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[IEEE 2018 International Conference on Intelligent Informatics and Biomedical Sciences (ICIIBMS) - Bangkok (2018.10.21-2018.10.24)] 2018 International Conference on Intelligent Informatics and Biomedical Sciences (ICIIBMS) - A Novel Tumor Imaging Agent, Tc-99m and Fluorescence Labeled Gastrin-Releasing Peptide Analogues
摘要： Statement of the Problem: A variety of imaging probes have been developed for different molecular targets. The gastrin-releasing peptide (GRP) analogues (GRP, GRP18-27 and GRP21-27) were investigated vigorously as a targeting peptide for tumor, however, the cancer targeting abilities of these GRP analogues had not been compared head-to-head. Direct comparison of characteristics of these analogues will provide a useful information for the design of molecular imaging agent associated with GRP and an insight within the mechanism of tumor targeting using GRP analogues. Approach: In the present study, we developed Tc-99m and fluorescence (carboxytetramethylrhodamine, TAMRA) labeled GRP analogues containing three different peptides (TAMRA-GHEG-ECG-GRP, TAMRA-GHEG-ECG-GRP18-27 and TAMRA-GHEG-ECG-GRP21-27) to target the tumor cells and compared the tumor targeting abilities using in vitro and in vivo experiments. Peptides were synthesized using Fmoc solid-phase peptide synthesis. Radiolabeling of peptides with Tc-99m was done using ligand exchange via tartrate. Binding affinity and in vitro cellular uptake studies were performed. Gamma camera imaging study was performed in murine models with PC-3 tumors. The average counts per pixel within the ROIs were measured and target-to-non-target ratios were calculated. Results: After radiolabeling procedures with Tc-99m, Tc-99m labeled peptides were prepared in high yield (>96%). Tc-99m TAMRA-GHEG-ECG-GRP (Kd = 7.9 ± 2.7 nM) showed highest binding affinity for PC-3 tumor cells and Tc-99m TAMRA-GHEG-ECG-GRP18-27 (Kd = 12.6 ± 3.6 nM) showed relatively low binding affinity. Confocal microscopy images of PC-3 cells incubated with TAMRA-GHEG-ECG-GRP and TAMRA-GHEG-ECG-GRP21-27 showed strong fluorescence in the cytoplasm. Gamma camera imaging revealed substantial uptake of Tc-99m TAMRA-GHEG-ECG-GRP21-27 in tumors. Conclusion: We developed three Tc-99m and TAMRA labeled GRP analogues as a molecular imaging agent for targeting tumor. In vitro studies demonstrated substantial binding affinity and cellular uptake of TAMRA-GHEG-ECG-GRP and TAMRA-GHEG-ECG-GRP21-27. In contrast, in vivo gamma imaging study revealed that only Tc-99m TAMRA-GHEG-ECG-GRP21-27 was significantly accumulated in the tumor tissue. Taken together, the present study suggest that 7-mer peptide, GRP21-27 is the best surrogate as a targeting ligand for tumor imaging.
关键词： Gastrin-releasing peptide,Bombesin,Tc-99m,TAMRA,Multimodal imaging
更新于2025-09-23 15:22:29
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Photoactive Functional Soft Materials (Preparation, Properties, and Applications) || Photoresponsive Soft Materials Based on Reversible Proton Transfer
摘要： Proton transfer is one of the most fundamental processes in nature and numerous chemical, material, and biological processes are driven by proton transfer. For example, biological systems use proton gradient as an energy form to synthesize ATP for their biological functions; many organic reactions are catalyzed by Bronsted acids; and many materials have pH‐sensitive properties. Proton transfer is also involved in different aspects of polymer science relative to preparation, property, and processing. For example, cationic polymerizations can be initiated by proton transfer from a strong acid to a monomer. It has been reported that many polymers are sensitive to the pH (proton concentration) of the environment, and their properties including mechanical, geometrical, electric, optical, and magnetic properties, change with pH due to proton transfer between the polymers and the environment. Polymers with acid‐labile bonds have been studied for drug delivery; and photoinduced cationic polymerization using photoacid‐generators (PAGs) has been applied to photolithography.
关键词： Proton transfer,photoacid,fragrant‐releasing polymers,photoresponsive nanoparticles,photochromic materials,photoresponsive polymers,reversible
更新于2025-09-23 15:21:01
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Plasma charging effect on the nanoparticles releasing from the cavitation bubble to the solution during nanosecond Pulsed Laser Ablation in Liquid
摘要： The laser induced plasma during the nanosecond Pulsed Laser Ablation in Liquid (PLAL) plays a crucial role in the nanoparticles (NPs) formation and charging. It was demonstrated that during the plasma phase evolution, once the NPs are formed, they are charged with the excess of plasma electrons. Immediately after the plasma phase extinguishes, the NPs will be released in the induced vapor bubble, generated by the fast energy exchanges between the plasma and the liquid. The excess of charge in the NPs preserves them from the agglomeration during the bubble evolution and can induces an electrostatic pressure able to eject the particles outside the cavitation bubble. In this work, the plasma charging effect on the particle releasing in solution, during the bubble evolution, has been investigated. Temporal evolution of laser induced bubble on silver target immersed in water has been measured with the shadowgraph technique. Then, starting from the experimental bubble radius evolution, the releasing of the NPs from the cavitation bubble to the liquid has been modeled by comparing the electrostatic pressure of the charged NPs cloud and the pressure of the cavitation bubble. The following discussion proposes a new insight of the mechanism of NPs releasing in solution.
关键词： Laser Ablation Synthesis in Solution (LASIS),Cavitation bubble,NPs releasing,Pulsed Laser Ablation in Liquid (PLAL),NP formation
更新于2025-09-23 15:19:57
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Prerequisites and prospects for the development of novel systems based on the Keplerate type polyoxomolybdates for the controlled release of drugs and fluorescent molecules
摘要： Synthetic approaches were proposed to the development of hybrid organic—inorganic systems based on giant Keplerate polyoxometalates (POM Мо132), biocompatible polymers, and fluorescent molecules. A concept was formulated for the production of new systems for the prolonged release of drugs bearing a constant or temporary (protonated group) positive charge and fluorescent labels for tissue staining during electrophoretic introduction. In particular, a possibility of covalent functionalization of the POM Мо132 surface by the organosilicon molecules (aminopropyltrimethoxysilane) was shown. A promising procedure of the synthesis of NHS-esters of rhodamine B for the subsequent inclusion into the hybrid system was developed. The kinetic studies of POM destruction in an aqueous medium were carried out. The influence of association of rhodamine B with Мо132 on the character of fluorescence was studied.
关键词： organosilicon compounds,prolonged release,releasing,drug delivery systems,fluorescence,polyoxomolybdates
更新于2025-09-23 15:19:57
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NIR‐Laser‐Controlled Hydrogen‐Releasing PdH Nanohydride for Synergistic Hydrogen‐Photothermal Antibacterial and Wound‐Healing Therapies
摘要： For decades, hydrogen (H2) gas has been recognized as an excellent antioxidant molecule that holds promise in treating many diseases like Alzheimer’s, stroke, cancer, and so on. For the first time, active hydrogen is demonstrated to be highly efficient in antibacterial, antibiofilm, and wound-healing applications, in particular when used in combination with the photothermal effect. As a proof of concept, a biocompatible hydrogen-releasing PdH nanohydride, displaying on-demand controlled active hydrogen release property under near-infrared laser irradiation, is fabricated by incorporating H2 into Pd nanocubes. The obtained PdH nanohydride combines both merits of bioactive hydrogen and photothermal effect of Pd, exhibiting excellent in vitro and in vivo antibacterial activities due to its synergistic hydrogen-photothermal therapeutic effect. Interestingly, combinational hydrogen-photothermal treatment is also proved to be an excellent therapeutic methodology in healing rats’ wound with serious bacterial infection. Moreover, an in-depth antibacterial mechanism study reveals that two potential pathways are involved in the synergistic hydrogen-photothermal antibacterial effect. One is to upregulate bacterial metabolism relevant genes like dmpI, narJ, and nark, which subsequently encode more expression of oxidative metabolic enzymes to generate substantial reactive oxygen species to induce DNA damage and another is to cause severe bacterial membrane damage to release intracellular compounds like DNA.
关键词： wound healing,hydrogen releasing materials,synergistic hydrogen-photothermal therapy,antibacterial mechanism,antibacterial activity
更新于2025-09-11 14:15:04
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Positron Emission Tomography (PET) Imaging of Prostate Cancer with a Gastrin Releasing Peptide Receptor Antagonist - from Mice to Men
摘要： Ex vivo studies have shown that the gastrin releasing peptide receptor (GRPr) is overexpressed on almost all primary prostate cancers, making it a promising target for prostate cancer imaging and targeted radiotherapy. Methods: Biodistribution, dosimetry and tumor uptake of the GRPr antagonist 64Cu-CB-TE2A-AR06 [(64Cu-4,11-bis(carboxymethyl)-1,4,8,11-tetraazabicyclo(6.6.2)hexadecane)-PEG4-D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-LeuNH2] were studied by PET/CT in four patients with newly diagnosed prostate cancer (T1c-T2b, Gleason 6-7). Results: No adverse events were observed after injection of 64Cu-CB-TE2A-AR06. Three of four tumors were visualized with high contrast [tumor-to-prostate ratio > 4 at 4 hours (h) post injection (p.i.)], one small tumor (T1c, < 5% tumor on biopsy specimens) showed moderate contrast (tumor-to-prostate ratio at 4 h: 1.9). Radioactivity was cleared by the kidneys and only the pancreas demonstrated significant accumulation of radioactivity, which rapidly decreased over time. Conclusion: 64Cu-CB-TE2A-AR06 shows very favorable characteristics for imaging prostate cancer. Future studies evaluating 64Cu-CB-TE2A-AR06 PET/CT for prostate cancer detection, staging, active surveillance, and radiation treatment planning are necessary.
关键词： Gastrin releasing peptide receptor,bombesin,prostate cancer,PET/CT
更新于2025-09-04 15:30:14