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1.
Bioconjug Chem ; 35(5): 633-637, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38656148

RESUMO

Zirconium-89 is the most widely used radioisotope for immunoPET because its physical half-life (78.2 h) suits the one of antibodies. Desferrioxamine B (DFO) is the standard chelator for the complexation of zirconium(IV), and its bifunctional version, containing a phenylisothiocyanate function, is the most commonly used for the conjugation of DFO to proteins. However, preliminary results have shown that the thiourea link obtained from the conjugation of isothiocyanate and lysines is sensitive to the ionizing radiation generated by the radioisotope, leading to the rupture of the link and the release of the chelator/radiometal complex. This radiolysis phenomenon could produce nonspecific signal and prevent the detection of bone metastasis, as free zirconium accumulates into the bones. The aim of this work was to study the stability of a selection of conjugation linkers in 89Zr-labeled immunoconjugates. We have synthesized several DFO-based bifunctional chelators appended with an isothiocyanate moiety, a bicyclononyne, or a squaramate ester. Two antibodies (trastuzumab and rituximab) were conjugated and radiolabeled with zirconium-89. The effect of increasing activities of zirconium-89 on the integrity of the bioconjugate bearing thiourea links was evaluated as well as the impact of the presence of a radioprotectant. The stability of the radiolabeled antibodies was studied over 7 days in PBS and human plasma. Radioconjugates' integrity was evaluated using iTLC and size-exclusion chromatography. This study shows that the nature of the linker between the chelator and biomolecule can have a strong impact on the stability of the 89Zr-labeled conjugates, as well as on the aggregation of the conjugates.


Assuntos
Imunoconjugados , Isotiocianatos , Radioisótopos , Zircônio , Zircônio/química , Imunoconjugados/química , Isotiocianatos/química , Radioisótopos/química , Quelantes/química , Humanos , Desferroxamina/química
2.
Bioconjug Chem ; 34(11): 2144-2153, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37931154

RESUMO

For the past two decades, the emerging role of the endothelin (ET) axis in cancer has been extensively investigated, and its involvement in several mechanisms described as "hallmarks of cancer" has clearly highlighted its potential as a therapeutic target. Despite the growing interest in finding effective anticancer drugs, no breakthrough treatment has successfully made its way to the market. Recently, our team reported the development of a new immuno-positron emission tomography probe targeting the ET A receptor (ETA, one of the ET receptors) that allows the successful detection of ETA+ glioblastoma, paving the way for the elaboration of novel antibody-based strategies. In this study, we describe the synthesis of two PET/NIRF (positron emission tomography/near-infrared fluorescence) dually functionalized imaging agents, directed against ETA or ETB, that could be used to detect ET+ tumors and select patients that will be eligible for fluorescence-guided surgery. Both imaging modalities were brought together using a highly versatile tetrazine platform bearing the IRDye800CW fluorophore and desferrioxamine for 89Zr chelation. This so-called monomolecular multimodal imaging probe was then "clicked", via an inverse-electron-demand Diels-Alder reaction, to antibodies conjugated site-specifically with a trans-cyclooctene group. This approach has led to homogeneous and well-defined constructs that retained their high affinity and high specificity for their respective target, as shown by flow cytometry and NIRF in vivo imaging experiments in nude mice bearing CHO-ETA and CHO-ETB tumors. Ultimately, these bimodal immunoconjugates could be used to improve the outcomes of patients with ET+ tumors.


Assuntos
Glioblastoma , Imunoconjugados , Animais , Camundongos , Humanos , Receptores de Endotelina , Camundongos Nus , Tomografia por Emissão de Pósitrons/métodos , Imagem Óptica/métodos , Linhagem Celular Tumoral
3.
Eur J Nucl Med Mol Imaging ; 50(11): 3192-3201, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37280303

RESUMO

BACKGROUND: The resistance of glioblastoma stem cells (GSCs) to treatment is one of the causes of glioblastoma (GBM) recurrence. Endothelin A receptor (ETA) overexpression in GSCs constitutes an attractive biomarker for targeting this cell subpopulation, as illustrated by several clinical trials evaluating the therapeutic efficacy of endothelin receptor antagonists against GBM. In this context, we have designed an immunoPET radioligand combining the chimeric antibody targeting ETA, chimeric-Rendomab A63 (xiRA63), with 89Zr isotope and evaluated the abilities of xiRA63 and its Fab (ThioFab-xiRA63) to detect ETA+ tumors in a mouse model xenografted orthotopically with patient-derived Gli7 GSCs. RESULTS: Radioligands were intravenously injected and imaged over time by µPET-CT imaging. Tissue biodistribution and pharmacokinetic parameters were analyzed, highlighting the ability of [89Zr]Zr-xiRA63 to pass across the brain tumor barrier and achieve better tumor uptake than [89Zr]Zr-ThioFab-xiRA63. CONCLUSIONS: This study shows the high potential of [89Zr]Zr-xiRA63 in specifically targeting ETA+ tumors, thus raising the possibility of detecting and treating ETA+ GSCs, which could improve the management of GBM patients.


Assuntos
Glioblastoma , Animais , Camundongos , Humanos , Glioblastoma/diagnóstico por imagem , Receptor de Endotelina A , Tomografia por Emissão de Pósitrons/métodos , Distribuição Tecidual , Anticorpos , Células-Tronco , Linhagem Celular Tumoral , Zircônio
4.
Mol Pharm ; 20(7): 3613-3622, 2023 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-37307296

RESUMO

Noninvasive imaging of idiopathic pulmonary fibrosis (IPF) remains a challenge. The aim of this study was to develop an antibody-based radiotracer targeting Lysyl Oxidase-like 2 (LOXL2), an enzyme involved in the fibrogenesis process, for SPECT/CT imaging of pulmonary fibrosis. The bifunctional chelator DOTAGA-PEG4-NH2 was chemoenzymatically conjugated to the murine antibody AB0023 using microbial transglutaminase, resulting in a degree of labeling (number of chelators per antibody) of 2.3. Biolayer interferometry confirmed that the binding affinity of DOTAGA-AB0023 to LOXL2 was preserved with a dissociation constant of 2.45 ± 0.04 nM. DOTAGA-AB0023 was then labeled with 111In and in vivo experiments were carried out in a mice model of progressive pulmonary fibrosis induced by intratracheal administration of bleomycin. [111In]In-DOTAGA-AB0023 was injected in three groups of mice (control, fibrotic, and treated with nintedanib). SPECT/CT images were recorded over 4 days p.i. and an ex vivo biodistribution study was performed by gamma counting. A significant accumulation of the tracer in the lungs of the fibrotic mice was observed at D18 post-bleomycin. Interestingly, the tracer uptake was found selectively upregulated in fibrotic lesions observed on CT scans. Images of mice that received the antifibrotic drug nintedanib from D8 up to D18 showed a decrease in [111In]In-DOTAGA-AB0023 lung uptake associated with a decrease in pulmonary fibrosis measured by CT scan. In conclusion, we report the first radioimmunotracer targeting the protein LOXL2 for nuclear imaging of IPF. The tracer showed promising results in a preclinical model of bleomycin-induced pulmonary fibrosis, with high lung uptake in fibrotic areas, and accounted for the antifibrotic activity of nintedanib.


Assuntos
Fibrose Pulmonar Idiopática , Proteína-Lisina 6-Oxidase , Animais , Camundongos , Proteína-Lisina 6-Oxidase/metabolismo , Distribuição Tecidual , Fibrose Pulmonar Idiopática/induzido quimicamente , Fibrose Pulmonar Idiopática/diagnóstico por imagem , Pulmão/metabolismo , Fibrose , Tomografia Computadorizada de Emissão de Fóton Único , Bleomicina , Anticorpos/metabolismo
5.
J Prosthet Dent ; 129(2): 363.e1-363.e7, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36577570

RESUMO

STATEMENT OF PROBLEM: Optimal implant positioning is essential to achieving predictable results. Computer-guided surgery has been reported to be an accurate technique for implant placement in healed sites, but the accuracy of guided techniques for immediate implant placement into fresh sockets is still unclear. PURPOSE: The purpose of this experimental randomized split-mouth study in pig jaws was to determine the accuracy of partially and fully guided surgical techniques for immediate implant placement into fresh sockets and to compare 2 different methods of implant position deviations analysis. MATERIAL AND METHODS: Twenty implants were installed in 10 pig jaws using 2 different techniques: partially guided (n=10) and fully guided (n=10). Cone beam computed tomography and digital scanning were performed before and after the surgical procedure to plan the virtual implant position and fabricate the surgical guide, as well as to determine implant position deviations. Two methods were used to evaluate implant deviations: tomographic and digital scanning. The Shapiro-Wilk test of normality was used. Deviation comparisons were carried out by using paired t tests (α=.05), and intraclass correlation coefficient (ICC) was computed to assess the agreement between the 2 methods of implant deviation analysis. RESULTS: In the tomographic analysis, the partially guided technique resulted in significantly higher global apical and lateral coronal deviations (2.25 ±0.59 mm; 0.96 ±0.55 mm) than fully guided (1.52 ±0.89 mm; 0.75 ±0.52 mm) (P<.01 and P<.05, respectively). The analysis performed using digital scanning showed significantly higher angular, global apical, and lateral apical deviations in the partially guided (6 ±3.28 degrees; 2.49 ±1.03 mm; 2.16 ±1.07 mm) technique than in the fully guided (3.32 ±1.84 degrees; 1.5 ±0.58 mm; 0.98 ±0.67 mm) (P<.05). An ICC of 0.522 between the 2 methods of implant deviation analysis was obtained. CONCLUSIONS: The partially guided technique was less accurate than the fully guided technique for immediate implant placement into fresh sockets. A moderate concordance was observed between cone beam computed tomography and digital scanning analyses, suggesting that more studies are required to validate and to define the most reliable method of measuring implant deviation.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Animais , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endóssea/métodos , Imageamento Tridimensional , Maxila/cirurgia , Boca , Cirurgia Assistida por Computador/métodos , Suínos
6.
Artigo em Inglês | MEDLINE | ID: mdl-37329397

RESUMO

The purpose of this study was to analyze the volume and area of sphenoid sinuses of Brazilian individuals' cone-beam computed tomography (CBCT) images using the beta version of the DDS-Pro™ 2.14.2_2022 software (DPP Systems, Czestochowa, Poland), to assess a potential correlation to sex, age, skin color, and nutritional status, and to evaluate differences between the right and left sides. Three-dimensional volume and area measurements were made with the software using CBCT images of 113 living Brazilian individuals of both sexes (67 females and 46 males). TEM, rTEM, and R were used to assess the reproducibility of inter- and intra-examiner measurements. The measurement means were estimated with 95% confidence intervals according to sex and age group. There were no significant differences between the left and right sides for both volume and area and between the sexes and black and white individuals. Volume and area were significantly higher in 18 years or older (p < 0.05) and in individuals with normal body mass index (BMI) (p < 0.05). The obtained results do not allow indicating the use of sphenoid sinuses volume and area measurements to estimate sexual dimorphism, and the same occurred for skin color. However, such measures can help to estimate age. Further studies are suggested with a larger sample, especially for the nutritional status variable.

7.
Bioconjug Chem ; 33(3): 530-540, 2022 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-35230093

RESUMO

Because positron emission tomography (PET) and optical imaging are very complementary, the combination of these two imaging modalities is very enticing in the oncology field. Such bimodal imaging generally relies on imaging agents bearing two different imaging reporters. In the bioconjugation field, this is mainly performed by successive random conjugations of the two reporters on the protein vector, but these random conjugations can alter the vector properties. In this study, we aimed at abrogating the heterogeneity of the bimodal imaging immunoconjugate and mitigating the impact of multiple random conjugations. A trivalent platform bearing a DFO chelator for 89Zr labeling, a NIR fluorophore, IRDye800CW, and a bioconjugation handle was synthesized. This bimodal probe was site-specifically grafted to trastuzumab via glycan engineering. This new bimodal immunoconjugate was then investigated in terms of radiochemistry, in vitro and in vivo, and compared to the clinically relevant random equivalent. In vitro and in vivo, our strategy provides several improvements over the current clinical standard. The combination of site-specific conjugation with the monomolecular platform reduced the heterogeneity of the final immunoconjugate, improved the resistance of the fluorophore toward radiobleaching, and reduced the nonspecific uptake in the spleen and liver compared to the standard random immunoconjugate. To conclude, the strategy developed is very promising for the synthesis of better defined dual-labeled immunoconjugates, although there is still room for improvement. Importantly, this conjugation strategy is highly modular and could be used for the synthesis of a wide range of dual-labeled immunoconjugates.


Assuntos
Imunoconjugados , Neoplasias , Linhagem Celular Tumoral , Corantes Fluorescentes/química , Humanos , Imunoconjugados/química , Tomografia por Emissão de Pósitrons/métodos , Radioisótopos/química , Distribuição Tecidual , Zircônio/química
8.
Ann Diagn Pathol ; 57: 151888, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35121238

RESUMO

Adrenal cysts are rare, benign, and usually asymptomatic, being detected as an incidental finding on imaging methods. Adrenal Cysts of Lymphatic Origin (ACLO) and Adrenal Lymphangiomas (AL) are types of endothelial cyst and are the most prevalent subtype in this series. This study aims to present a single institutional experience of these rare cysts and compare their features with those found in the review of existing literature on ACLO and AL. Overall, thirteen cases of adrenal cysts were diagnosed and surgically excised during the study period, onto which we performed immunohistochemistry using a panel of antibodies (CD31, CD34, Pan Cytokeratin AE-1/AE-3, Factor VII, D2-40, and ERG). Four cases of ACLO and two AL were found. The lesions predominantly affected right adrenal, and the majority of patients were middle-age females, of Caucasian ethnicity, and asymptomatic. In our literature review, we found 108 cases of ACLO/AL from 57 articles with similar sex and age distribution. The diagnosis and subclassification of adrenal cysts are challenging, and there is a significant overlapping between the definition of ACLO and AL.


Assuntos
Neoplasias das Glândulas Suprarrenais , Cistos , Neoplasias das Glândulas Suprarrenais/diagnóstico , Neoplasias das Glândulas Suprarrenais/patologia , Cistos/patologia , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade
9.
Int J Mol Sci ; 23(4)2022 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-35216149

RESUMO

Polymeric materials have been extensively explored in the field of nanomedicine; within them, poly lactic-co-glycolic acid (PLGA) holds a prominent position in micro- and nanotechnology due to its biocompatibility and controllable biodegradability. In this review we focus on the combination of PLGA with different inorganic nanomaterials in the form of nanocomposites to overcome the polymer's limitations and extend its field of applications. We discuss their physicochemical properties and a variety of well-established synthesis methods for the preparation of different PLGA-based materials. Recent progress in the design and biomedical applications of PLGA-based materials are thoroughly discussed to provide a framework for future research.


Assuntos
Materiais Biocompatíveis/química , Nanocompostos/química , Nanomedicina/métodos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química
10.
J Oral Implantol ; 47(1): 31-35, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32662834

RESUMO

The perforation of the Schneiderian membrane (SM) is a common surgical complication during the sinus floor augmentation (SFA) procedure. Different approaches have been proposed to completely closer the SM perforation and to avoid graft contamination or migration and postoperative sinus infection. In this context, the leukocyte and platelet-rich fibrin (L-PRF) membranes have been proposed for SM perforation treatment because of their natural adhesive property and resistance. Thus, this case series aims to evaluate the effectiveness of L-PRF in the treatment of SM large perforations during SFA. A total of 9 SM perforations were treated in this case series. The L-PRF membranes were interposed on the perforated SM until the rupture could not be visualized. The maxillary sinus cavities were filled with deproteinized bovine mineral bone (Bio-oss, Geistlich, Switzerland), and a collagen membrane was positioned to cover the lateral access window. After 8 months, 13 implants were placed, achieving satisfactory primary stability. The osseointegration of all implants and absence of infection signs/mucus in the maxillary sinus were observed in cone beam computed tomography or panoramic radiography qualitative analysis after 3-5 years of follow-up. It can be concluded that the use of L-PRF can be considered a viable alternative for the repair of large SM perforations.


Assuntos
Fibrina Rica em Plaquetas , Levantamento do Assoalho do Seio Maxilar , Animais , Bovinos , Seguimentos , Humanos , Leucócitos , Seio Maxilar/diagnóstico por imagem , Seio Maxilar/cirurgia , Mucosa Nasal
11.
Anticancer Drugs ; 31(7): 718-727, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32568827

RESUMO

Conventional treatments for metastatic melanomas are still ineffective and generate numerous side effects, justifying the search for new therapies. The antimetastatic effect of the named N-(2-(4-bromophenylamino)-5-(trifluoromethyl)phenyl)nicotinamide (SRVIC30) compound has been previously demonstrated in murine melanoma. Herein, we aimed to evaluate its effect when topically administrated in a murine subcutaneous melanoma model. For that, mice C57BL/6 were injected subcutaneously with 2 × 10 B16-F10 cells. Topical treatment began when tumors became visible on animal's back. Therefore, tumor volume was measured three times a week until it reaches 12 mm approximately. At this point, 40 mg oil-in-water cream (Lanette) without (control mice; n = 10) or with SRVIC30 compound (SRVIC30 group; n = 10 animals) were spread daily over the tumor external surface using a small brush for 14 days. The treatments increased the percentage of peroxidase antioxidant enzyme and dead cells via caspase-3 activation, with a consequent deposit of collagen fibers in the tumors. In addition, the skin of treated animals showed the presence of inflammatory infiltrate. Finally, SRVIC30 did not show signs of toxicity. Thus, we concluded that the topic administration of SRVIC30 was able to influence crucial anticancer processes such as tumor cells apoptosis and surrounding microenvironment.


Assuntos
Melanoma Experimental/tratamento farmacológico , Niacinamida/análogos & derivados , Neoplasias Cutâneas/tratamento farmacológico , Administração Tópica , Animais , Caspase 3/metabolismo , Morte Celular/efeitos dos fármacos , Masculino , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Niacinamida/efeitos adversos , Niacinamida/farmacologia , Neoplasias Cutâneas/patologia
12.
Bioconjug Chem ; 30(3): 888-897, 2019 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-30742423

RESUMO

The combination of two imaging probes on the same biomolecule gives access to targeted bimodal imaging agents that can provide more accurate diagnosis, complementary information, or that may be used in different applications, such as nuclear imaging and fluorescence guided surgery. In this study, we demonstrate that dichlorotetrazine, a small, commercially available compound, can be used as a modular platform to easily assemble various imaging probes. Doubly labeled tetrazines can then be conjugated to a protein through a biorthogonal IEDDA reaction. A series of difunctionalized tetrazine compounds containing various chelating agents and fluorescent dyes was synthesized. As a proof of concept, one of these bimodal probes was conjugated to trastuzumab, previously modified with a constrained alkyne group, and the resulting dual-labeled antibody was evaluated in a mouse model, bearing a HER2-positive tumor. A significant uptake into tumor tissues was observed in vivo, by both SPECT-CT and fluorescence imaging, and confirmed ex vivo in biodistribution studies.


Assuntos
Meios de Contraste , Reação de Cicloadição , Imagem Multimodal , Animais , Corantes Fluorescentes/química , Humanos , Camundongos , Estudo de Prova de Conceito , Trastuzumab/química
13.
Eur J Nucl Med Mol Imaging ; 46(9): 1966-1977, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31161258

RESUMO

PURPOSE: Currently, the most commonly used chelator for labelling antibodies with 89Zr for immunoPET is desferrioxamine B (DFO). However, preclinical studies have shown that the limited in vivo stability of the 89Zr-DFO complex results in release of 89Zr, which accumulates in mineral bone. Here we report a novel chelator DFOcyclo*, a preorganized extended DFO derivative that enables octacoordination of the 89Zr radiometal. The aim was to compare the in vitro and in vivo stability of [89Zr]Zr-DFOcyclo*, [89Zr]Zr-DFO* and [89Zr]Zr-DFO. METHODS: The stability of 89Zr-labelled chelators alone and after conjugation to trastuzumab was evaluated in human plasma and PBS, and in the presence of excess EDTA or DFO. The immunoreactive fraction, IC50, and internalization rate of the conjugates were evaluated using HER2-expressing SKOV-3 cells. The in vivo distribution was investigated in mice with subcutaneous HER2+ SKOV-3 or HER2- MDA-MB-231 xenografts by PET/CT imaging and quantitative ex vivo tissue analyses 7 days after injection. RESULTS: 89Zr-labelled DFO, DFO* and DFOcyclo* were stable in human plasma for up to 7 days. In competition with EDTA, DFO* and DFOcyclo* showed higher stability than DFO. In competition with excess DFO, DFOcyclo*-trastuzumab was significantly more stable than the corresponding DFO and DFO* conjugates (p < 0.001). Cell binding and internalization were similar for the three conjugates. In in vivo studies, HER2+ SKOV-3 tumour-bearing mice showed significantly lower bone uptake (p < 0.001) 168 h after injection with [89Zr]Zr-DFOcyclo*-trastuzumab (femur 1.5 ± 0.3%ID/g, knee 2.1 ± 0.4%ID/g) or [89Zr]Zr-DFO*-trastuzumab (femur 2.0 ± 0.3%ID/g, knee 2.68 ± 0.4%ID/g) than after injection with [89Zr]Zr-DFO-trastuzumab (femur 4.5 ± 0.6%ID/g, knee 7.8 ± 0.6%ID/g). Blood levels, tumour uptake and uptake in other organs were not significantly different at 168 h after injection. HER2- MDA-MB-231 tumour-bearing mice showed significantly lower tumour uptake (p < 0.001) after injection with [89Zr]Zr-DFOcyclo*-trastuzumab (16.2 ± 10.1%ID/g) and [89Zr]Zr-DFO-trastuzumab (19.6 ± 3.2%ID/g) than HER2+ SKOV-3 tumour-bearing mice (72.1 ± 14.6%ID/g and 93.1 ± 20.9%ID/g, respectively), while bone uptake was similar. CONCLUSION: 89Zr-labelled DFOcyclo* and DFOcyclo*-trastuzumab showed higher in vitro and in vivo stability than the current commonly used 89Zr-DFO-trastuzumab. DFOcyclo* is a promising candidate to become the new clinically used standard chelator for 89Zr immunoPET.


Assuntos
Desferroxamina/química , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Radioisótopos/química , Zircônio/química , Animais , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Desferroxamina/farmacocinética , Feminino , Humanos , Camundongos , Distribuição Tecidual
14.
Toxicol Appl Pharmacol ; 356: 214-223, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30138656

RESUMO

The Serine/arginine-rich protein kinases (SRPK) are involved in pre-mRNA splicing control through the phosphorylation of the SR protein family of splicing factors. Over the last years, several studies have shown the relevance of SRPK for human cancers and their potential as promising drug targets. In this context, we have previously selected three trifluoromethyl arylamides (named here as SRVIC24, SRVIC30 and SRVIC36) with improved in vitro antileukemia effect and ability of impairing the cellular activity of SRPK. Given the increasing amount of reports on the implication of these kinases in metastatic cancers, in this study, we have evaluated the antimetastatic effect of these compounds and the known SRPK inhibitor (SRPIN340) on a murine model of metastatic melanoma. The compounds were able to impact the melanoma cell metastatic behavior by decreasing migration, invasion, adhesion, and colony formation in in vitro assays. Also, they presented antimetastatic in vivo activity, without apparent signs of systemic toxicity after treatments, as revealed by the histology of organs and analysis of key serum biochemical markers. Moreover, the effect of the treatments on SRPK1 nuclear translocation and SR protein phosphorylation was observed. Finally, molecular docking studies were carried out to gain structural information on the SRPK-compound complexes. Together, these data suggest that SRPK pharmacological inhibition should be considered as an interesting therapeutic strategy against metastatic cancers.


Assuntos
Antineoplásicos/farmacologia , Melanoma Experimental/tratamento farmacológico , Metástase Neoplásica/prevenção & controle , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , Invasividade Neoplásica , Niacinamida/análogos & derivados , Niacinamida/farmacologia , Niacinamida/uso terapêutico , Piperidinas/farmacologia , Piperidinas/uso terapêutico , Ensaio Tumoral de Célula-Tronco
15.
Org Biomol Chem ; 16(45): 8831-8836, 2018 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-30411777

RESUMO

Near-infrared (NIR) fluorescence imaging is a promising new medical imaging modality. Associated with a targeting molecule, NIR fluorophores can accumulate selectively in tissues of interest and become valuable tools for the diagnosis and therapy of various pathologies. To facilitate the design of targeted NIR imaging agents, it is important to identify simple and affordable fluorescent probes, allowing rapid labelling of biovectors such as proteins, ideally in a site-specific manner. Here, we demonstrate that heptamethine cyanine based fluorophores, such as IR-783, that contain a chloro-cyclohexyl moiety within their polymethine chain can react selectively, at neutral pH, with cysteine residues in proteins to give stable, site-specifically labelled conjugates, that emit in the NIR spectral window. This reaction is exemplified with the labelling of peptides and two protein models: albumin and a Fab' antibody fragment. The resulting fluorescent proteins are stable and suitable for in vivo NIR imaging applications, as shown on a mice model. This straightforward one-step procedure, that does not require the prior derivatisation of the fluorophore with a bioconjugatable handle, should facilitate the production and use of near-infrared labelled proteins in life sciences.


Assuntos
Carbocianinas/química , Cisteína/química , Corantes Fluorescentes/química , Raios Infravermelhos , Proteínas/química , Sequência de Aminoácidos , Animais , Carbocianinas/farmacocinética , Linhagem Celular Tumoral , Corantes Fluorescentes/farmacocinética , Halogenação , Camundongos , Imagem Óptica , Peptídeos/química , Coloração e Rotulagem , Distribuição Tecidual
16.
Angew Chem Int Ed Engl ; 57(33): 10646-10650, 2018 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-29905400

RESUMO

Dual-labeled biomolecules constitute a new generation of bioconjugates with promising applications in therapy and diagnosis. Unfortunately, the development of these new families of biologics is hampered by the technical difficulties associated with their construction. In particular, the site specificity of the conjugation is critical as the number and position of payloads can have a dramatic impact on the pharmacokinetics of the bioconjugate. Herein, we introduce dichlorotetrazine as a trivalent platform for the selective double modification of proteins on cysteine residues. This strategy is applied to the dual labeling of albumin with a macrocyclic chelator for nuclear imaging and a fluorescent probe for fluorescence imaging.


Assuntos
Albumina Sérica/química , Tetrazóis/química , Aminas/química , Sequência de Aminoácidos , Animais , Cisteína/química , Corantes Fluorescentes/química , Humanos , Camundongos , Imagem Óptica , Peptídeos/química , Peptídeos/metabolismo , Albumina Sérica/metabolismo , Distribuição Tecidual
17.
Bioconjug Chem ; 28(9): 2211-2223, 2017 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-28767228

RESUMO

Immuno-positron emission tomography (immunoPET) with 89Zr-labeled antibodies has shown great potential in cancer imaging. It can provide important information about the pharmacokinetics and tumor-targeting properties of monoclonal antibodies and may help in anticipating on toxicity. Furthermore, it allows accurate dose planning for individualized radioimmunotherapy and may aid in patient selection and early-response monitoring for targeted therapies. The most commonly used chelator for 89Zr is desferrioxamine (DFO). Preclinical studies have shown that DFO is not an ideal chelator because the 89Zr-DFO complex is partly unstable in vivo, which results in the release of 89Zr from the chelator and the subsequent accumulation of 89Zr in bone. This bone accumulation interferes with accurate interpretation and quantification of bone uptake on PET images. Therefore, there is a need for novel chelators that allow more stable complexation of 89Zr. In this Review, we will describe the most recent developments in 89Zr radiochemistry, including novel chelators and site-specific conjugation methods.


Assuntos
Quelantes/química , Imunoconjugados/química , Neoplasias/diagnóstico , Tomografia por Emissão de Pósitrons/métodos , Zircônio/química , Animais , Quelantes/farmacocinética , Desferroxamina/química , Desferroxamina/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Descoberta de Drogas/métodos , Humanos , Imunoconjugados/farmacocinética , Neoplasias/tratamento farmacológico , Neoplasias/terapia , Radioquímica/métodos , Radioisótopos/química , Radioisótopos/farmacocinética , Zircônio/farmacocinética
18.
J Urban Health ; 94(1): 43-53, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28028678

RESUMO

Advance care planning is relevant for homeless individuals because they experience high rates of morbidity and mortality. The impact of advance directive interventions on hospital care of homeless individuals has not been studied. The objective of this study was to determine if homeless individuals who complete an advance directive through a shelter-based intervention are more likely to have information from their advance directive documented and used during subsequent hospitalizations. The advance directive included preferences for life-sustaining treatments, resuscitation, and substitute decision maker(s). A total of 205 homeless men from a homeless shelter for men in Toronto, Canada, were enrolled in the study and offered an opportunity to complete an advance directive with the guidance of a trained counselor from April to June 2013. One hundred and three participants chose to complete an advance directive, and 102 participants chose to not complete an advance directive. Participants were provided copies of their advance directives. In addition, advance directives were electronically stored, and hospitals within a 1.0-mile radius of the shelter were provided access to the database. A prospective cohort study was performed using chart reviews to ascertain the documentation, availability, and use of advance directives, end-of-life care preferences, and medical treatments during hospitalizations over a 1-year follow-up period (April 2013 to June 2014) after the shelter-based advance directive intervention. Chart reviewers were blinded as to whether participants had completed an advance directive. The primary outcome was documentation or use of an advance directive during any hospitalization. The secondary outcome was documentation of end-of-life care preferences, without reference to an advance directive, during any hospitalization. After unblinding, charts were studied to determine whether advance directives were available, hospital care was consistent with patient preferences as documented in advance directives, and hospital resource utilization during admission. During the 1-year follow-up period, 38 participants who completed an advance directive and 37 participants who did not complete an advance directive had at least one hospitalization (36.9 vs. 36.2 %, p = 0.93). Participants who completed an advance directive were significantly more likely to have documentation or use of an advance directive in hospital, compared to participants who did not complete an advance directive (9.7 vs. 2.9 %, p = 0.047). Without reference to an advance directive, documentation of end-of-life care preferences occurred in 30.1 vs. 30.4 % of participants, respectively (p = 0.96), most often due to documentation of code status. There were no significant differences in resource utilization between admitted patients who completed and did not complete an advance directive. In conclusion, homeless men who complete an advance directive through a shelter-based intervention are more likely to have their detailed care preferences documented or used during subsequent hospitalizations.


Assuntos
Diretivas Antecipadas , Atenção à Saúde , Hospitalização , Pessoas Mal Alojadas , Idoso , Canadá , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos
19.
Ann Surg Oncol ; 23(12): 3831-3837, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27357178

RESUMO

BACKGROUND: Pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) can be used as an independent prognostic factor in neoadjuvant trials. The objective of this study was to determine the impact of Ki 67 expression and site of response on overall survival (OS) and disease-free survival (DFS) across different molecular subtypes of breast cancer following NAC. METHODS: Records from 357 patients who received NAC from 2004 to 2011 were reviewed. Univariate and multivariate analyses were performed to analyze clinical and pathological factors that influence pCR and DFS. RESULTS: Mean follow-up time was 45 months (range 12-112). pCR was achieved in 82 patients (23 %). According to molecular subtypes, rates of pCR were significantly higher for patients with HER2-positive and triple-negative tumors (69.4 and 32.7 %, respectively; p < 0.001) compared with other molecular subtypes. pCR was a predictive factor of longer OS and DFS. The hazard ratio for DFS in patients with positive lymph nodes (ypN1) after NAC was 2.48 (95 % confidence interval 1.47-4.19). Multivariate analysis showed that molecular subtype, changes in Ki 67 expression, and axillary lymph node response were significantly predictors of OS and DFS. CONCLUSIONS: pCR in the axilla and posttreatment changes in Ki 67 after NAC are associated with improved survival. Depending on axillary staging before NAC, detection of minimal residual disease-defined as the presence of isolated tumor cells in the SLN after NAC-may confer different prognosis. Further studies are needed to tailor treatments for patients with residual disease after NAC.


Assuntos
Antígeno Ki-67/metabolismo , Recidiva Local de Neoplasia/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/uso terapêutico , Axila , Quimioterapia Adjuvante , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Terapia Neoadjuvante , Neoplasia Residual , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Taxa de Sobrevida , Carga Tumoral
20.
Org Biomol Chem ; 14(19): 4511-8, 2016 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-27097718

RESUMO

Bombesin (BBN) was covalently bound to graftable subphthalocyanine (SubPc) or to a cholesterol derivative, a component of a liposome that encapsulates non-graftable SubPc. The latter bioconjugation approach was suitable to address the stability of SubPc and was achieved by copper-free click-chemistry on the outer-face of the liposome. Liposomes were purified (FPLC) and then analyzed in size (outer diameter about 60 nm measured by DLS). In vitro binding studies allowed to determine the IC50 13.9 nM for one component of the liposome, cholesterol, conjugated to BBN. Hence, azido- (or alkynyl-) liposomes give fluorophores with no reactive functional group available on their backbone a second chance to be (indirectly) bioconjugated (with bombesin).


Assuntos
Bombesina/química , Indóis/química , Lipossomos/química , Nanoestruturas/química , Alcinos/química , Azidas/química , Isoindóis
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