Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Hazard Mater ; 473: 134686, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38788582

RESUMO

Hexagonal boron nitride (hBN) is an emerging two-dimensional material attracting considerable attention in the industrial sector given its innovative physicochemical properties. Potential risks are associated mainly with occupational exposure where inhalation and skin contact are the most relevant exposure routes for workers. Here we aimed at characterizing the effects induced by composites of thermoplastic polyurethane (TPU) and hBN, using immortalized HaCaT skin keratinocytes and BEAS-2B bronchial epithelial cells. The composite was abraded using a Taber® rotary abraser and abraded TPU and TPU-hBN were also subjected to photo-Fenton-mediated degradation mimicking potential weathering across the product life cycle. Cells were exposed to the materials for 24 h (acute exposure) or twice per week for 4 weeks (chronic exposure) and evaluated with respect to material internalization, cytotoxicity, and proinflammatory cytokine secretion. Additionally, comprehensive mass spectrometry-based proteomics and metabolomics (secretomics) analyses were performed. Overall, despite evidence of cellular uptake of the material, no significant cellular and/or protein expression profiles alterations were observed after acute or chronic exposure of HaCaT or BEAS-2B cells, identifying only few pro-inflammatory proteins. Similar results were obtained for the degraded materials. These results support the determination of hazard profiles associated with cutaneous and pulmonary hBN-reinforced polymer composites exposure.


Assuntos
Compostos de Boro , Poliuretanos , Humanos , Poliuretanos/toxicidade , Poliuretanos/química , Compostos de Boro/química , Compostos de Boro/toxicidade , Linhagem Celular , Pele/efeitos dos fármacos , Pele/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Citocinas/metabolismo , Sobrevivência Celular/efeitos dos fármacos
2.
J Control Release ; 368: 566-579, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38438093

RESUMO

Intravenous (IV) iron-carbohydrate complexes are widely used nanoparticles (NPs) to treat iron deficiency anaemia, often associated with medical conditions such as chronic kidney disease, heart failure and various inflammatory conditions. Even though a plethora of physicochemical characterisation data and clinical studies are available for these products, evidence-based correlation between physicochemical properties of iron-carbohydrate complexes and clinical outcome has not fully been elucidated yet. Studies on other metal oxide NPs suggest that early interactions between NPs and blood upon IV injection are key to understanding how differences in physicochemical characteristics of iron-carbohydrate complexes cause variance in clinical outcomes. We therefore investigated the core-ligand structure of two clinically relevant iron-carbohydrate complexes, iron sucrose (IS) and ferric carboxymaltose (FCM), and their interactions with two structurally different human plasma proteins, human serum albumin (HSA) and fibrinogen, using a combination of cryo-scanning transmission electron microscopy (cryo-STEM), x-ray diffraction (XRD), small-angle x-ray scattering (SAXS) and small-angle neutron scattering (SANS). Using this orthogonal approach, we defined the nano-structure, individual building blocks and surface morphology for IS and FCM. Importantly, we revealed significant differences in the surface morphology of the iron-carbohydrate complexes. FCM shows a localised carbohydrate shell around its core, in contrast to IS, which is characterised by a diffuse and dynamic layer of carbohydrate ligand surrounding its core. We hypothesised that such differences in carbohydrate morphology determine the interaction between iron-carbohydrate complexes and proteins and therefore investigated the NPs in the presence of HSA and fibrinogen. Intriguingly, IS showed significant interaction with HSA and fibrinogen, forming NP-protein clusters, while FCM only showed significant interaction with fibrinogen. We postulate that these differences could influence bio-response of the two formulations and their clinical outcome. In conclusion, our study provides orthogonal characterisation of two clinically relevant iron-carbohydrate complexes and first hints at their interaction behaviour with proteins in the human bloodstream, setting a prerequisite towards complete understanding of the correlation between physicochemical properties and clinical outcome.


Assuntos
Anemia Ferropriva , Maltose/análogos & derivados , Nanopartículas Metálicas , Humanos , Ferro/química , Espalhamento a Baixo Ângulo , Ligantes , Difração de Raios X , Compostos Férricos , Óxido de Ferro Sacarado/uso terapêutico , Anemia Ferropriva/tratamento farmacológico , Nanopartículas Metálicas/química , Fibrinogênio
3.
J Clin Med ; 11(24)2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36555918

RESUMO

Background: Knee osteoarthritis (KOA) is a chronic degenerative pathology that is associated with multiple risk factors such as age, sex, obesity, or metabolic syndrome (MetS). The present clinical trial aimed to investigate the influence of the environment of origin, body mass index (BMI), and MetS parameters on the KOA differentiated degrees. Methods: 85 patients were admitted for the clinical study. The KOA presence was investigated using X-rays analysis. The Kellgren−Lawrence classification (KL) of the KOA severity and the MetS characteristic parameters using freshly collected blood were performed for each patient. All data collected were used for ANOVA statistic interpretation. Results: The total cholesterol and glycemia were found to be statistically significant (p < 0.028, and p < 0.03, respectively), with a high level in patients with severe KOA compared to healthy ones. Patients from rural regions are 5.18 times more prone to develop severe KOA when compared to ones from urban areas. Conclusions: The results of the statistical analysis confirmed the correlation between the incidence and severity of KOA and the influence of increased values of BMI, glycemia, triglycerides, and total cholesterol. The investigations revealed a statistically significant influence of the environment of origin on the KOA degree of the patients.

4.
Membranes (Basel) ; 12(3)2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35323778

RESUMO

(1) Background: The standard treatment for periodontal disease, a chronic inflammatory state caused by the interaction between biofilms generated by organized oral bacteria and the local host defense response, consists of calculus and biofilm removal through mechanical debridement, associated with antimicrobial therapy that could be delivered either systemically or locally. The present study aimed to determine the effectiveness of a hyaluronic acid membrane matrix as a carrier for the controlled release of the active compounds of a formulation proposed as a topical treatment for periodontal disease, and the influence of pH on the complex system's stability. (2) Methods: The obtained hyaluronic acid (HA) hydrogel membrane with dispersed melatonin (MEL), metronidazole (MZ), and tetracycline (T) was completely characterized through FTIR, XRD, thermal analysis, UV-Vis and fluorescence spectroscopy, fluorescence microscopy, zeta potential and dielectric analysis. The MTT viability test was applied to check the cytotoxicity of the obtained membranes, while the microbiological assessment was performed against strains of Staphylococcus spp. and Streptococcus spp. The spectrophotometric investigations allowed to follow up the release profile from the HA matrix for MEL, MZ, and T present in the topical treatment considered. We studied the behavior of the active compounds against the pH of the generated environment, and the release profile of the bioactive formulation based on the specific comportment towards pH variation. The controlled delivery of the bioactive compounds using HA as a supportive matrix was modeled applying Korsmeyer-Peppas, Higuchi, first-order kinetic models, and a newly proposed pseudo-first-order kinetic model. (3) Results: It was observed that MZ and T were released at higher active concentrations than MEL when the pH was increased from 6.75, specific for patients with periodontitis, to a pH of 7.10, characterizing the healthy patients. Additionally, it was shown that for MZ, there is a burst delivery up to 2.40 × 10-5 mol/L followed by a release decrease, while for MEL and T a short release plateau was recorded up to a concentration of 1.80 × 10-5 mol/L for MEL and 0.90 × 10-5 mol/L for T, followed by a continuous release; (4) Conclusions: The results are encouraging for the usage of the HA membrane matrix as releasing vehicle for the active components of the proposed topical treatment at a physiological pH.

5.
Biosens Bioelectron ; 171: 112666, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33069958

RESUMO

We present a new method for electrochemical sensing, which compensates the fouling effect of propofol through machine learning (ML) model. Direct and continuous monitoring of propofol is crucial in the development of automatic systems for control of drug infusion in anaesthesiology. The fouling effect on electrodes discourages the possibility of continuous online monitoring of propofol since polymerization of the surface produces sensor drift. Several approaches have been proposed to limit the phenomenon at the biochemical interface; instead, here, we present a novel ML-based calibration procedure. In this paper, we analyse a dataset of 600 samples acquired through staircase cyclic voltammetry (SCV), resembling the scenario of continuous monitoring of propofol, both in PBS and in undiluted human serum, to demonstrate that ML-based model solves electrode fouling of anaesthetics. The proposed calibration approach is based on Gaussian radial basis function support vector classifier (RBF-SVC) that achieves classification accuracy of 98.9% in PBS, and 100% in undiluted human serum. The results prove the ability of the ML-based model to correctly classify propofol concentration in the therapeutic range between 1µM and 60µM with levels of 10µM, continuously up to ten minutes, with one sample every 30s.


Assuntos
Técnicas Biossensoriais , Propofol , Eletrodos , Humanos , Propofol/sangue
6.
Sci Data ; 7(1): 169, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32503988

RESUMO

Modern histopathology workflows rely on the digitization of histology slides. The quality of the resulting digital representations, in the form of histology slide image mosaics, depends on various specific acquisition conditions and on the image processing steps that underlie the generation of the final mosaic, e.g. registration and blending of the contained image tiles. We introduce HISTOBREAST, an extensive collection of brightfield microscopy images that we collected in a principled manner under different acquisition conditions on Haematoxylin - Eosin (H&E) stained breast tissue. HISTOBREAST is comprised of neighbour image tiles and ensemble of mosaics composed from different combinations of the available image tiles, exhibiting progressively degraded quality levels. HISTOBREAST can be used to benchmark image processing and computer vision techniques with respect to their robustness to image modifications specific to brightfield microscopy of H&E stained tissues. Furthermore, HISTOBREAST can serve in the development of new image processing methods, with the purpose of ensuring robustness to typical image artefacts that raise interpretation problems for expert histopathologists and affect the results of computerized image analysis.


Assuntos
Mama/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Microscopia/métodos , Amarelo de Eosina-(YS) , Feminino , Hematoxilina , Humanos , Software
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...