scholarly journals Preclinical Evaluation of Radiolabeled Peptides for PET Imaging of Glioblastoma Multiforme

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2496 ◽  
Author(s):  
Zbynek Novy ◽  
Jana Stepankova ◽  
Michaela Hola ◽  
Dominika Flasarova ◽  
Miroslav Popper ◽  
...  
Keyword(s):  
Glioblastoma Multiforme ◽  
Tumor Imaging ◽  
Ex Vivo ◽  
Tumor Model ◽  
Rgd Peptides ◽  
Radiolabeled Peptides ◽  
Biodistribution Studies ◽  
Target Organs

In this study, we have compared four 68Ga-labeled peptides (three Arg-Gly-Asp (RGD) peptides and substance-P) with two 18F-tracers clinically approved for tumor imaging. We have studied in vitro and in vivo characteristics of selected radiolabeled tracers in a glioblastoma multiforme tumor model. The in vitro part of the study was mainly focused on the evaluation of radiotracers stability under various conditions. We have also determined in vivo stability of studied 68Ga-radiotracers by analysis of murine urine collected at various time points after injection. The in vivo behavior of tested 68Ga-peptides was evaluated through ex vivo biodistribution studies and PET/CT imaging. The obtained data were compared with clinically used 18F-tracers. 68Ga-RGD peptides showed better imaging properties compared to 18F-tracers, i.e., higher tumor/background ratios and no accumulation in non-target organs except for excretory organs.

68Ga-labeled HBED-CC Variant of uPAR Targeting Peptide AE105 Compared with 68Ga-NODAGA-AE105

2019 ◽  
Vol 18 (9) ◽  
pp. 1289-1294 ◽  
Author(s):  
Kusum Vats ◽  
Rohit Sharma ◽  
Haladhar D. Sarma ◽  
Drishty Satpati ◽  
Ashutosh Dash
Keyword(s):  
Solid Phase ◽  
Evaluation Studies ◽  
Radiochemical Yield ◽  
In Vivo Evaluation ◽  
Peptide Conjugates ◽  
Biodistribution Studies ◽  
Target Organs ◽  
U87mg Tumor

Aims: The urokinase Plasminogen Activator Receptors (uPAR) over-expressed on tumor cells and their invasive microenvironment are clinically significant molecular targets for cancer research. uPARexpressing cancerous lesions can be suitably identified and their progression can be monitored with radiolabeled uPAR targeted imaging probes. Hence this study aimed at preparing and evaluating two 68Ga-labeled AE105 peptide conjugates, 68Ga-NODAGA-AE105 and 68Ga-HBED-CC-AE105 as uPAR PET-probes. Method: The peptide conjugates, HBED-CC-AE105-NH2 and NODAGA-AE105-NH2 were manually synthesized by standard Fmoc solid phase strategy and subsequently radiolabeled with 68Ga eluted from a commercial 68Ge/68Ga generator. In vitro cell studies for the two radiotracers were performed with uPAR positive U87MG cells. Biodistribution studies were carried out in mouse xenografts with the subcutaneously induced U87MG tumor. Results: The two radiotracers, 68Ga-NODAGA-AE105 and 68Ga-HBED-CC-AE105 that were prepared in >95% radiochemical yield and >96% radiochemical purity, exhibited excellent in vitro stability. In vivo evaluation studies revealed higher uptake of 68Ga-HBED-CC-AE105 in U87MG tumor as compared to 68Ga-NODAGAAE105; however, increased lipophilicity of 68Ga-HBED-CC-AE105 resulted in slower clearance from blood and other non-target organs. The uPAR specificity of the two radiotracers was ascertained by significant (p<0.05) reduction in the tumor uptake with a co-injected blocking dose of unlabeled AE-105 peptide. Conclusion: Amongst the two radiotracers studied, the neutral 68Ga-NODAGA-AE105 with more hydrophilic chelator exhibited faster clearance from non-target organs. The conjugation of HBED-CC chelator (less hydrophilic) resulted in negatively charged 68Ga-HBED-CC-AE105 which was observed to have high retention in blood that decreased target to non-target ratios.

scholarly journals Effect of ethanol and cocaine on [11C]MPC-6827 uptake in SH-SY5Y cells

2021 ◽  
Author(s):  
Naresh Damuka ◽  
Miranda Orr ◽  
Paul W. Czoty ◽  
Jeffrey L. Weiner ◽  
Thomas J. Martin ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Ex Vivo ◽  
Neuroblastoma Cells ◽  
Proper Function ◽  
Brain Functions ◽  
Biodistribution Studies ◽  
Positron Emission ◽  
Vitro Binding

AbstractMicrotubules (MTs) are structural units in the cytoskeleton. In brain cells they are responsible for axonal transport, information processing, and signaling mechanisms. Proper function of these processes is critical for healthy brain functions. Alcohol and substance use disorders (AUD/SUDs) affects the function and organization of MTs in the brain, making them a potential neuroimaging marker to study the resulting impairment of overall neurobehavioral and cognitive processes. Our lab reported the first brain-penetrant MT-tracking Positron Emission Tomography (PET) ligand [11C]MPC-6827 and demonstrated its in vivo utility in rodents and non-human primates. To further explore the in vivo imaging potential of [11C]MPC-6827, we need to investigate its mechanism of action. Here, we report preliminary in vitro binding results in SH-SY5Y neuroblastoma cells exposed to ethanol (EtOH) or cocaine in combination with multiple agents that alter MT stability. EtOH and cocaine treatments increased MT stability and decreased free tubulin monomers. Our initial cell-binding assay demonstrated that [11C]MPC-6827 may have high affinity to free/unbound tubulin units. Consistent with this mechanism of action, we observed lower [11C]MPC-6827 uptake in SH-SY5Y cells after EtOH and cocaine treatments (e.g., fewer free tubulin units). We are currently performing in vivo PET imaging and ex vivo biodistribution studies in rodent and nonhuman primate models of AUD and SUDs and Alzheimer's disease.

Nanocarriers with Gentamicin to Treat Intracellular Pathogens

2006 ◽  
Vol 6 (9) ◽  
pp. 3296-3302 ◽  
Author(s):  
C. Lecaroz ◽  
C. Gamazo ◽  
M. J. Blanco-Prieto
Keyword(s):  
Macrophage Activation ◽  
Polymeric Nanoparticles ◽  
Current Treatment ◽  
Delivery Systems ◽  
Oxygen Intermediates ◽  
Water Solvent ◽  
Biodistribution Studies ◽  
Target Organs

Brucellosis is a worldwide zoonosis caused by different species of the genus Brucella. The intracellular localisation of this pathogen, particularly in macrophages, renders treatment difficult since most antibiotics known to be efficient in vitro do not actively pass through cellular membranes. As alternative to current treatment, polymeric drug delivery systems containing gentamicin have been developed. These particulate carriers target the drug into the mononuclear-phagocytic system, where the pathogen resides that will allow intracellular accumulation of the antibiotic after particle degradation. Besides, particle uptake may induce macrophage activation, increasing the production of reactive oxygen intermediates, involved in host defense against the intracellular pathogen. The aim of the present work was to study the suitability of polymeric nanoparticles for gentamicin entrapment in view to treat brucellosis. Different poly(lactide-co-glycolide) PLGA polymers were used to formulate the nanoparticles containing gentamicin by a water-oil-water solvent evaporation method. Furthermore, in vitro macrophage activation upon nanoparticles phagocytosis and in vivo distribution of the nanocarriers in the target organs for Brucella (liver and spleen) were also studied. The nanoparticle sizes were below 350 nm, the gentamicin encapsulation efficiency depended on the polymer type used for their preparation and the in vitro release of the antibiotic exhibited a continuos pattern (PLGA 502H). PLGA 502H nanoparticles were the most suitable due to the highest entrapment and the most sustained release. The nanoparticles were successfully phagocyted by a J774 murine monocytes cell line and biodistribution studies in mice after intravenous administration of the delivery systems revealed that the particles reached the target organs of Brucella (liver and spleen). All together, these results indicate that the nanocarriers described in this work may be suitable as gentamicin delivery system to control brucellosis.

Dendritic cells modified to express CD40 ligand elicit therapeutic immunity against preexisting murine tumors

Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Toshiaki Kikuchi ◽  
Malcolm A. S. Moore ◽  
Ronald G. Crystal
Keyword(s):  
Dendritic Cells ◽  
Cytotoxic T Lymphocyte ◽  
Tumor Regression ◽  
Ex Vivo ◽  
Tumor Model ◽  
Adenovirus Vector ◽  
Cd40 Ligand ◽  
Murine Tumors

CD40 ligand (CD40L) is essential for the initiation of antigen-specific T-cell responses. This study is based on the hypothesis that dendritic cells (DCs) genetically modified ex vivo to express CD40L will enhance in vivo presentation of tumor antigen to the cellular immune system with consequent induction of antitumor immunity to suppress tumor growth. To examine this concept, subcutaneous murine tumors were injected with bone marrow-derived DCs that had been modified in vitro with an adenovirus (Ad) vector expressing murine CD40L (AdmCD40L). In B16 (H-2b, melanoma) and CT26 (H-2d, colon cancer) murine models, intratumoral injection of 2 × 106 AdmCD40L-modified DCs (CD40L-DCs) to established (day 8) subcutaneous tumors resulted in sustained tumor regression and survival advantage. This antitumor effect was sustained when the number of CD40L-DCs were reduced 10-fold to 2 × 105. Analysis of spleens from CD40L-DC–treated animals demonstrated that CD40L-DCs injected into the subcutaneous CT26 flank tumors migrated to the spleen, resulting in activation of immune-relevant processes. Consistent with this concept, intratumoral administration of CD40L-DCs elicited tumor-specific cytotoxic T-lymphocyte responses, and the transfer of spleen cells from CD40L-DC–treated mice efficiently protected naive mice against a subsequent tumor challenge. In a distant 2-tumor model of metastatic disease, an untreated B16 tumor in the right flank regressed in parallel with a left B16 tumor treated with direct injection of CD40L-DCs. These results support the concept that genetic modification of DCs with a recombinant CD40L adenovirus vector may be a useful strategy for directly activating DCs for cancer immunotherapy.

scholarly journals Anti-Tumoral and Anti-Angiogenic Effects of Low-Diluted Phenacetinum on Melanoma

2021 ◽  
Vol 11 ◽  
Author(s):  
Camille Fuselier ◽  
Sandrine Quemener ◽  
Eleonore Dufay ◽  
Camille Bour ◽  
Camille Boulagnon-Rombi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Side Effects ◽  
Ex Vivo ◽  
Tumor Model ◽  
Primary Cutaneous Melanoma ◽  
Relieve Pain ◽  
Melanoma Treatment ◽  
Vertical Growth Phase

Melanoma is the most aggressive form of skin cancer and the most rapidly expanding cancer in terms of worldwide incidence. If primary cutaneous melanoma is mostly treated with a curative wide local excision, malignant melanoma has a poor prognosis and needs other therapeutic approaches. Angiogenesis is a normal physiological process essential in growth and development, but it also plays a crucial role in crossing from benign to advanced state in cancer. In melanoma progression, angiogenesis is widely involved during the vertical growth phase. Currently, no anti-angiogenic agents are efficient on their own, and combination of treatments will probably be the key to success. In the past, phenacetin was used as an analgesic to relieve pain, causing side effects at large dose and tumor-inducing in humans and animals. By contrast, Phenacetinum low-dilution is often used in skin febrile exanthema, patches profusely scattered on limbs, headache, or flushed face without side effects. Herein are described the in vitro, in vivo, and ex vivo anti-angiogenic and anti-tumoral potentials of Phenacetinum low-dilution in a B16F1 tumor model and endothelial cells. We demonstrate that low-diluted Phenacetinum inhibits in vivo tumor growth and tumor vascularization and thus increases the survival time of B16F1 melanoma induced-C57BL/6 mice. Moreover, Phenacetinum modulates the lung metastasis in a B16F10 induced model. Ex vivo and in vitro, we evidence that low-diluted Phenacetinum inhibits the migration and the recruitment of endothelial cells and leads to an imbalance in the pro-tumoral macrophages and to a structural malformation of the vascular network. All together these results demonstrate highly hopeful anti-tumoral, anti-metastatic, and anti-angiogenic effects of Phenacetinum low-dilution on melanoma. Continued studies are needed to preclinically validate Phenacetinum low-dilution as a complementary or therapeutic strategy for melanoma treatment.

scholarly journals [68Ga]Ga-DFO-c(RGDyK): Synthesis and Evaluation of Its Potential for Tumor Imaging in Mice

2021 ◽  
Vol 22 (14) ◽  
pp. 7391
Author(s):  
Sona Krajcovicova ◽  
Andrea Daniskova ◽  
Katerina Bendova ◽  
Zbynek Novy ◽  
Miroslav Soural ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Tumor Imaging ◽  
Ex Vivo ◽  
Cell Uptake ◽  
Αvβ3 Integrin ◽  
In Vitro Characterization ◽  
Positron Emission ◽  
Gallium 68

Angiogenesis has a pivotal role in tumor growth and the metastatic process. Molecular imaging was shown to be useful for imaging of tumor-induced angiogenesis. A great variety of radiolabeled peptides have been developed to target αvβ3 integrin, a target structure involved in the tumor-induced angiogenic process. The presented study aimed to synthesize deferoxamine (DFO)-based c(RGD) peptide conjugate for radiolabeling with gallium-68 and perform its basic preclinical characterization including testing of its tumor-imaging potential. DFO-c(RGDyK) was labeled with gallium-68 with high radiochemical purity. In vitro characterization including stability, partition coefficient, protein binding determination, tumor cell uptake assays, and ex vivo biodistribution as well as PET/CT imaging was performed. [68Ga]Ga-DFO-c(RGDyK) showed hydrophilic properties, high stability in PBS and human serum, and specific uptake in U-87 MG and M21 tumor cell lines in vitro and in vivo. We have shown here that [68Ga]Ga-DFO-c(RGDyK) can be used for αvβ3 integrin targeting, allowing imaging of tumor-induced angiogenesis by positron emission tomography.

scholarly journals Dissolving Microneedles for Intradermal Vaccination against Shigellosis

Vaccines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 159 ◽  
Author(s):  
Pastor ◽  
Larrañeta ◽  
Erhard ◽  
Quincooces ◽  
Peñuelas ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Ex Vivo ◽  
Membrane Vesicle ◽  
Outer Membrane Vesicles ◽  
Ex Vivo Model ◽  
Intradermal Vaccination ◽  
Dissolving Microneedles ◽  
Biodistribution Studies

Intradermal (ID) immunization is of increasing interest due to the easy accessibility and excellent immunogenic properties of the skin. Among ID immunization methods, dissolving microneedles (MNs) have appeared as an alternative to traditional hypodermic immunization, offering many advantages, such as being an easily administered method, with no need for health personnel, painless, and avoiding the use of needles and sharp wastage. In this study, an affordable and easy-to-produce MNs method was developed based on aqueous blends of 30% w/w poly (methyl vinyl ether-co-maleic anhydride). As an antigen model, a subunit vaccine candidate based on outer membrane vesicles from Shigella flexneri was used. Both unloaded and antigen-loaded MNs were synthetized and characterized. The MNs were successfully validated in an in vitro Parafilm M® skin model and in a pig skin ex vivo model. Biodistribution studies were performed in BALB/c mice using 99mTcO4- radiolabeled samples. Results indicated that the vesicle vaccine was successfully released from the MNs and targeted gastrointestinal tract after 6 h post-administration. In vivo immunization and protection studies were performed in BALB/c mice. Mice were intradermally immunized through ear skin with one single dose of 200 g antigenic complex, eliciting the production of specific systemic IgG and mucosal IgA. Moreover, MNs were able to protect mice from an experimental infection with 1×106 CFU/mouse of S. flexneri four weeks after immunization. This work demonstrates for the first time the potential of outer membrane vesicle-loaded dissolving MNs for ID vaccination against enteropathogens like Shigella.

scholarly journals Radiosynthesis and Evaluation of Talazoparib and its Derivatives as PARP-1-Targeting Agents

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 565
Author(s):  
Dong Zhou ◽  
Huaping Chen ◽  
Cedric Mpoy ◽  
Sadia Afrin ◽  
Buck E. Rogers ◽  
...  
Keyword(s):  
Tumor Model ◽  
Repair Process ◽  
In Vivo Evaluation ◽  
Competitive Binding Assay ◽  
Targeted Radiotherapy ◽  
Molar Activity ◽  
Biodistribution Studies ◽  
Parp 1

Poly (ADP-ribose) polymerase-1 (PARP-1) is a critical enzyme in the DNA repair process and the target of several FDA-approved inhibitors. Several of these inhibitors have been radiolabeled for non-invasive imaging of PARP-1 expression or targeted radiotherapy of PARP-1 expressing tumors. In particular, derivatives of olaparib and rucaparib, which have reduced trapping potency by PARP-1 compared to talazoparib, have been radiolabeled for these purposes. Here, we report the first radiosynthesis of [18F]talazoparib and its in vitro and in vivo evaluation. Talazoparib (3a”) and its bromo- or iodo-derivatives were synthesized as racemic mixtures (3a, 3b and 3c), and these compounds exhibit high affinity to PARP-1 (Ki for talazoparib (3a”): 0.65 ± 0.07 nM; 3a: 2.37 ± 0.56 nM; 3b: 1.92 ± 0.41 nM; 3c: 1.73 ± 0.43 nM; known PARP-1 inhibitor Olaparib: 1.87 ± 0.10 nM; non-PARP-1 compound Raclopride: >20,000 nM) in a competitive binding assay using a tritium-labeled PARP-1 radioligand [3H]WC-DZ for screening. [18F]Talazoparib (3a”) was radiosynthesized via a multiple-step procedure with good radiochemical and chiral purities (98%) and high molar activity (28 GBq/μmol). The preliminary biodistribution studies in the murine PC-3 tumor model showed that [18F]talazoparib had a good level of tumor uptake that persisted for over 8 h (3.78 ± 0.55 %ID/gram at 4 h and 4.52 ± 0.32 %ID/gram at 8 h). These studies show the potential for the bromo- and iodo- derivatives for PARP-1 targeted radiotherapy studies using therapeutic radionuclides.

scholarly journals FSMP-09. FORMATE PROMOTES CANCER CELL INVASION AND METASTASIS VIA CALCIUM SIGNALING

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. i18-i18
Author(s):  
Catherine Delbrouck ◽  
Vitaly I Pozdeev ◽  
Anais Oudin ◽  
Kamil Grzyb ◽  
Laura Neises ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Ex Vivo ◽  
Tumor Model ◽  
Underlying Mechanism ◽  
Tumor Escape ◽  
Proliferating Cells ◽  
Nucleotide Synthesis ◽  
Formate Production

Abstract Serine catabolism via the folate cycle provides formate that is essential for nucleotide synthesis in proliferating cells. In addition to this canonical function to support biomass production in anabolic cells, we have recently demonstrated in vitro and in vivo that formate production in cancer cells is often in excess of the anabolic demand. This excess formate production is characterized by formate overflow and thus, net formate excretion into the tumor microenvironment. Interestingly, we observe increased rates of formate overflow upon different chemical perturbations that induce growth arrest. Thus, stressed cancer cells that encounter growth restriction such as upon chemotherapy, are often characterized by increased formate release rates. We demonstrated that such high formate levels in the extracellular space promote invasion of glioblastoma cells. Using ex vivo brain slice cultures and an orthotopic brain tumor model, we demonstrate that silencing MTHFD1L, the essential enzyme to enable formate overflow, results in decreased invasiveness of the tumor. Embarking from this observation, we investigated the underlying mechanism and now provide evidence that the formate-dependent increase of cell motility is mediated by an activation of Ca2+ signaling. Activation of Ca2+ signaling triggers integrin and matrix metallopeptidase (MMP) responses enabling the invasion process. Targeting either the Ca2+ response or MMP release can suppress the formate dependent increase in invasion. Finally, we tested the effect of formate also in context of breast cancer where we were able to recapitulate our observation of increased invasiveness and, in this case, formate also promoted the metastatic potential. We conclude that excreted formate might serve as a cellular stress signal that represents a promotive trigger to support tumor escape mechanisms.

scholarly journals Liposomal Chitosan-N-Acetyl Cysteine Nanoparticle for In-Vitro/In-Vivo Near Infrared Fluorescent (NIR) Imaging

2019 ◽  
Author(s):  
Piyush Kumar ◽  
Timothy Van Treuren ◽  
Amalendu Ranjan ◽  
Jamboor K Vishwanatha
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
Tumor Imaging ◽  
Ex Vivo ◽  
Breast Cancer Cell Lines ◽  
Nir Imaging ◽  
Negative Surface ◽  
Acetyl Cysteine

<p>In this work, we studied the effect of chitosan conjugated N-acetyl cysteine (CHT-NAC) coating on liposomal (DMPC:14 lysoPG: DSPE-2000-NH2) nanoparticles as a vehicle to cross the blood-brain barrier. The size of lipo-NP and Lipo-CHT-NAC NP were sub 50 nm with negative surface charge consistent with its use in an intravenous application. In vitro near infrared (NIR) imaging showed good cellular uptake in two triple-negative breast cancer cell lines (MDA-MB-231 and brain metastatic MDA-MB-831). Live (4-120 h) and ex-vivo near-infrared imaging at 24 h in nude mice showed the extended circulation of CHT-NAC Lipo-NP. These results demonstrated that Lipo-CHT-NAC NP could be used for metastatic brain tumor imaging.</p>

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