped considerably because of the Zn-doping and the existence of DNA. Furthermore, DNA has been designed as an aptamer specific for mucin 1 overexpressed in many cancer cells including lung adenocarcinoma. The aptamer-functionalized Zn(2+) doped CdTe QDs (aptamer-QDs) have been successfully applied in active tumor-targeted imaging in vitro and in vivo. A universal design of DNA for synthesis of Zn(2+) doped CdTe QDs could be extended to other target sequences. Owing to the abilities of specific recognition and the simple synthesis route, the applications of QDs will potentially be extended to biosensing and bioimaging.

Topics: Animals; Aptamers, Nucleotide; Cadmium Compounds; Cell Line, Tumor; Chlorocebus aethiops; Humans; Mice, Nude; Neoplasms; Optical Imaging; Quantum Dots; SELEX Aptamer Technique; Tellurium; Vero Cells; X-Ray Diffraction; Zinc

Near-infrared (NIR, 700-900 nm) fluorescent quantum dots are highly promising as NIR bioprobes for high-resolution and high-sensitivity bioimaging applications. In this article, we present a class of NIR-emitting CdTe/CdS/ZnS core-shell-shell quantum dots (QDs), which are directly prepared in aqueous phase via a facile microwave synthesis. Significantly, the prepared NIR-emitting QDs possess excellent aqueous dispersibility, strong photoluminescence, favorable biocompatibility, robust storage-, chemical-, and photo-stability, and finely tunable emission in the NIR range (700-800 nm). The QDs are readily functionalized with antibodies for use in immunofluorescent bioimaging, yielding highly spectrally and spatially resolved emission for in vitro and in vivo imaging. In comparison to the large size of 15-30 nm of the conventional NIR QDs, the extremely small size (≈ 4.2 nm or 7.5 nm measured by TEM or DLS, respectively) of our QDs offers great opportunities for high-efficiency and high-sensitivity targeted imaging in cells and animals.

Topics: Animals; Cadmium Compounds; HeLa Cells; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasms; Optical Imaging; Quantum Dots; Solubility; Sulfides; Tellurium; Water; Zinc Compounds

To be able to label a gene and monitor its migration are key important approaches for the clinical application of cancer suicide gene therapy. Photonic nanomaterials are introduced in this work. One of the most promised suicide genes - herpes simplex virus thymidine kinase (HSV-TK) gene - is successfully linked with CdTe/CdS core/shell quantum dots (QDs) via EDC/NHS coupling method. From confocal microscopy it was demonstrated that plasmid TK intracellular trafficking can be effectively and distinctly traced via monitoring the luminescence of the QDs up to 96 h after transfection of QDs-TK conjugates into Hela cells. MTT results show that the QDs-TK conjugates have a high efficient cytotoxicity after adding GCV into Hela cells, whereas the QDs exert no detectable deleterious effects on the cellular processes. The apoptosis induced by QDs-TK conjugates with GCV is distinctly traced partly due to the strong luminescence of the QDs. Our results indicate that photonic nanomaterials, e.g. QDs, provide a tool for monitoring TK gene delivery and anti-cancer activity.

Topics: Antineoplastic Agents; Cadmium Compounds; Cell Death; Cell Shape; Cell Survival; Electrophoresis, Agar Gel; Ganciclovir; Genes, Transgenic, Suicide; Genetic Therapy; HeLa Cells; Humans; Neoplasms; Quantum Dots; Reproducibility of Results; Simplexvirus; Solubility; Sulfides; Tellurium; Thymidine Kinase; Transfection; Water

The synthesis of water-soluble near-infrared (NIR)-emitting quantum dots (QDs) has recently received extensive attention for non-invasive detection of biological information in living subjects. Highly fluorescent CdTeS alloyed QDs for biological application are introduced in this paper. QDs were synthesized by a hydrothermal method and coated with N-acetyl-l-cysteine (NAC) as both bioactive ligand and sulfur source for biocompatibility and biological stability. The optical properties, morphology and structure of CdTeS alloyed QDs were characterized. The in vitro and in vivo toxicity was intensively investigated. Furthermore, the dynamics and bio-distribution of CdTeS alloyed QDs on living mice were studied. To explore biomedical application, folate-polyethylene glycol (FA-PEG) was used to decorate the CdTeS alloyed QDs (FP-CdTeS QDs) for targeted imaging of tumors over-expressing the folate receptor (FR). The tumor targeting capability of FP-CdTeS QDs on tumor bearing nude mice was demonstrated. The results showed that the prepared CdTeS QDs have excellent optical properties and low toxicity, which makes them an ideal inorganic material for biomedical imaging. In addition, the folate-PEG conjugated NIR-QDs displayed good biocompatibility as well as excellent sensitivity and specificity for optical imaging of tumors which can extend the application of CdTeS QDs.

Topics: Acetylcysteine; Animals; Cadmium Compounds; Cell Line, Tumor; Cell Survival; Diagnostic Imaging; Female; Human Umbilical Vein Endothelial Cells; Humans; Kidney; Liver; Lung; Mice; Mice, Nude; Microscopy, Fluorescence; Neoplasm Transplantation; Neoplasms; Quantum Dots; Sulfides; Tellurium

We developed a novel chitosan-based luminescent/magnetic hybrid nanoparticles with folate-conjugated tetrapeptide composites (CLMNPs-tetrapeptide-FA) by conjugation in situ. First, chitosan, CdTe quantum dots (QDs), and superparamagnetic iron oxide were directly gelled into ternary hybrid nanogels. Subsequently, tetrapeptides (GFFG and LGPV) and folate were conjugated orderly into the hybrid nanoparticles. The morphology, composition, and properties of the as-prepared copolymers have also been characterized and determined using TEM, EDX, XRD, FTIR spectra, DLS, fluorescence spectroscopy, VSM, and fluorescence microscopy imaging studies. The size range of the end product CLMNPs-tetrapeptide-FA copolymers was from 150 to 190 nm under simulated physiological environment. In vivo, the experimental results of magnetic accumulation showed that the copolymers could be trapped in the tumor tissue under magnetic guidance. Under the present experimental conditions, the loading efficiencies of CPT were approximately 8.6 wt % for CLMNPs-GFFG-FA and 1.1 wt % for CLMNPs-LGPV-FA, respectively. The CPT cumulative release under dialysis condition mainly occurred for the first 28 h, and could reach 55% at pH 5.3 and 46% at pH 7.4 from CPT-loaded CLMNPs-GFFG-FA, and 69% at pH 5.3 and 57% at pH 7.4 from CPT-loaded CLMNPs-LGPV-FA within 28 h, respectively. The hemolysis percentages (<2%) and coagulation properties of blank and CPT-loaded copolymers were within the scope of safe values. Compared to free CPT, the CPT-loaded CLMNPs-tetrapeptide-FA copolymers showed specific targeting to A549 cells in vitro. More than 75% viability in L02 cells were seen in CLMNPs-GFFG-FA and CLMNPs-LGPV-FA copolymer concentration of 500 μg/mL, respectively. It was found that the two kinds of copolymers were transported into the A549 cells by a folate-receptor-mediated endocytosis mechanism. These results indicate that the multifunctional CLMNPs-tetrapeptide-FA copolymers possess a moderate CPT loading efficiency, low cytotoxicity, and favorable biocompatibility, and are promising candidates for tumor-targeted drug delivery.

Topics: Antineoplastic Agents, Phytogenic; Cadmium Compounds; Camptothecin; Cell Line, Tumor; Chitosan; Drug Delivery Systems; Folic Acid; Humans; Luminescence; Luminescent Agents; Magnetite Nanoparticles; Micelles; Neoplasms; Oligopeptides; Quantum Dots; Tellurium

CdTe/CdS core(small)/shell(thick) quantum dots (QDs) with tunable near-infrared fluorescence were directly synthesized in aqueous phase through a facile one-step strategy. The QDs possessed bright fluorescence, ultrasmall size, excellent photostability and good biocompatibility. Their applicability for biological imaging was demonstrated with the in vivo active tumor targeting of nude mice.

Topics: Animals; Cadmium Compounds; Fluorescent Dyes; Mice; Mice, Nude; Neoplasms; Quantum Dots; Sulfides; Tellurium

Based on a modular design, a novel ultrahigh-intensity nanoparticle probe was synthesized by orderly assembling supramolecular DNA/CdTe quantum dot nanowires and recognition DNA sequences on polystyrene microbeads. The probe was successfully applied to cancer cell imaging and visual detection of nucleic acids.

Topics: Cadmium Compounds; Cell Line, Tumor; Diagnostic Imaging; DNA; Humans; Molecular Probes; Nanoparticles; Nanowires; Neoplasms; Nucleic Acids; Particle Size; Polystyrenes; Quantum Dots; Surface Properties; Tellurium

A new synthesis protocol is described to obtain a CdTe decorated magnetite bifunctional nanosystem via dodecylamine (DDA) as cross linker. High resolution transmission electron microscopy (HRTEM), energy-dispersive x-ray spectroscopy (EDAX), vibrating sample magnetometry (VSM), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS) and fluorescence microscopy are used to characterize the constitution, size, composition and physical properties of these superparamagnetic-fluorescent nanoparticles. These CdTe decorated magnetite nanoparticles were then functionalized with anti-epidermal growth factor receptor (EGFR) antibody to specifically target cells expressing this receptor. The EGFR is a transmembrane glycoprotein and is expressed on tumor cells from different tissue origins including human leukemic cell line Molt-4 cells. The magnetite-CdTe composite nanosystem is shown to perform excellently for specific selection, magnetic separation and fluorescent detection of EGFR positive Molt-4 cells from a mixed population. Flow cytometry and confocal laser scanning microscopy results show that this composite nanosystem has great potential in antibody functionalized magnetic separation and imaging of cells using cell surface receptor antibody.

Topics: Cadmium Compounds; Cell Line, Tumor; Cell Survival; Contrast Media; ErbB Receptors; Humans; Immunomagnetic Separation; Luminescence; Magnetite Nanoparticles; Microscopy, Confocal; Neoplasms; Spectroscopy, Fourier Transform Infrared; Tellurium; Thermogravimetry; X-Ray Diffraction

This study examined the in vitro potential of bioconjugated quantum dots (QDs) as photosensitizers for photodynamic therapy (PDT). According to our previous approaches using photosensitizers, folic acid appears to be an optimal targeting ligand for selective delivery of attached therapeutic agents to cancer tissues. We synthesized hydrophilic near infrared emitting CdTe(S)-type QDs conjugated with folic acid using different spacers. Photodynamic efficiency of QDs conjugated or not with folic acid was evaluated on KB cells, acting as a positive control due to their overexpression of FR-α, and HT-29 cells lacking FR-α, as negative control. A design of experiments was suggested as a rational solution to evaluate the impacts of each experimental factor (QD type and concentration, light fluence and excitation wavelength, time of contact before irradiation and cell phenotype). We demonstrated that, for concentrations lower than 10 nM, QDs displayed practically no cytotoxic effect without light exposure for both cell lines. Whereas QDs at 2.1 nM displayed a weak photodynamic activity, a concentration of 8 nM significantly enhanced the photodynamic efficiency characterized by a light dose-dependent response. A statistically significant difference in photodynamic efficiency between KB and HT-29 cells was evidenced in the case of folic acid-conjugated QDs. Optimal conditions led to an enhanced photocytotoxicity response, allowing us to validate the ability of QDs to generate a photodynamic effect and of folic acid-conjugated QDs for targeted PDT.

Topics: Cadmium Compounds; Cell Line; Folate Receptor 1; Folic Acid; Humans; Neoplasms; Photochemotherapy; Photosensitizing Agents; Quantum Dots; Tellurium

Gelatine coating was previously shown to effectively reduce the cytotoxicity of CdTe Quantum Dots (QDs) which was a first step towards utilising them for biomedical applications. To be useful they also need to be target-specific which can be achieved by conjugating them with Folic Acid (FA).. The modification of QDs with FA via an original "one-pot" synthetic route was proved successful by a range of characterisation techniques including UV-visible absorption spectroscopy, Photoluminescence (PL) emission spectroscopy, fluorescence life-time measurements, Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS). The resulting nanocomposites were tested in Caco-2 cell cultures which over-express FA receptors. The presence of FA on the surface of QDs significantly improved the uptake by targeted cells.. The modification with folic acid enabled to achieve a significant cellular uptake and cytotoxicity towards a selected cancer cell lines (Caco-2) of gelatine-coated TGA-CdTe quantum dots, which demonstrated good potential for in vitro cancer diagnostics.

Topics: Caco-2 Cells; Cadmium Compounds; Folate Receptors, GPI-Anchored; Folic Acid; Gelatin; Humans; Microscopy, Confocal; Nanocomposites; Neoplasms; Quantum Dots; Tellurium

Topics: Cadmium Compounds; Humans; Nanotechnology; Neoplasms; Quantum Dots; Ribonuclease, Pancreatic; Tellurium

An autoradiography method revealed intratumoral inhomogeneity in various solid tumors. It is becoming increasingly important to estimate intratumoral inhomogeneity. However, with low spatial resolution and high scatter noise, it is difficult to detect intratumoral inhomogeneity in clinical settings. We developed a new PET system with CdTe semiconductor detectors to provide images with high spatial resolution and low scatter noise. Both phantom images and patients' images were analyzed to evaluate intratumoral inhomogeneity.. This study was performed with a cold spot phantom that had 6-mm-diameter cold sphenoid defects, a dual-cylinder phantom with an adjusted concentration of 1:2, and an "H"-shaped hot phantom. These were surrounded with water. Phantom images and (18)F-FDG PET images of patients with nasopharyngeal cancer were compared with conventional bismuth germanate PET images. Profile curves for the phantoms were measured as peak-to-valley ratios to define contrast. Intratumoral inhomogeneity and tumor edge sharpness were evaluated on the images of the patients.. The contrast obtained with the semiconductor PET scanner (1.53) was 28% higher than that obtained with the conventional scanner (1.20) for the 6-mm-diameter cold sphenoid phantom. The contrast obtained with the semiconductor PET scanner (1.43) was 27% higher than that obtained with the conventional scanner (1.13) for the dual-cylinder phantom. Similarly, the 2-mm cold region between 1-mm hot rods was identified only by the new PET scanner and not by the conventional scanner. The new PET scanner identified intratumoral inhomogeneity in more detail than the conventional scanner in 6 of 10 patients. The tumor edge was sharper on the images obtained with the new PET scanner than on those obtained with the conventional scanner.. These phantom and clinical studies suggested that this new PET scanner has the potential for better identification of intratumoral inhomogeneity, probably because of its high spatial resolution and low scatter noise.

Topics: Adult; Aged; Bismuth; Cadmium Compounds; Carcinoma, Squamous Cell; Female; Germanium; Glucose; Humans; Male; Nasopharyngeal Neoplasms; Neoplasms; Phantoms, Imaging; Positron-Emission Tomography; Semiconductors; Tellurium; Time Factors

We present and discuss results and features related to the synthesis of water-soluble semiconductor quantum dots and their application as fluorescent biomarkers in cancer diagnostics. We have prepared and applied different core-shell quantum dots, such as cadmium telluride-cadmium sulfide, CdTe-CdS, and cadmium sulfide-cadmium hydroxide, CdS/Cd(OH)(2), in living healthy and neoplastic cells and tissues samples. The CdS/Cd(OH)(2) quantum dots presented the best results, maintaining high levels of luminescence as well as high photostability in cells and tissues. Labeled tissues and cells were analyzed by their resulting fluorescence, via conventional fluorescence microscopy or via laser scanning confocal microscopy. The procedure presented in this work was shown to be efficient as a potential tool for fast and precise cancer diagnostics.

Topics: Cadmium Compounds; Cell Line, Tumor; Cells, Cultured; Cervix Uteri; Female; Fluorescence; Glioma; Humans; Microscopy, Confocal; Microscopy, Fluorescence; Nanotechnology; Neoplasms; Neuroglia; Quantum Dots; Sulfides; Tellurium; Uterine Cervical Dysplasia

The thioredoxins are small ubiquitous redox proteins with the conserved redox catalytic sequence-Trp-Cys-Gly-Pro-Cys-Lys, where the Cys residues undergo reversible NADPH dependent reduction by selenocysteine containing flavoprotein thioredoxin reductases. Thioredoxin expression is increased in several human primary cancers including lung, colon, cervix, liver, pancreatic, colorectal and squamous cell cancer. The thioredoxin/thioredoxin reductase pathway therefore provides an attractive target for cancer drug development. Organotellurium steroid, lipid, amino acid, nucleic base, and polyamine inhibitors were synthesized on the basis that they might be selectively or differentially incorporated into tumor cells. Some of the newly prepared classes of tellurium-based inhibitors (lipid-like compounds 3b and 3e, amino acid derivative 5b, nucleic base derivative 8b, and polyamine derivatives 14a and 14b) inhibited TrxR/Trx and cancer cell growth in culture with IC(50) values in the low micromolar range.

Topics: Cell Division; Humans; Magnetic Resonance Spectroscopy; Neoplasms; Tellurium; Thioredoxin-Disulfide Reductase

Attempts to detect tumors with intraoperative scintillation using tumor-binding radiopharmaceuticals have intensified recently. In some cases previously unknown lesions were found, but in most cases no additional lesions were detected. In this study the physical characteristics of three detector systems and their ability to detect tumors through accumulation of an 111In-labeled radiopharmaceutical were investigated. The first was a sodium iodide (NaI[TI]) detector; the second, a cesium iodide (CsI[TI]) detector; and the third, a cadmium telluride (CdTe) detector.. A body phantom and tumor phantoms (diameter 5-20 mm) made of water, agarose gel or epoxy with a density and attenuation coefficient similar to those of soft tissue were used to simulate a clinical situation. The activity concentration in the body phantom was based on reported values of 111In-octreotide in normal tissue in humans. The 111In activity concentration in the tumor phantoms varied from 3 to 80 times the 111In activity concentration in the body phantom. Data were processed to determine tumor detection levels.. The NaI(TI) detector showed the lowest values for full width at half maximum because this detector had the best collimation, leading to a high ratio between counts from tumor and counts from background, i.e., small tumors could be detected. Because of high efficiency, the CsI(TI) detector sometimes required a somewhat shorter acquisition time to produce a statistically significant difference between tumor phantom and background. For deep-lying tumors the NaI(TI) detector was superior, whereas the CdTe detector was best suited for superficial tumors with a high activity concentration in the underlying tissue.. At a maximum acquisition time of 30 s, almost all superficial tumors with a diameter of 10 mm or larger were detected if the ratio between the 111In concentration in the tumor and the 111In concentration in the background exceeded 3. However, in clinical situations, biologic variations in the uptake of 111In-octreotide in tumors and in normal tissue makes difficult the determination of a distinct detection level. For such clinical conditions, the NaI(TI) detector is the best choice because it has good resolution despite a lower efficiency. Documentation of detector characteristics is important so that clinicians can make an adequate device in relation to tumor location and receptor expression.

Topics: Cadmium Compounds; Cesium; Evaluation Studies as Topic; Gamma Rays; Humans; Indium Radioisotopes; Intraoperative Period; Iodides; Neoplasms; Octreotide; Pentetic Acid; Phantoms, Imaging; Radionuclide Imaging; Radiopharmaceuticals; Sodium Iodide; Tellurium

Topics: Cadmium; Cadmium Compounds; Gamma Rays; Humans; Myocardial Infarction; Neoplasms; Nuclear Medicine; Radiation Monitoring; Radiation, Ionizing; Radiography, Dental; Radioisotopes; Radiometry; Radionuclide Imaging; Scintillation Counting; Telemetry; Tellurium; Thrombosis

Topics: Animals; Aorta; Blood Glucose; Carcinogens; Cholesterol; Drinking; Female; Glycosuria; Growth; Lipids; Longevity; Male; Mortality; Neoplasms; Rats; Selenium; Tellurium; Water