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1.
Artigo em Inglês | MEDLINE | ID: mdl-38888612

RESUMO

PURPOSE: Hepatic fibrosis develops as a response to chronic liver injury, resulting in the formation of fibrous scars. This process is initiated and driven by collagen-producing activated myofibroblasts which reportedly express high levels of platelet derived growth factor receptor-ß (PDGFRß). We therefore regard PDGFRß as an anchor for diagnosis and therapy. The Fibrobody® SP02SP26-ABD is a biparatopic VHH-construct targeting PDGFRß. Here, we explore its potential as a theranostic vector for liver fibrosis. METHODS: Specificity, cross-species binding, and cellular uptake of SP02SP26-ABD was assessed using human, mouse and rat PDGFRß ectodomains and PDGFRß-expressing cells. Cellular uptake by PDGFRß-expressing cells was also evaluated by equipping the Fibrobody® with auristatinF and reading out in vitro cytotoxicity. The validity of PDGFRß as a marker for active fibrosis was confirmed in human liver samples and 3 mouse models of liver fibrosis (DDC, CCl4, CDA-HFD) through immunohistochemistry and RT-PCR. After radiolabeling of DFO*-SP02SP26-ABD with 89Zr, its in vivo targeting ability was assessed in healthy mice and mice with liver fibrosis by PET-CT imaging, ex vivo biodistribution and autoradiography. RESULTS: SP02SP26-ABD shows similar nanomolar affinity for human, mouse and rat PDGFRß. Cellular uptake and hence subnanomolar cytotoxic potency of auristatinF-conjugated SP02SP26-ABD was observed in PDGFRß-expressing cell lines. Immunohistochemistry of mouse and human fibrotic livers confirmed co-localization of PDGFRß with markers of active fibrosis. In all three liver fibrosis models, PET-CT imaging and biodistribution analysis of [89Zr]Zr-SP02SP26-ABD revealed increased PDGFRß-specific uptake in fibrotic livers. In the DDC model, liver uptake was 12.15 ± 0.45, 15.07 ± 0.90, 20.23 ± 1.34, and 20.93 ± 4.35%ID/g after 1,2,3 and 4 weeks of fibrogenesis, respectively, compared to 7.56 ± 0.85%ID/g in healthy mice. Autoradiography revealed preferential uptake in the fibrotic (PDGFRß-expressing) periportal areas. CONCLUSION: The anti-PDGFRß Fibrobody® SP02SP26-ABD shows selective and high-degree targeting of activated myofibroblasts in liver fibrosis, and qualifies as a vector for diagnostic and therapeutic purposes.

2.
Int Endod J ; 56(1): 69-79, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36229181

RESUMO

AIM: To analyse the influence of ethylenediaminetetraacetic acid (EDTA) on the repair process in immature rat molars after a regenerative endodontic procedure (REP). METHODOLOGY: The lower first molars of 12 4-week-old Wistar rats underwent pulpectomy in the mesial root and were divided into the following groups: sodium hypochlorite (NaOCl; n = 6) - the mesial canals were irrigated with 2.5% NaOCl for 5 min, and NaOCl-EDTA (n = 6) - the canals were irrigated with 2.5% NaOCl, followed by 17% EDTA for 5 min each. After evoking bleeding using a size 10 K-file, the cavities were sealed. Three molars on the untreated side were randomly used as control (control-15 d; n = 3), and three molars from the other three rats untreated were used as immediate control (n = 3). After 15 days (NaOCl, NaOCl-EDTA and control-15 d groups) or immediately (control-immediate), the animals were euthanized, and the teeth were subjected to histologic evaluation of tissue regeneration and presence of collagen fibres. Mann-Whitney U-test was used (p < .05). RESULTS: The experimental groups had newly formed cementum-like tissue and increased root length and thickness. Half of the specimens in NaOCl-EDTA group showed apical foramen closure, whilst the NaOCl group had partial apical closure. The experimental groups showed inflammatory infiltrate extending mainly to the medium third of the root canal. These parameters were similar between experimental groups (p > .05). Newly formed connective tissue in the pulp space was significantly higher in the NaOCl-EDTA group than in NaOCl group (p < .05). Regarding the collagen fibres, the NaOCl-EDTA group had more collagen fibres in the root tip, but there was no significant difference compared to NaOCl group, and both groups showed greater amount of immature fibres in this area; in the centre of the apical third of root canal, there was equivalence between mature and immature fibres from both groups (p > .05). CONCLUSIONS: Ethylenediaminetetraacetic acid irrigation improved newly formed intracanal connective tissue after REP in immature molars of rats; however, EDTA did not influence cementum-like tissue formation, apical closure, inflammatory infiltrate and maturation of collagen fibres.


Assuntos
Colágeno , Animais , Ratos , Ácido Edético/farmacologia , Ácido Edético/uso terapêutico , Ratos Wistar
3.
Clin Oral Investig ; 27(11): 6291-6319, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37704917

RESUMO

OBJECTIVE: This systematic review/meta-analysis investigated the influence of NaOCl on cyclic fatigue resistance of endodontic NiTi instruments. MATERIALS AND METHODS: A systematic search until July 2022 in PubMed/MEDLINE, Embase, Scopus, Web of Science, SciELO, Cochrane Library, and grey literature was conducted. According to the PECOS strategy, only in vitro studies evaluating the effects of NaOCl on the cyclic fatigue resistance of NiTi instruments were eligible. Cyclic fatigue resistance was the primary outcome. A modified Joanna Briggs Institute's Checklist was used for risk of bias assessment. RESULTS: Of the 2,445 records screened, 37 studies were included. Most studies used simulated canals made of stainless-steel block with severe to moderate curvatures. NaOCl concentration varied from 1-6%, mainly at 37 °C. Regarding fatigue resistance, 23 studies using 1.2% to 6% NaOCl showed a reduction in the resistance compared to the control groups, especially when pre-heated. Four meta-analyses were performed according to the tested NiTi systems. The meta-analyses indicated that the PTU F2 files had higher reduction of fatigue resistance after exposure to 5.25% NaOCl; no differences between NaOCl and no immersion were observed for Reciproc R25, WaveOne 25.08, and WaveOne Gold Primary files. Included studies had low risk of bias. CONCLUSION: NaOCl appears to reduce cyclic fatigue resistance of certain NiTi files, especially when they are pre-heated, particularly in conventional NiTi files compared to some heat-treated instruments. It is possible that the temperature of the solution may have a greater influence on resistance than NaOCl itself. Important to note that an overall tendency toward no significant influence was observed among various systems. CLINICAL RELEVANCE: Precautions are necessary when a pre-heated high-concentration NaOCl is used to enhance its properties during root canal preparation, mainly using conventional wire.


Assuntos
Níquel , Hipoclorito de Sódio , Titânio , Preparo de Canal Radicular , Falha de Equipamento , Instrumentos Odontológicos , Desenho de Equipamento , Teste de Materiais
4.
Bioconjug Chem ; 33(1): 4-23, 2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-34894666

RESUMO

For the past two decades, atomic gold nanoclusters (AuNCs, ultrasmall clusters of several to 100 gold atoms, having a total diameter of <2 nm) have emerged as promising agents in the diagnosis and treatment of cancer. Owing to their small size, significant quantization occurs to their conduction band, which leads to emergent photonic properties and the disappearance of the plasmonic responses observed in larger gold nanoparticles. For example, AuNCs exhibit native luminescent properties, which have been well-explored in the literature. Using proteins, peptides, or other biomolecules as structural scaffolds or capping ligands, required for the stabilization of AuNCs, improves their biocompatibility, while retaining their distinct optical properties. This paved the way for the use of AuNCs in fluorescent bioimaging, which later developed into multimodal imaging combined with computer tomography and magnetic resonance imaging as examples. The development of AuNC-based systems for diagnostic applications in cancer treatment was then made possible by employing active or passive tumor targeting strategies. Finally, the potential therapeutic applications of AuNCs are extensive, having been used as light-activated and radiotherapy agents, as well as nanocarriers for chemotherapeutic drugs, which can be bound to the capping ligand or directly to the AuNCs via different mechanisms. In this review, we present an overview of the diverse biomedical applications of AuNCs in terms of cancer imaging, therapy, and combinations thereof, as well as highlighting some additional applications relevant to biomedical research.


Assuntos
Ouro
5.
Oral Dis ; 2022 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-35657117

RESUMO

OBJECTIVES: This systematic review (PROSPERO CRD42021227711) evaluated the influence of diabetes mellitus (DM) on the response of the pulp tissue and in the pulp cells behaviour. MATERIALS AND METHODS: Searches in PubMed/MEDLINE, Embase, Web of Science and OpenGrey were performed until March 2022. Studies evaluating the effects of DM in the pulp tissue inflammation and in the cell behaviour were included, followed by risk of bias assessment (Methodological Index for Non-Randomized Studies and SYRCLE's RoB tools). The meta-analysis was unfeasible, and a narrative synthesis for each outcome was provided. RESULTS: Of the 615 studies, 21 were eligible, mainly with in vivo analysis (16 studies). The pulp inflammation (10 studies) was analysed mainly by haematoxylin-eosin stain; DM increased pulp inflammation/degeneration in 9 studies, especially after dental procedures. The cell viability (5 studies) was analysed mostly using MTT assay; DM and glycating agents decreased cellular viability in 3 studies. DM reduced collagen in all of three studies. There were controversial results regarding mineralization; however, increased alkaline phosphatase was reported in three of four studies. CONCLUSIONS: DM seems to increase inflammation/degeneration and mineralization in the pulp tissue while reducing cell proliferation. Further analyses in human pulp are important to provide stronger evidence.

6.
Int Endod J ; 55(6): 579-612, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35305029

RESUMO

BACKGROUND: The effects of ethylenediaminetetraacetic acid (EDTA) on regenerative endodontic procedures (REPs) are controversial, because, despite releasing growth factors from dentine, some studies show negative effects on cell behaviour. OBJECTIVES: The aim of the study was to investigate the influence of the use of EDTA in REP on the growth factors' release, cell behaviour and tissue regeneration. METHODS: A systematic search was conducted (PubMed/Medline, Scopus, Cochrane Library, Web of Science, Embase, OpenGrey and reference lists) up to February 2021. Only in vivo and in vitro studies evaluating the effects of EDTA on the biological factors of dentine, pulp/periapical tissues and cell behaviour were eligible. Studies without a control group or available full text were excluded. The growth factors' release was the primary outcome. Risk of bias in the in vitro and in vivo studies was performed according to Joanna Briggs Institute's Checklist and SYRCLE's RoB tool, respectively. RESULTS: Of the 1848 articles retrieved, 36 were selected. Amongst these, 32 were in vitro, three animal studies and one with both models. The EDTA concentrations ranged from 3% to 15%, at different times. Regarding growth factors' release (17 studies), 15 studies found significant transforming growth factor (TGF)-ß release after dentine conditioning with EDTA, and most found no influence on vascular endothelial growth factor release. Regarding cell behaviour (26 studies), eight studies showed no influence of EDTA-treated dentine on cell viability, whereas, five, nine and six studies showed higher cell migration, adhesion and differentiation respectively. No influence of EDTA conditioning was observed in animal studies. In vitro studies had a low risk of bias, whereas animal studies had high risk of bias. Meta-analysis was unfeasible. DISCUSSION: This review found that EDTA increased TGF-ß release and improved cell activity. However, well-designed histological analyses using immature teeth models are needed. CONCLUSIONS: High-quality in vitro evidence suggests that EDTA-treated dentine positively influences TGF-ß release, cell migration, attachment and differentiation; further research to evaluate its influence on tissue regeneration is necessary due to low methodological quality of the animal studies.


Assuntos
Endodontia Regenerativa , Polpa Dentária , Ácido Edético/farmacologia , Fator de Crescimento Transformador beta , Fator A de Crescimento do Endotélio Vascular
7.
Int J Mol Sci ; 23(23)2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36499301

RESUMO

Nanoparticles (NPs) are commonly modified with tumor-targeting moieties that recognize proteins overexpressed on the extracellular membrane to increase their specific interaction with target cells. Nanobodies (Nbs), the variable domain of heavy chain-only antibodies, are a robust targeting ligand due to their small size, superior stability, and strong binding affinity. For the clinical translation of targeted Nb-NPs, it is essential to understand how the number of Nbs per NP impacts the receptor recognition on cells. To study this, Nbs targeting the hepatocyte growth factor receptor (MET-Nbs) were conjugated to PEGylated liposomes at a density from 20 to 800 per liposome and their targeting efficiency was evaluated in vitro. MET-targeted liposomes (MET-TLs) associated more profoundly with MET-expressing cells than non-targeted liposomes (NTLs). MET-TLs with approximately 150-300 Nbs per liposome exhibited the highest association and specificity towards MET-expressing cells and retained their targeting capacity when pre-incubated with proteins from different sources. Furthermore, a MET-Nb density above 300 Nbs per liposome increased the interaction of MET-TLs with phagocytic cells by 2-fold in ex vivo human blood compared to NTLs. Overall, this study demonstrates that adjusting the MET-Nb density can increase the specificity of NPs towards their intended cellular target and reduce NP interaction with phagocytic cells.


Assuntos
Nanopartículas , Neoplasias , Anticorpos de Domínio Único , Humanos , Lipossomos/química , Ligantes
8.
Transp Policy (Oxf) ; 112: 114-124, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36570325

RESUMO

Background: In this paper, we conduct a mobility reduction rate comparison between the first and second COVID-19 waves in several localities from America and Europe using Google community mobility reports (CMR) data. Through multi-dimensional visualization, we are able to compare the reduction in mobility from the different lockdown periods for each locality selected, simultaneously considering multiple place categories provided in CMR. In addition, our analysis comprises a 56-day lockdown period for each locality and COVID-19 wave, which we analyze both as 56-day periods and as 14-day consecutive windows. Methods: We use locality-wise calibrated CMR data, which we process through seasonal-trend decomposition by LOESS (STL) to isolate trend from seasonal and noise effects. We scale trend data to draw Pareto-compliant conclusions using radar charts. For each temporal granularity considered, data for a given place category is aggregated using the area under the curve (AUC) approach. Results: In general, reduction rates observed during the first wave were much higher than during the second. Alarmingly, December holiday season mobility in some of the localities reached pre-pandemic levels for some of the place categories reported. Manaus was the only locality where second wave mobility was nearly as reduced as during the first wave, likely due to the P1 variant outbreak and oxygen supply crisis.

9.
Mol Pharm ; 17(4): 1276-1292, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32142290

RESUMO

meta-Tetra(hydroxyphenyl)chlorin (mTHPC) is one of the most potent second-generation photosensitizers, clinically used for photodynamic therapy (PDT) of head and neck squamous cell carcinomas. However, improvements are still required concerning its present formulation (i.e., Foscan, a solution of mTHPC in ethanol/propylene glycol (40:60 w/w)), as mTHPC has the tendency to aggregate in aqueous media, e.g., biological fluids, and it has limited tumor specificity. In the present study, polymeric micelles with three different diameters (17, 24, and 45 nm) based on benzyl-poly(ε-caprolactone)-b-poly(ethylene glycol) (PCLn-PEG; n = 9, 15, or 23) were prepared with mTHPC loadings ranging from 0.5 to 10 wt % using a film-hydration method as advanced nanoformulations for this photosensitizer. To favor the uptake of the micelles by cancer cells that overexpress the epidermal growth factor receptor (EGFR), the micelles were decorated with an EGFR-targeted nanobody (named EGa1) through maleimide-thiol chemistry. The enhanced binding of the EGFR-targeted micelles at 4 °C to EGFR-overexpressing A431 cells, compared to low-EGFR-expressing HeLa cells, confirmed the specificity of the micelles. In addition, an enhanced uptake of mTHPC-loaded micelles by A431 cells was observed when these were decorated with the EGa1 nanobody, compared to nontargeted micelles. Both binding and uptake of targeted micelles were blocked by an excess of free EGa1 nanobody, demonstrating that these processes occur through EGFR. In line with this, mTHPC loaded in EGa1-conjugated PCL23-PEG (EGa1-P23) micelles demonstrated 4 times higher photocytotoxicity on A431 cells, compared to micelles lacking the nanobody. Importantly, EGa1-P23 micelles also showed selective PDT against A431 cells compared to the low-EGFR-expressing HeLa cells. Finally, an in vivo pharmacokinetic study shows that after intravenous injection, mTHPC incorporated in the P23 micelles displayed prolonged blood circulation kinetics, compared to free mTHPC, independently of the presence of EGa1. Thus, these results make these micelles a promising nanomedicine formulation for selective therapy.


Assuntos
Mesoporfirinas/farmacologia , Polímeros/química , Anticorpos de Domínio Único/química , Anticorpos de Domínio Único/farmacologia , Animais , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos/métodos , Receptores ErbB/metabolismo , Etilenoglicóis/química , Feminino , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Micelas , Nanomedicina/métodos , Nanopartículas/química , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Poliésteres/química , Polietilenoglicóis/química
10.
Mol Pharm ; 16(4): 1633-1647, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30817164

RESUMO

In cancer treatment, polymeric nanoparticles (NPs) can serve as a vehicle for the delivery of cytotoxic proteins that have intracellular targets but that lack well-defined mechanisms for cellular internalization, such as saporin. In this work, we have prepared PEGylated poly(lactic acid- co-glycolic acid- co-hydroxymethyl glycolic acid) (PLGHMGA) NPs for the selective delivery of saporin in the cytosol of HER2 positive cancer cells. This selective uptake was achieved by decorating the surface of the NPs with the 11A4 nanobody that is specific for the HER2 receptor. Confocal microscopy observations showed rapid and extensive uptake of the targeted NPs (11A4-NPs) by HER2 positive cells (SkBr3) but not by HER2 negative cells (MDA-MB-231). This selective uptake was blocked upon preincubation of the cells with an excess of nanobody. Nontargeted NPs (Cys-NPs) were not taken up by either type of cells. Importantly, a dose-dependent cytotoxic effect was only observed on SkBr3 cells when these were treated with saporin-loaded 11A4-NPs in combination with photochemical internalization (PCI), a technique that uses a photosensitizer and local light exposure to facilitate endosomal escape of entrapped nanocarriers and biomolecules. The combined use of saporin-loaded 11A4-NPs and PCI strongly inhibited cell proliferation and decreased cell viability through induction of apoptosis. Also the cytotoxic effect could be reduced by an excess of nanobody, reinforcing the selectivity of this system. These results suggest that the combination of the targeting nanobody on the NPs with PCI are effective means to achieve selective uptake and cytotoxicity of saporin-loaded NPs.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Nanopartículas/administração & dosagem , Polímeros/química , Receptor ErbB-2/metabolismo , Saporinas/administração & dosagem , Anticorpos de Domínio Único/administração & dosagem , Antineoplásicos/farmacologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proliferação de Células , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Nanopartículas/química , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Poliésteres/química , Saporinas/química , Anticorpos de Domínio Único/imunologia , Células Tumorais Cultivadas
11.
Mol Pharm ; 16(7): 3145-3156, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31244224

RESUMO

Photodynamic therapy (PDT) eradicates tumors by the local activation of a photosensitizer with near-infrared light. One of the aspects hampering the clinical use of PDT is the poor selectivity of the photosensitizer. To improve this, we have recently introduced a new approach for targeted PDT by conjugating photosensitizers to nanobodies. Diverse G protein-coupled receptors (GPCRs) show aberrant overexpression in tumors and are therefore interesting targets in cancer therapy. Here we show that GPCR-targeting nanobodies can be used in targeted PDT. We have developed a nanobody binding the extracellular side of the viral GPCR US28, which is detected in tumors like glioblastoma. The nanobody was site-directionally conjugated to the water-soluble photosensitizer IRDye700DX. This nanobody-photosensitizer conjugate selectively killed US28-expressing glioblastoma cells both in 2D and 3D cultures upon illumination with near-infrared light. This is the first example employing a GPCR as target for nanobody-directed PDT. With the emerging role of GPCRs in cancer, this data provides a new angle for exploiting this large family of receptors for targeted therapies.


Assuntos
Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Imunoconjugados/farmacologia , Indóis/química , Compostos de Organossilício/química , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Receptores de Quimiocinas/metabolismo , Anticorpos de Domínio Único/química , Anticorpos de Domínio Único/metabolismo , Proteínas Virais/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Células HEK293 , Humanos , Imunoconjugados/uso terapêutico , Indóis/uso terapêutico , Raios Infravermelhos/uso terapêutico , Compostos de Organossilício/uso terapêutico , Fármacos Fotossensibilizantes/uso terapêutico , Anticorpos de Domínio Único/administração & dosagem , Transfecção
12.
Lasers Surg Med ; 50(5): 513-522, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29777587

RESUMO

OBJECTIVE: The aim of this study was to investigate the effects of targeted photoimmunotherapy (PIT) in vitro on cell lines with various expression levels of epidermal growth factor receptor (EGFR) using an anti-EGFR targeted conjugate composed of Cetuximab and IR700DX, phthalocyanine dye. MATERIALS AND METHODS: Relative EGFR density and cell binding assay was conducted in three human head & neck cancer cell lines (scc-U2, scc-U8, and OSC19) and one reference cell line A431. After incubation with the conjugate for 1 or 24 hours, cellular uptake and localization were investigated by confocal laser scanning microscopy and quantified by image analysis. Cell survival was determined using the MTS assay and alamarBlue assay after PIT with a 690 nm laser to a dose of 7 J.cm-2 (at 5 mW.cm-2 ). The mode of cell death was examined with flow cytometry using apoptosis/necrosis staining by Annexin V/propidium iodide, together with immunoblots of anti-apoptotic Bcl-2 family proteins Bcl-2 and Bcl-xL. RESULTS: A431 cells had the highest EGFR density followed by OSC19, and then scc-U2 and scc-U8. The conjugates were localized both on the surface and in the cytosol of the cells after 1- and 24-hour incubation. After 24-hour incubation the granular pattern was more pronounced and in a similar pattern of a lysosomal probe, suggesting that the uptake of conjugates by cells was via receptor-mediated endocytosis. The results obtained from the quantitative imaging analysis correlate with the level of EGFR expression. Targeted PIT killed scc-U8 and A431 cells efficiently; while scc-U2 and OSC19 were less sensitive to this treatment, despite having similar EGFR density, uptake and localization pattern. Scc-U2 cells showed less apoptotic cell dealth than in A431 after 24-hour targeted PIT. Immunoblots showed significantly higher expression of anti-apoptotic Bcl-2 and Bcl-xL proteins in scc-U2 cell lines compared to scc-U8. CONCLUSION: Our study suggests that the effectiveness of EGFR targeted PIT is not only dependent upon EGFR density. Intrinsic biological properties of tumor cell lines also play a role in determining the efficacy of targeted PIT. We have shown that in scc-U2 cells this difference may be caused by differences in the apoptopic pathway. Lasers Surg. Med. 50:513-522, 2018. © 2018 Wiley Periodicals, Inc.


Assuntos
Receptores ErbB/efeitos dos fármacos , Neoplasias de Cabeça e Pescoço/terapia , Imunoterapia , Indóis/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Antineoplásicos/uso terapêutico , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Cetuximab/uso terapêutico , Receptores ErbB/metabolismo , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Isoindóis
13.
Nanomedicine ; 10(7): 1441-51, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24394212

RESUMO

Photodynamic therapy (PDT) induces cell death through light activation of a photosensitizer (PS). Targeted delivery of PS via monoclonal antibodies has improved tumor selectivity. However, these conjugates have long half-lives, leading to relatively long photosensitivity in patients. In an attempt to target PS specifically to tumors and to accelerate PS clearance, we have developed new conjugates consisting of nanobodies (NB) targeting the epidermal growth factor receptor (EGFR) and a traceable PS (IRDye700DX). These fluorescent conjugates allow the distinction of cell lines with different expression levels of EGFR. Results show that these conjugates specifically induce cell death of EGFR overexpressing cells in low nanomolar concentrations, while PS alone or the NB-PS conjugates in the absence of light induce no toxicity. Delivery of PS using internalizing biparatopic NB-PS conjugates results in even more pronounced phototoxicities. Altogether, EGFR-targeted NB-PS conjugates are specific and potent, enabling the combination of molecular imaging with cancer therapy. From the clinical editor: This study investigates the role of EGFR targeting nanobodies to deliver traceable photosensitizers to cancer molecules for therapeutic exploitation and concomitant imaging. Altogether, EGFR-targeted NB-PS conjugates combine molecular imaging with cancer therapy, the method is specific and potent, paving the way to clinical application of this technology.


Assuntos
Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Anticorpos de Domínio Único , Animais , Técnicas de Cocultura , Receptores ErbB/imunologia , Camundongos , Células NIH 3T3
14.
Mycorrhiza ; 24(1): 55-64, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23812655

RESUMO

The composition and diversity of fungal communities associated with three endangered orchid species, Hadrolaelia jongheana, Hoffmannseggella caulescens, and Hoffmannseggella cinnabarina, found in different vegetation formations of the Atlantic Forest were determined by constructing clone libraries and by applying diversity and richness indices. Our results demonstrated the presence of Basidiomycetes. Sebacinales (81.61%) and Cantharellales (12.10%) were the dominant orders and are potential candidates for orchid mycorrhizal fungi. The Ascomycetes identified included the Helotiales (29.31%), Capnodiales (18.10%), and Sordariales (10.34%), among others. These orders may represent potentially endophytic fungi. A Shannon-Wiener diversity index (H') analysis showed a relatively high fungal community diversity associated with these tropical orchids. This diversity may offer greater flexibility in terms of the adaptation of the plants to changing environmental conditions and the potential facilitation of reintroduction programs. The Simpson diversity index values showed that all of the libraries included dominant species, and a LIBSHUFF analysis showed that the fungal communities were structurally different from each other, suggesting an influence of local factors on this diversity. This study offers important information for the development of conservation strategies for threatened and endemic species of Brazilian flora in an important and threatened hotspot.


Assuntos
Espécies em Perigo de Extinção , Endófitos/fisiologia , Fungos/fisiologia , Micorrizas/fisiologia , Orchidaceae/microbiologia , Raízes de Plantas/microbiologia , Árvores/microbiologia , Biodiversidade , Brasil , DNA Espaçador Ribossômico/genética , Endófitos/genética , Fungos/classificação , Fungos/genética , Micorrizas/classificação , Micorrizas/genética , Filogenia , Solo/química
15.
Top Stroke Rehabil ; 21(6): 484-94, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25467396

RESUMO

BACKGROUND: The presence of sensory and motor deficits is common in patients post stroke. Mental practice (MP) and mirror therapy (MT) can be used as therapeutic techniques for poststroke rehabilitation. Important results have been demonstrated, although they have not established the patients' functional gain or related results of muscle electromyographic (EMG) data to functionality. OBJECTIVE: The aim was to investigate EMG activity and sensory, motor, and functional performance in hemiparetic limbs of patients with stroke after intervention with MP and MT associated with conventional physical therapy training (CPTT). METHODS: Seven patients were treated twice weekly during 8 weeks with MP and MT associated with CPTT of the affected upper limb. The Fugl-Meyer scale and the Barthel Index (BI) were applied to assess sensorimotor ability and independence of patients. Activation of the upper trapezius, biceps brachii, triceps brachii, flexor carpi ulnaris, and extensor carpi radialis was evaluated by means of EMG symmetry index and muscle co-activation measurements. RESULTS: There were statistically significant differences between pre- and postassessment findings for the motor, sensory, and mobility domains of the Fugl-Meyer scale, as well as for BI evaluation. No statistically significant differences were observed when the pre- and posttest symmetry and co-activation data were compared, although there were qualitative changes. CONCLUSIONS: The protocol was effective for improving motor, sensory, and mobility aspects, as well as function involved in activities of daily living. Qualitative changes in symmetry and muscle co-contraction were found, indicating a possible improvement in upper limb rehabilitation of patients with stroke.


Assuntos
Processos Mentais/fisiologia , Movimento/fisiologia , Paresia/reabilitação , Modalidades de Fisioterapia/instrumentação , Reabilitação do Acidente Vascular Cerebral , Adulto , Vias Aferentes/fisiologia , Idoso , Braço/fisiologia , Vias Eferentes/fisiologia , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Contração Muscular/fisiologia , Paresia/fisiopatologia , Projetos Piloto , Estudos Prospectivos , Acidente Vascular Cerebral/fisiopatologia , Resultado do Tratamento
16.
Front Mol Biosci ; 11: 1389548, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38784667

RESUMO

The global impact of zoonotic viral outbreaks underscores the pressing need for innovative antiviral strategies, particularly against respiratory zoonotic RNA viruses. These viruses possess a high potential to trigger future epidemics and pandemics due to their high mutation rate, broad host range and efficient spread through airborne transmission. Recent pandemics caused by coronaviruses and influenza A viruses underscore the importance of developing targeted antiviral strategies. Single-domain antibodies (sdAbs), originating from camelids, also known as nanobodies or VHHs (Variable Heavy domain of Heavy chain antibodies), have emerged as promising tools to combat current and impending zoonotic viral threats. Their unique structure, coupled with attributes like robustness, compact size, and cost-effectiveness, positions them as strong alternatives to traditional monoclonal antibodies. This review describes the pivotal role of sdAbs in combating respiratory zoonotic viruses, with a primary focus on enhancing sdAb antiviral potency through optimization techniques and diverse administration strategies. We discuss both the promises and challenges within this dynamically growing field.

17.
Neotrop Entomol ; 53(2): 391-399, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38347318

RESUMO

The peanut thrips, Enneothrips enigmaticus (Thysanoptera: Thrypidae), is an important pest of the peanut (Arachis hypogaea) in South America. Due to concerns about the environment and human health induced by the extensive use of pesticides in the management control of pests, environmentally and friendlier tactics must be targeted. Thus, this study investigates, for the first time, the behavior of Xylocoris sordidus (Hemiptera: Anthocoridae) as a biological control agent for E. enigmaticus. The methodology included no-choice tests to assess whether the predation rate varies according to the developmental stage of the prey, as well as the predator's developmental stage with the highest predation capacity. Additionally, an analysis of the functional response of adult and 5th instar nymphs of X. sordidus exposed to different densities of E. enigmaticus nymphs (1, 2, 4, 8, 16, and 32) was conducted. The results confirm the predation of peanut thrips by X. sordidus, with a higher predation rate in the nymphal stages of the prey. There was no difference in predation capacity between predator nymphs and adults, and exhibiting a type II functional response. Therefore, the potential of X. sordidus as a biological control agent for E. enigmaticus is confirmed, showing the importance of adopting measures to preserve this predator in peanut crops.


Assuntos
Hemípteros , Heterópteros , Tisanópteros , Humanos , Animais , Agentes de Controle Biológico , Heterópteros/fisiologia , Comportamento Predatório , Ninfa/fisiologia , Arachis , Controle Biológico de Vetores
18.
Int J Pharm ; 655: 124004, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38492899

RESUMO

Photodynamic therapy (PDT) is a suitable alternative to currently employed cancer treatments. However, the hydrophobicity of most photosensitizers (e.g., zinc phthalocyanine (ZnPC)) leads to their aggregation in blood. Moreover, non-specific accumulation in skin and low clearance rate of ZnPC leads to long-lasting skin photosensitization, forcing patients with a short life expectancy to remain indoors. Consequently, the clinical implementation of these photosensitizers is limited. Here, benzyl-poly(ε-caprolactone)-b-poly(ethylene glycol) micelles encapsulating ZnPC (ZnPC-M) were investigated to increase the solubility of ZnPC and its specificity towards cancers cells. Asymmetric flow field-flow fractionation was used to characterize micelles with different ZnPC-to-polymer ratios and their stability in human plasma. The ZnPC-M with the lowest payload (0.2 and 0.4% ZnPC w/w) were the most stable in plasma, exhibiting minimal ZnPC transfer to lipoproteins, and induced the highest phototoxicity in three cancer cell lines. Nanobodies (Nbs) with binding specificity towards hepatocyte growth factor receptor (MET) or epidermal growth factor receptor (EGFR) were conjugated to ZnPC-M to facilitate cell targeting and internalization. MET- and EGFR-targeting micelles enhanced the association and the phototoxicity in cells expressing the target receptor. Altogether, these results indicate that ZnPC-M decorated with Nbs targeting overexpressed proteins on cancer cells may provide a better alternative to currently approved formulations.


Assuntos
Isoindóis , Compostos Organometálicos , Fotoquimioterapia , Humanos , Fármacos Fotossensibilizantes/química , Micelas , Polímeros , Fotoquimioterapia/métodos , Compostos de Zinco , Compostos Organometálicos/farmacologia , Compostos Organometálicos/química , Receptores ErbB , Linhagem Celular Tumoral
19.
PLoS One ; 19(3): e0300069, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38457402

RESUMO

INTRODUCTION: Implant infections caused by Staphylococcus aureus are responsible for high mortality and morbidity worldwide. Treatment of these infections can be difficult especially when bacterial biofilms are involved. In this study we investigate the potential of infrared photoimmunotherapy to eradicate staphylococcal infection in a mouse model. METHODS: A monoclonal antibody that targets Wall Teichoic Acid surface components of both S. aureus and its biofilm (4497-IgG1) was conjugated to a photosensitizer (IRDye700DX) and used as photoimmunotherapy in vitro and in vivo in mice with a subcutaneous implant pre-colonized with biofilm of Staphylococcus aureus. A dose of 400 µg and 200 µg of antibody-photosensitizer conjugate 4497-IgG-IRDye700DXwas administered intravenously to two groups of 5 mice. In addition, multiple control groups (vancomycin treated, unconjugated IRDye700DX and IRDye700DX conjugated to a non-specific antibody) were used to verify anti-microbial effects. RESULTS: In vitro results of 4497-IgG-IRDye700DX on pre-colonized (biofilm) implants showed significant (p<0.01) colony-forming units (CFU) reduction at a concentration of 5 µg of the antibody-photosensitizer conjugate. In vivo, treatment with 4497-IgG-IRDye700DX showed no significant CFU reduction at the implant infection. However, tissue around the implant did show a significant CFU reduction with 400 µg 4497-IgG-IRDye700DX compared to control groups (p = 0.037). CONCLUSION: This study demonstrated the antimicrobial potential of photoimmunotherapy for selectively eliminating S. aureus in vivo. However, using a solid implant instead of a catheter could result in an increased bactericidal effect of 4497-IgG-IRDye700DX and administration locally around an implant (per operative) could become valuable applications in patients that are difficult to treat with conventional methods. We conclude that photoimmunotherapy could be a potential additional therapy in the treatment of implant related infections, but requires further improvement.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Humanos , Animais , Camundongos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Biofilmes , Imunoglobulina G/farmacologia
20.
Biochim Biophys Acta Proteins Proteom ; 1872(1): 140970, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-37871810

RESUMO

J-domain proteins (JDPs) form a very large molecular chaperone family involved in proteostasis processes, such as protein folding, trafficking through membranes and degradation/disaggregation. JDPs are Hsp70 co-chaperones capable of stimulating ATPase activity as well as selecting and presenting client proteins to Hsp70. In mitochondria, human DjC20/HscB (a type III JDP that possesses only the conserved J-domain in some region of the protein) is involved in [FeS] protein biogenesis and assists human mitochondrial Hsp70 (HSPA9). Human DjC20 possesses a zinc-finger domain in its N-terminus, which closely contacts the J-domain and appears to be essential for its function. Here, we investigated the hDjC20 structure in solution as well as the importance of Zn+2 for its stability. The recombinant hDjC20 was pure, folded and capable of stimulating HSPA9 ATPase activity. It behaved as a slightly elongated monomer, as attested by small-angle X-ray scattering and SEC-MALS. The presence of Zn2+ in the hDjC20 samples was verified, a stoichiometry of 1:1 was observed, and its removal by high concentrations of EDTA and DTPA was unfeasible. However, thermal and chemical denaturation in the presence of EDTA led to a reduction in protein stability, suggesting a synergistic action between the chelating agent and denaturators that facilitate protein unfolding depending on metal removal. These data suggest that the affinity of Zn+2 for the protein is very high, evidencing its importance for the hDjC20 structure.


Assuntos
Proteínas de Choque Térmico HSP70 , Proteínas de Choque Térmico , Humanos , Adenosina Trifosfatases/metabolismo , Ácido Edético , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico HSP70/química , Chaperonas Moleculares/química
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