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This study envisioned attaining the percipience of effective biohydrogen production from paper mill waste-activated sludge through low-temperature calcium peroxide-mediated bacterial pretreatment (TCP-BP). Floc dissociation with limited cell destruction was attained at a calcium peroxide dosage of 0.05 g/g suspended solids (SS) at 70 °C temperature. This TCP-BP method improves bacterial fragmentation, and very high SS solubilization was achieved at 42 h, with the solubilization and solid reduction of 18.6% and 14.1%, respectively. BP-only pretreatment shows lower solubilization efficiency of 9.4% than TCP-BP pretreatment due to the presence of flocs, which inhibit the enzymatic action during bacterial fragmentation. A biohydrogen test shows a high biohydrogen potential of 94.1 mL H2/gCOD for the TCP-BP sample, which is higher than that of the BP-only and control samples. According to the findings, low-temperature calcium peroxide-mediated bacterial fragmentation is validated to be an efficient process for sludge degradation and biohydrogen production.
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Bactérias , Esgotos , Temperatura , Esgotos/microbiologia , Bactérias/metabolismo , Peróxidos , Polímeros/metabolismoRESUMO
Cherenkov radiation (CR) derived from the decay of diagnostic and therapeutic radionuclides is currently being studied by the scientific community to determine if these emissions can be harnessed for cancer detection and therapy. While Cherenkov luminescence imaging (CLI) has been studied in the preclinical and clinical settings, Cherenkov radiation-induced cancer therapy (CRICT) is a relatively new area of research that harnesses the emitted photons to kill cancer cells through free radical generation and DNA damage. Nanoparticles seem well suited for developing a theranostic platform that would allow researchers to visualize therapy delivery and also generate the reactive oxygen species necessary to kill cancer cells. Herein, we report the preparation of an 89Zr-TiO2-MnO2 nanocomposite that incorporates transferrin onto the nanoparticle surface to enhance cancer cell growth inhibition. The incorporation of the positron emission tomography (PET) radioisotope 89Zr (half-life: 3.3 days) allowed for the detection of the nanoparticle using PET and for the creation of Cherenkov emissions that interacted with the nanoparticle surface to generate free radicals for therapy delivery. After preparation, these systems were observed to be stable in various media and provided excellent tumor growth control after being intratumorally injected into mice bearing CT-26 tumors. These results demonstrate that a therapeutically efficient CRICT platform can be generated using commercially available and affordable materials.
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Neoplasias , Radioisótopos , Camundongos , Animais , Zircônio , Medicina de Precisão , Compostos de Manganês/farmacologia , Óxidos , Tomografia por Emissão de Pósitrons , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neoplasias/radioterapiaRESUMO
Carotenoids are naturally occurring pigments that are widely distributed in algae, fungi, bacteria, and plants. Carotenoids play a significant role in the food, feed, cosmetic, nutraceutical, and pharmaceutical industries. These pigments are effectively considered as a health-promoting compounds, which are widely used in our daily diet to reduce the risk of chronic diseases such as cardiovascular diseases, cancer, acute lung injury, cataracts, neural disorders, etc. In this context, this review paper demonstrates the synthesis of carotenoids and their potential application in the food and pharmaceutical industries. However, the demand for carotenoid production is increasing overtime, and the extraction and production are expensive and technically challenging. The recent developments in carotenoid biosynthesis, and key challenges, bottlenecks, and future perspectives were also discussed to enhance the circular bioeconomy.
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Carotenoides , Fungos , Bactérias , Plantas , Suplementos NutricionaisRESUMO
Polyhydroxybutyrate (PHB) is a bio-based, biodegradable and biocompatible plastic that has the potential to replace petroleum-based plastics. Lignocellulosic biomass is a promising feedstock for industrial fermentation to produce bioproducts such as polyhydroxybutyrate (PHB). However, the pretreatment processes of lignocellulosic biomass lead to the generation of toxic byproducts, such as furfural, 5-HMF, vanillin, and acetate, which affect microbial growth and productivity. In this study, to reduce furfural toxicity during PHB production from lignocellulosic hydrolysates, we genetically engineered Cupriavidus necator NCIMB 11599, by inserting the nicotine amide salvage pathway genes pncB and nadE to increase the NAD(P)H pool. We found that the expression of pncB was the most effective in improving tolerance to inhibitors, cell growth, PHB production and sugar consumption rate. In addition, the engineered strain harboring pncB showed higher PHB production using lignocellulosic hydrolysates than the wild-type strain. Therefore, the application of NAD salvage pathway genes improves the tolerance of Cupriavidus necator to lignocellulosic-derived inhibitors and should be used to optimize PHB production.
Assuntos
Cupriavidus necator , Petróleo , Amidas/metabolismo , Cupriavidus necator/genética , Cupriavidus necator/metabolismo , Açúcares da Dieta/metabolismo , Açúcares da Dieta/farmacologia , Furaldeído/farmacologia , Inibidores do Crescimento/metabolismo , Inibidores do Crescimento/farmacologia , Hidroxibutiratos/metabolismo , Lignina , NAD/metabolismo , NAD/farmacologia , Nicotina/metabolismo , Nicotina/farmacologia , Nitrobenzenos , Petróleo/metabolismo , PlásticosRESUMO
64Cu and 67Cu are theragnostic pair radionuclides with promising application in the nuclear medicine. 64Cu is PET nuclide for the non-invasive diagnosis and 67Cu is beta emitter for therapy of various cancers. This study discusses optimization efforts in the production of these radioactive coppers carried out with 30 MeV cyclotron. Optimized conditions include target preparation, chemical separation, and quality control. The production routes of 64Cu and 67Cu were studied based on the nuclear reactions of 64Ni(p,n)64Cu and 70Zn(p,α)67Cu. The produced 64Cu and 67Cu have >99.9% of the radionuclidic purity. The yield at the end of bombardment (EOB) of 64Cu and 67Cu is 28.5 MBq/µAh and 67Cu is 0.58 MBq/µAh, respectively.
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This research work aimed about the enhanced bio-hydrogen production from marine macro algal biomass (Ulva reticulate) through surfactant induced microwave disintegration (SIMD). Microwave disintegration (MD) was performed by varying the power from 90 to 630 W and time from 0 to 40 min. The maximum chemical oxygen demand (COD) solubilisation of 27.9% was achieved for MD at the optimal power (40%). A surfactant, ammonium dodecyl sulphate (ADS) is introduced in optimal power of MD which enhanced the solubilisation to 34.2% at 0.0035 g ADS/g TS dosage. The combined SIMD pretreatment significantly reduce the treatment time and increases the COD solubilisation when compared to MD. Maximum hydrogen yield of 54.9 mL H2 /g COD was observed for SIMD than other samples. In energy analysis, it was identified that SIMD was energy efficient process compared to others since SIMD achieved energy ratio of 1.04 which is higher than MD (0.38).
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Alga Marinha , Biomassa , Micro-Ondas , Tensoativos/farmacologia , TermodinâmicaRESUMO
Radioactive isotopes are used as drugs or contrast agents in the medical field after being conjugated with chelates such as DOTA, NOTA, DTPA, TETA, CyDTA, TRITA, and DPDP. The N-terminal sequence of human serum albumin (HSA) is known as a metal binding site, such as for Co2+, Cu2+, and Ni2+. For this study, we designed and synthesized wAlb12 peptide from the N-terminal region of HSA, which can bind to cobalt, to develop a peptide-based chelate. The wAlb12 with a random coil structure tightly binds to the Co(II) ion. Moreover, the binding property of wAlb12 toward Co(II) was confirmed using various spectroscopic experiments. To identify the binding site of wAlb12, the analogs were synthesized by alanine scanning mutagenesis. Among them, H3A and Ac-wAlb12 did not bind to Co(II). The analysis of the binding regions confirmed that the His3 and α-amino group of the N-terminal region are important for Co(II) binding. The wAlb12 bound to Co(II) with Kd of 75 µM determined by isothermal titration calorimetry when analyzed by a single-site binding model. For the use of wAlb12 as a chelate in humans, its cytotoxicity and stability were investigated. Trypsin stability showed that the wAlb12 - Co(II) complex was more stable than wAlb12 alone. Furthermore, the cell viability analysis showed wAlb12 and wAlb12 + Co(II) to be non-toxic to the Raw 264.7 and HEK 293T cell lines. Therefore, a hot radioactive isotope such as cobalt-57 will have the same effect as a stable isotope cobalt. Accordingly, we expect wAlb12 to be used as a peptide chelate that binds with radioactive isotopes.
Assuntos
Quelantes/metabolismo , Cobalto/metabolismo , Peptídeos/metabolismo , Albumina Sérica Humana/metabolismo , Substituição de Aminoácidos , Animais , Sítios de Ligação , Sobrevivência Celular , Quelantes/química , Cromatografia Líquida de Alta Pressão , Cobalto/química , Humanos , Cinética , Camundongos , Peptídeos/química , Ligação Proteica , Estabilidade Proteica , Células RAW 264.7 , Análise Espectral , Relação Estrutura-AtividadeRESUMO
Nano-sized materials with properties that enable their internalization into target cells using passive targeting systems have been utilized with radioisotopes to track their pharmacokinetics in the body. Here, we report the incorporation of novel chelator-free Zr-89 using a hierarchical iron oxide nanocomposite (89Zr-IONC). Characterization revealed that it had a rice-shape with a mean width of 160 nm. The surface of the 89Zr-IONCs was coated by polyethyleneimine (PEI) and polyvinylpyrrolidone (PVP) to improve the cancer target efficacy. The biological behavior of the nanoparticles coated with the polymers differed significantly by the surface composition. Positron emission tomography measurements by the labeled Zr-89 effectively confirmed the cancer target capability and the fate of distribution in the body. We found that only PVP coated 89Zr-IONC reached the tumor region while non-coated and PEI coated 89Zr-IONC tended to be undesirably entirely cleared in the liver and spleen. The 89Zr-incorporated iron oxide nanocomposite is significantly stable for radiolabeling despite various surface modifications, allowing the potential carrier to specifically target cancer cells. The strategy of utilizing the biocompatible PEI and PVP surface coating system for negative charged nanoparticles such as iron oxide will afford enhanced biological application.
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Sistemas de Liberação de Medicamentos , Nanopartículas Metálicas/química , Radioisótopos , Zircônio , Adsorção , Animais , Antineoplásicos , Linhagem Celular Tumoral , Camundongos , Neoplasias Experimentais , Tomografia por Emissão de Pósitrons , Células RAW 264.7 , Propriedades de Superfície , Distribuição TecidualRESUMO
Notwithstanding many efforts to increase the efficiency of anaerobic digestion at low-temperature (winter) conditions, a cost-effective and efficient method is lacking. This study proposes a low-cost method of low-temperature (<35 °C) anaerobic digestion of wastewater, involving supplementation with granular activated carbon (GAC). Supplementation with GAC was found to reduce the lag time by 29.8% (from 15.1 to 10.6 days) and increase the maximum methane production rate by 23.4% (from 6.4 to 7.9 mL/day) at 25 °C. Network analysis demonstrated a strong co-occurrence of Syntrophobacteriales and hydrogenotrophic methanogens (Methanobacteriaceae; WSA2; Methanoregulaceae). GAC supplementation can drastically reduce the time required for organic matter decomposition and methane production, thereby increase the efficiency of wastewater treatment.
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Carvão Vegetal , Águas Residuárias , Anaerobiose , Reatores Biológicos , Suplementos Nutricionais , MetanoRESUMO
In this study, we investigated the tumor targeting effect in cancer cells using triphenylphosphonium (TPP) cations, which are accumulated by differences in membrane potential, and folic acid (FA), which is selectively bound to overexpressed receptors on various cancer cells. We used Food and Drug Administration (FDA)-approved silica nanoparticles (SNPs) as drug carriers, and SNPs conjugated with TPP and FA (STFs) samples were prepared by introducing different amounts of TPP and FA onto the nanoparticle surfaces. STF-1, 2, 3, 4 and 5 are named according to the combination ratio of TPP and FA on the particle surface. To confirm the tumor targeting effect, 89Zr (t1/2 = 3.3 days) was coordinated directly to the silanol group of SNP surfaces without chelators. It was shown that the radiochemical yield was 69% and radiochemical purity was >99%. In the cellular uptake evaluation, SNPs with the most TPP (SFT-5) and FA (SFT-1) attached indicated similar uptake tendencies for mouse colon cancer cells (CT-26). However, the results of the cell internalization assay and measurement of positron emission tomography (PET) images showed that SFT-5 had more affinity for the CT-26 tumor than other samples the TPP ratio of which was lower. Consequently, we confirmed that TPP ligands affect target cancer cells more than FA, which means that cell membrane potential is significantly effective for tumor targeting.
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Neoplasias do Colo/tratamento farmacológico , Ácido Fólico/química , Nanopartículas/administração & dosagem , Compostos Organofosforados/química , Radioisótopos/química , Compostos Radiofarmacêuticos/química , Dióxido de Silício/química , Zircônio/química , Animais , Cátions , Neoplasias do Colo/diagnóstico por imagem , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Tomografia por Emissão de PósitronsRESUMO
Prostate cancer is one of the most frequently found cancers in men worldwide. Prostate-specific membrane antigen (PSMA) is typically highly expressed in prostate cancer, and the Glu-Urea-Lys (GUL) structure has recently received considerable attention as a key unit of PSMA-targeting agents. Additionally, one of the common characteristics of many solid tumors, such as prostate cancer, is hypoxia. In this study, novel multifunctional PSMA inhibitors containing a PSMA-targeting moiety either with or without a hypoxia-sensitive moiety (18F-PEG3-ADIBOT-2NI-GUL and 18F-PEG3-ADIBOT-GUL, respectively; ADIBOT: azadibenzocyclooctatriazole, 2NI: 2-nitroimidazole) were designed and synthesized, and their feasibility as PET tracers for prostate cancer imaging studies was examined. The compounds labelled with 18F via the copper-free click reaction were stable in human serum and showed nanomolar binding affinities in in vitro PSMA binding assays. Micro-PET and biodistribution studies indicate that both 18F-labelled inhibitors successfully accumulated in prostate cancer regions, and 18F-PEG3-ADIBOT-2NI-GUL showed a 2-fold higher tumor-to-total non-target organ ratio than that of 18F-PEG3-ADIBOT-GUL, suggesting that the synergistic effects of the PSMA-targeting GUL moiety and the hypoxia-sensitive 2-nitroimidazole moiety can increase tumor uptake of the novel PET tracers in prostate cancer. These findings suggest that this novel multifunctional PET tracer with an 18F-labelled PSMA inhibitor and a 2-nitroimidazole moiety is a potent candidate to provide better diagnosis of prostate cancer via PET imaging studies.
Assuntos
Radioisótopos de Flúor/farmacocinética , Glutamato Carboxipeptidase II/antagonistas & inibidores , Hipóxia , Tomografia por Emissão de Pósitrons/métodos , Neoplasias da Próstata/patologia , Compostos Radiofarmacêuticos/farmacocinética , Animais , Antígenos de Superfície/metabolismo , Apoptose , Proliferação de Células , Radioisótopos de Flúor/química , Glutamato Carboxipeptidase II/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Modelos Moleculares , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/metabolismo , Compostos Radiofarmacêuticos/química , Distribuição Tecidual , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Imatinib (Gleevec) is a multiple tyrosine kinase inhibitor that decreases the activity of the fusion oncogene called BCR-ABL (breakpoint cluster region protein-Abelson murine leukemia viral oncogene homolog) and is clinically used for the treatment of chronic myelogenous leukemia and acute lymphocytic leukemia. Small molecule drugs, such as imatinib, can bind to several cellular proteins including the target proteins in the cells, inducing undesirable effects along with the effects against the disease. In this study, we report the synthetic optimization for 14 C-labeling and radiosynthesis of [14 C]imatinib to analyze binding with cellular proteins using accelerator mass spectroscopy. 14 C-labeling of imatinib was performed by the synthesis of 14 C-labeld 2-aminopyrimidine intermediate using [14 C]guanidine·HCl, which includes an in situ reduction of an inseparable byproduct for easy purification by HPLC, followed by a cross-coupling reaction with aryl bromide precursor. The radiosynthesis of [14 C]imatinib (specific activity, 631 MBq/mmol; radiochemical purity, 99.6%) was achieved in six steps with a total chemical yield of 29.2%.
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Radioisótopos de Carbono/química , Mesilato de Imatinib/síntese química , Inibidores de Proteínas Quinases/síntese química , Proteínas Tirosina Quinases/antagonistas & inibidores , Animais , Humanos , Mesilato de Imatinib/química , Marcação por Isótopo , Inibidores de Proteínas Quinases/química , RadioquímicaRESUMO
Biomimetic nanoparticles (NPs) have been actively studied for their biological compatibility due to its distinguished abilities viz. long-term circulation, low toxicity, ease for surface modification, and its ability to avoid phagocytosis of NPs by macrophages. Coating the NPs with a variety of cell membranes bearing the immune control proteins increases drug efficacy while complementing the intrinsic advantages of the NPs. In this study, efforts were made to introduce oxophilic radiometal 89Zr with hollow mesoporous silica nanospheres (HMSNs) having abundant silanol groups and were bioengineered with red blood cell membrane (Rm) having cluster of differentiation 47 (CD47) protein to evaluate its long-term in vivo behavior. We were successful in demonstrating the increased in vivo stability of synthesized Rm-camouflaged, 89Zr-labelled HMSNs with the markedly reduced 89Zr release. Rm camouflaged 89Zr-HMSNs effectively accumulated in the tumor by avoiding phagocytosis of macrophages. In addition, re-injecting the Rm isolated using the blood of the same animal helped to overcome the immune barrier. This novel strategy can be applied extensively to identify the long-term in vivo behavior of nano-drugs while enhancing their biocompatibility.
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Materiais Biomiméticos , Membrana Eritrocítica/metabolismo , Nanosferas , Fagocitose , Dióxido de Silício , Zircônio , Animais , Bioengenharia/métodos , Linhagem Celular Tumoral , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Nanosferas/ultraestrutura , RadioisótoposRESUMO
Heat-shock protein 90 (HSP90) is a molecular chaperone that activates oncogenic transformation in several solid tumors, including lung and breast cancers. Ganetespib, a most promising candidate among several HSP90 inhibitors under clinical trials, has entered Phase III clinical trials for cancer therapy. Despite numerous evidences validating HSP90 as a target of anticancer, there are few studies on PET agents targeting oncogenic HSP90. In this study, we synthesized and biologically evaluated a novel 18F-labeled 5-resorcinolic triazolone derivative (1, [18F]PTP-Ganetespib) based on ganetespib. [18F]PTP-Ganetespib was labeled by click chemistry of Ganetespib-PEG-Alkyne (10) and [18F]PEG-N3 (11) with 37.3⯱â¯5.11% of radiochemical yield and 99.7⯱â¯0.09% of radiochemical purity. [18F]PTP-Ganetespib showed proper LogP (0.96⯱â¯0.06) and good stability in human serum over 97% for 2â¯h. [18F]PTP-Ganetespib showed high uptakes in breast cancer cells containing triple negative breast cancer (TNBC) MDA-MB-231 and Her2-negative MCF-7 cells, which are target breast cancer cell lines of HSP90 inhibitor, ganetespib, as an anticancer. Blocking of HSP90 by the pretreatment of ganetespib exhibited significantly decreased accumulation of [18F]PTP-Ganetespib in MDA-MB-231 and MCF-7 cells, indicating the specific binding of [18F]PTP-Ganetespib to MDA-MB-231 and MCF-7 cells with high HSP90 expression. In the biodistribution and microPET imaging studies, the initial uptake into tumor was weaker than in other thoracic and abdominal organs, but [18F]PTP-Ganetespib was retained relatively longer in the tumor than other organs. The uptake of [18F]PTP-Ganetespib in tumors was not sufficient for further development as a tumor-specific PET imaging agent by itself, but this preliminary PET imaging study of [18F]PTP-Ganetespib can be basis for developing new PET imaging agents based on HSP90 inhibitor, ganetespib.
Assuntos
Proteínas de Choque Térmico HSP90/metabolismo , Compostos Radiofarmacêuticos/síntese química , Triazóis/química , Animais , Sítios de Ligação , Linhagem Celular Tumoral , Química Click , Cristalografia por Raios X , Estabilidade de Medicamentos , Radioisótopos de Flúor/química , Proteínas de Choque Térmico HSP90/química , Humanos , Camundongos , Camundongos Nus , Simulação de Acoplamento Molecular , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos/sangue , Compostos Radiofarmacêuticos/metabolismo , Distribuição Tecidual , Transplante Heterólogo , Triazóis/sangue , Triazóis/metabolismoRESUMO
BACKGROUND: Removal of the plate following Le Fort I osteotomy and BSSO (bilateral sagittal split osteotomy) is a common procedure. However, patients who undergo plate removal experience intense pain and discomfort. This study investigated the half-maximal effective concentration (Ce50 ) of remifentanil in the prevention of plate removal pain under sedation using dexmedetomidine. METHODS: The study evaluated 18 patients, between 18 and 35 years of age, scheduled for elective surgery. Remifentanil infusion was initiated after sedation using dexmedetomidine, and started at a dose of 1.5 ng/mL on the first patient via target-controlled infusion (TCI). Patients received a loading dose of 1.0 µg/kg dexmedetomidine over 10 min, followed by a maintenance dose of 0.7 µg/kg/h. When the surgeon removed the plate, the patient Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score was observed. RESULTS: The Ce of remifentanil ranged from 0.9 to 2.1 ng/mL for the patients evaluated. The estimated effect-site concentrations of remifentanil associated with a 50% and 95% probability of reaching MOAA/S score of 3 were 1.28 and 2.51 ng/mL, respectively. CONCLUSIONS: Plate removal of maxilla can be successfully performed without any pain or adverse effects by using the optimal remifentanil effect-site concentration (Ce50 , 1.28 ng/mL; Ce95 , 2.51 ng/mL) combined with sedation using dexmedetomidine.
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Carbonic anhydrase IX is overexpressed in many solid tumors including hypoxic tumors and is a potential target for cancer therapy and diagnosis. Reported imaging agents targeting CA-IX are successful mostly in clear cell renal carcinoma as SKRC-52 and no candidate was approved yet in clinical trials for imaging of CA-IX. To validate CA-IX as a valid target for imaging of hypoxic tumor, we designed and synthesized novel [18F]-PET tracer (1) based on acetazolamide which is one of the well-known CA-IX inhibitors and performed imaging study in CA-IX expressing hypoxic tumor model as 4T1 and HT-29 in vivo models other than SKRC-52. [18F]-acetazolamide (1) was found to be insufficient for the specific accumulation in CA-IX expressing tumor. This study might be useful to understand in vivo behavior of acetazolamide PET tracer and can contribute to the development of successful PET imaging agents targeting CA-IX in future. Additional study is needed to understand the mechanism of poor targeting of CA-IX, as if CA-IX is not reliable as a sole target for imaging of CA-IX expressing hypoxic solid tumors.
Assuntos
Acetazolamida/química , Anidrase Carbônica IX/análise , Inibidores da Anidrase Carbônica/química , Carcinoma de Células Renais/enzimologia , Neoplasias Renais/enzimologia , Tomografia por Emissão de Pósitrons , Acetazolamida/síntese química , Acetazolamida/farmacocinética , Animais , Anidrase Carbônica IX/biossíntese , Anidrase Carbônica IX/metabolismo , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/farmacocinética , Carcinoma de Células Renais/diagnóstico , Radioisótopos de Flúor , Humanos , Neoplasias Renais/diagnóstico , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias Experimentais/diagnóstico , Neoplasias Experimentais/enzimologia , Distribuição TecidualRESUMO
INTRODUCTION: Positron emission tomography (PET) tracers has the potential to revolutionize cancer imaging and diagnosis. PET tracers offer non-invasive quantitative imaging in biotechnology and biomedical applications, but it requires radioisotopes as radioactive imaging tracers or radiopharmaceuticals. METHOD: This paper reports the synthesis of 18F-nGO-PEG by covalently functionalizing PEG with nano-graphene oxide, and its excellent stability in physiological solutions. Using a green synthesis route, nGO is then functionalized with a biocompatible PEG polymer to acquire high stability in PBS and DMEM. RESULTS AND DISCUSSION: The radiochemical safety of 18F-nGO-PEG was measured by a reactive oxygen species and cell viability test. The biodistribution of 18F-nGO-PEG could be observed easily by PET, which suggested the significantly high sensitivity tumor uptake of 18F-nGO-PEG and in a tumor bearing CT-26 mouse compared to the control. 18F-nGO-PEG was applied successfully as an efficient radiotracer or drug agent in vivo using PET imaging. This article is expected to assist many researchers in the fabrication of 18F-labeled graphene-based bio-conjugates with high reproducibility for applications in the biomedicine field.
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Grafite/química , Nanocompostos/química , Compostos Radiofarmacêuticos/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Radioisótopos de Flúor/química , Radioisótopos de Flúor/farmacocinética , Grafite/farmacologia , Química Verde , Humanos , Células MCF-7 , Camundongos Nus , Óxidos/química , Polietilenoglicóis/química , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/farmacocinética , Espécies Reativas de Oxigênio/metabolismo , Reprodutibilidade dos Testes , Distribuição Tecidual , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The 68 Ga is a positron-emitting radionuclide that can be combined with bifunctional chelating agents and bioactive substances for use as positron-emission tomography (PET) diagnostic agents. The HBED-CC is an acyclic chelating agent that is rapidly labeled with 68 Ga under mild conditions. To target cancer cells, bioactive substances can be conjugated to the carboxyl terminus of HBED-CC. Because folic acid strongly binds to folate receptors that are overexpressed on the surfaces of many types of cancer cells, it was coupled with HBED-CC through a small polyethylene glycol-based linker (EDBE) to generate an active, receptor-selective targeting system. The HBED-CC-EDBE-folate (HCEF) precursor was readily labeled with 68 Ga in 5 minutes at room temperature (98% radiochemical yield; 99% radiochemical purity after isolation). In cellular uptake tests, higher uptakes of 68 Ga-HCEF were observed for the CT26 and KB cell lines (which express folate receptors) than for the A549 cell line (which does not). Finally, in vivo micro-PET measurements over 2 hours of binding in BALB/c mice into which CT26 tumors had been transplanted showed the selective accumulation of 68 Ga-HCEF in the folate receptor-expressing CT26 tumors. These results confirmed the potential of 68 Ga-HCEF as a PET diagnostic agent for tumors that express folate receptors.
Assuntos
Ácido Edético/análogos & derivados , Radioisótopos de Gálio/química , Neoplasias Experimentais/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/síntese química , Animais , Linhagem Celular Tumoral , Ácido Edético/química , Ácido Fólico/análogos & derivados , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Polietilenoglicóis/química , Compostos Radiofarmacêuticos/farmacocinética , Distribuição TecidualRESUMO
68Ga-labeled capsaicin using a DOTA (1,4,7,10-tetraazocyclododecane-N,N',Nâ³,N'â³-tetraacetic acid) derivative [68Ga-SCN-Benzyl(Bn)-DOTA-capsaicin] was studied for the diagnosis of breast cancers, such as MCF-7 and SK-BR-3. The standard compound, 69Ga-SCN-Bn-DOTA-capsaicin, was also prepared and characterized by spectroscopic analysis. The binding affinity of 68Ga-SCN-Bn-DOTA-capsaicin was evaluated by using breast cancer cell lines (MCF-7, SK-BR-3) and colon cancer cell (CT-26); the biodistribution was carried out by using MCF-7-bearing nude mice, after which the positron emission tomography (PET) images were obtained at different time intervals (15-120 minutes). 68Ga-SCN-Bn-DOTA-capsaicin showed a cellular uptake of 0.93% Injected Dose (ID) after 30 minutes of incubation, whereas 68Ga-SCN-Bn-DOTA showed a lower uptake of 0.25% ID. The tumor-to-blood ID/g% ratios increased and were found to be 0.49, 0.22, and 0.77 for 15, 30, and 60 minutes, respectively. The small-animal PET study showed that the uptake of 68Ga-SCN-Bn-DOTA-capsaicin was higher in the tumor regions even at 30 minutes after injection. These results suggest that 68Ga-SCN-Bn-DOTA-capsaicin is a potential targeting agent for PET imaging of MCF-7.