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Active life monitoring via chemosensitive sensors could hold promise for enhancing athlete monitoring, training optimization, and performance in athletes. The present work investigates a resistive flex sensor (RFS) in the guise of a chemical sensor. Its carbon 'texture' has shown to be sensitive to CO2, O2, and RH changes; moreover, different bending conditions can modulate its sensitivity and selectivity for these gases and vapors. A three-step feasibility study is presented including: design and fabrication of the electronic read-out and control; calibration of the sensors to CO2, O2 and RH; and a morphological study of the material when interacting with the gas and vapor molecules. The 0.1 mm-1 curvature performs best among the tested configurations. It shows a linear response curve for each gas, the ranges of concentrations are adequate, and the sensitivity is good for all gases. The curvature can be modulated during data acquisition to tailor the sensitivity and selectivity for a specific gas. In particular, good results have been obtained with a curvature of 0.1 mm-1. For O2 in the range of 20-70%, the sensor has a sensitivity of 0.7 mV/%. For CO2 in the range of 4-80%, the sensitivity is 3.7 mV/%, and for RH the sensitivity is 33 mV/%. Additionally, a working principle, based on observation via scanning electron microscopy, has been proposed to explain the chemical sensing potential of this sensor. Bending seems to enlarge the cracks present in the RFS coverage; this change accounts for the altered selectivity depending on the sensor's curvature. Further studies are needed to confirm result's reliability and the correctness of the interpretation.
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Medicina Esportiva , Medicina Esportiva/métodos , Calibragem , Humanos , Desenho de Equipamento , Dióxido de Carbono/análise , Dióxido de Carbono/química , Oxigênio/química , Oxigênio/análise , Técnicas Biossensoriais/métodosRESUMO
Invasive intraneural electrodes can control advanced neural-interfaced prostheses in human amputees. Nevertheless, in chronic implants, the progressive formation of a fibrotic capsule can gradually isolate the electrode surface from the surrounding tissue leading to loss of functionality. This is due to a nonspecific inflammatory response called foreign-body reaction (FBR). The commonly used poly(ethylene glycol) (PEG)-based low-fouling coatings of implantable devices can be easily encapsulated and are susceptible to oxidative damage in long-term in vivo applications. Recently, sulfobetaine-based zwitterionic hydrogels have emerged as an important class of robust ultra-low fouling biomaterials, holding great potential to mitigate FBR. The aim of this proof-of-principle in vitro work was to assess whether the organic zwitterionic-poly(sulfobetaine methacrylate) [poly(SBMA)]-hydrogel could be a suitable coating for Polyimide (PI)-based intraneural electrodes to reduce FBR. We first synthesized and analyzed the hydrogel through a mechanical characterization (i.e., Young's modulus). Then, we demonstrated reduced adhesion and activation of fibrogenic and pro-inflammatory cells (i.e., human myofibroblasts and macrophages) on the hydrogel compared with PEG-coated and polystyrene surfaces using cell viability assays, confocal fluorescence microscopy and high-content analysis of oxidative stress production. Interestingly, we successfully coated PI surfaces with a thin film of the hydrogel through covalent bond and demonstrated its high hydrophilicity via water contact angle measurement. Importantly, we showed the long-term release of an anti-fibrotic drug (i.e., Everolimus) from the hydrogel. Because of the low stiffness, biocompatibility, high hydration and ultra-low fouling characteristics, our zwitterionic hydrogel could be envisioned as long-term diffusion-based delivery system for slow and controlled anti-inflammatory and anti-fibrotic drug release in vivo.
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Reação a Corpo Estranho , Hidrogéis , Eletrodos , Reação a Corpo Estranho/prevenção & controle , Humanos , Hidrogéis/química , Metacrilatos/química , Polietilenoglicóis/químicaRESUMO
Organs-on-chip (OoCs) are catching on as a promising and valuable alternative to animal models, in line with the 3Rs initiative. OoCs enable the creation of three-dimensional (3D) tissue microenvironments with physiological and pathological relevance at unparalleled precision and complexity, offering new opportunities to model human diseases and to test the potential therapeutic effect of drugs, while overcoming the limited predictive accuracy of conventional 2D culture systems. Here, we present a liver-on-a-chip model to investigate the effects of two naturally occurring polyphenols, namely quercetin and hydroxytyrosol, on nonalcoholic fatty liver disease (NAFLD) using a high-content analysis readout methodology. NAFLD is currently the most common form of chronic liver disease; however, its complex pathogenesis is still far from being elucidated, and no definitive treatment has been established so far. In our experiments, we observed that both polyphenols seem to restrain the progression of the free fatty acid-induced hepatocellular steatosis, showing a cytoprotective effect due to their antioxidant and lipid-lowering properties. In conclusion, the findings of the present work could guide novel strategies to contrast the onset and progression of NAFLD.
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Dispositivos Lab-On-A-Chip , Fígado/metabolismo , Modelos Biológicos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Álcool Feniletílico/análogos & derivados , Quercetina/farmacologia , Células Hep G2 , Humanos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Álcool Feniletílico/farmacologiaRESUMO
Cancer stem cells (CSCs) are a subpopulation with the properties of extensive self-renewal, capability to generate differentiated cancer cells and resistance to therapies. We have previously shown that malignant pleural effusions (MPEs) from patients with non-small-cell lung cancer (NSCLC) represent a valuable source of cancer cells that can be grown as three-dimensional (3D) spheroids enriched for stem-like features, which depend on the activation of the Yes-associated protein-transcriptional coactivator with PDZ-binding motif (YAP-TAZ)/Wnt-ßcatenin/stearoyl-CoA desaturase 1 (SCD1) axis. Here, we describe a novel support, called CytoMatrix, for the characterization of limited amounts of cancer cells isolated from MPEs of patients with NSCLC. Our results show that this synthetic matrix allows an easy and fast characterization of several epithelial cellular markers. The use of CytoMatrix to study CSCs subpopulation confirms that SCD1 protein expression is enhanced in 3D spheroids when compared with 2D adherent cell cultures. YAP/TAZ nuclear-cytoplasmic distribution analysed by CytoMatrix in 3D spheroids is highly heterogeneous and faithfully reproduces what is observed in tumour biopsies. Our results confirm and extend the robustness of our workflow for the isolation and phenotypic characterization of primary cancer cells derived from the lung MPEs and underscore the role of SCD1.
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Citodiagnóstico/métodos , Neoplasias Pulmonares/patologia , Células-Tronco Neoplásicas/patologia , Derrame Pleural Maligno/patologia , Idoso , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Técnicas de Cultura de Células/métodos , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Feminino , Humanos , Pulmão/metabolismo , Pulmão/patologia , Neoplasias Pulmonares/metabolismo , Masculino , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/metabolismo , Derrame Pleural Maligno/metabolismo , Esferoides Celulares/metabolismo , Esferoides Celulares/patologia , Estearoil-CoA Dessaturase/metabolismo , Fatores de Transcrição/metabolismo , Células Tumorais CultivadasRESUMO
The increased frequency of thyroid nodules is paralleled by the rise of thyroid cancer diagnosis. To define the nature of most thyroid nodules, fine needle aspiration (FNA) followed by cytological evaluation is considered the method of choice. About 20% of FNA biopsies on thyroid nodules, however, show indeterminate cytological features and may require diagnostic surgery. Several immunocytochemical and molecular markers have been proposed to improve classification of thyroid nodules, but these tests require adequate cell amount and cytological paraffin inclusion. Polymeric matrices were recently proposed for the collection of cells for diagnostic purposes. In this study, we evaluated the diagnostic use of a new matrix (CytoMatrix). Morphological, molecular and immunohistochemical investigations were carried out on 23 FNA samples included in CytoMatrix and compared with data obtained from the definitive histology of surgical samples. Our results showed that CytoMatrix is suitable to capture and preserve the cellularity of the samples harvested by FNA and that its paraffin sections mimic the morphology of those obtained from real histological tissue. Immunohistochemistry on CytoMatrix samples was consistent with the immunophenotypical profile of the corresponding histological surgical specimens. Mutational analysis of the BRAF (V600E) gene performed on CytoMatrix inclusions and paired surgical tissue matched in all but one cases while matrix immunohistochemistry identified 91.6% of BRAF mutated samples. In conclusion, we suggest that CytoMatrix could be a reliable tool to overcome the current limits of traditional collection methods for the study of thyroid cytology, thereby improving their reliability for a conclusive diagnostic interpretation.
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Tendinopathies negatively affect the life quality of millions of people in occupational and athletic settings, as well as the general population. Tendon healing is a slow process, often with insufficient results to restore complete endurance and functionality of the tissue. Tissue engineering, using tendon progenitors, artificial matrices and bioreactors for mechanical stimulation, could be an important approach for treating rips, fraying and tissue rupture. In our work, C3H10T1/2 murine fibroblast cell line was exposed to a combination of stimuli: a biochemical stimulus provided by Transforming Growth Factor Beta (TGF-ß) and Ascorbic Acid (AA); a three-dimensional environment represented by PEGylated-Fibrinogen (PEG-Fibrinogen) biomimetic matrix; and a mechanical induction exploiting a custom bioreactor applying uniaxial stretching. In vitro analyses by immunofluorescence and mechanical testing revealed that the proposed combined approach favours the organization of a three-dimensional tissue-like structure promoting a remarkable arrangement of the cells and the neo-extracellular matrix, reflecting into enhanced mechanical strength. The proposed method represents a novel approach for tendon tissue engineering, demonstrating how the combined effect of biochemical and mechanical stimuli ameliorates biological and mechanical properties of the artificial tissue compared to those obtained with single inducement.
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Ácido Ascórbico/farmacologia , Fibroblastos/efeitos dos fármacos , Engenharia Tecidual/métodos , Fator de Crescimento Transformador beta/farmacologia , Animais , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Reatores Biológicos , Técnicas de Cultura de Células , Linhagem Celular , Matriz Extracelular/química , Fibrinogênio/química , Fibrinogênio/farmacologia , Fibroblastos/citologia , Fibroblastos/metabolismo , Mecanotransdução Celular , Camundongos , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Estresse Mecânico , Tendões/citologia , Tendões/efeitos dos fármacos , Tendões/crescimento & desenvolvimento , Tendões/metabolismo , Alicerces TeciduaisRESUMO
Cardiovascular aging is a physiological process affecting all components of the heart. Despite the interest and experimental effort lavished on aging of cardiac cells, increasing evidence is pointing at the pivotal role of extracellular matrix (ECM) in cardiac aging. Structural and molecular changes in ECM composition during aging are at the root of significant functional modifications at the level of cardiac valve apparatus. Indeed, calcification or myxomatous degeneration of cardiac valves and their functional impairment can all be explained in light of age-related ECM alterations and the reciprocal interplay between altered ECM and cellular elements populating the leaflet, namely valvular interstitial cells and valvular endothelial cells, is additionally affecting valve function with striking reflexes on the clinical scenario. The initial experimental findings on this argument are underlining the need for a more comprehensive understanding on the biological mechanisms underlying ECM aging and remodeling as potentially constituting a pharmacological therapeutic target or a basis to improve existing prosthetic devices and treatment options. Given the lack of systematic knowledge on this topic, this review will focus on the ECM changes that occur during aging and on their clinical translational relevance and implications in the bedside scenario.
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Envelhecimento/fisiologia , Matriz Extracelular/fisiologia , Valvas Cardíacas/fisiologia , Animais , HumanosRESUMO
PURPOSE: The present study evaluated the presence of stem cells in hamstring tendons from adult subjects of different ages. The aim was to isolate, characterize and expand these cells in vitro, and to evaluate whether cell activities are influenced by age. METHODS: Tendon stem cells (TSCs) were isolated through magnetic sorting from the hamstring tendons of six patients. TSC percentage, morphology and clonogenic potential were evaluated, as well as the expression of specific surface markers. TSC multi-potency was also investigated as a function of age, and quantitative polimerase chain reaction was used to evaluate gene expression of TSCs cultured in suitable differentiating media. RESULTS: The presence of easily harvestable stem cell population within adult human hamstring tendons was demonstrated. These cells exhibit features such as clonogenicity, multi-potency and mesenchymal stem cells markers expression. The age-related variations in human TSCs affect the number of isolated cells and their self-renewal potential, while multi-potency assays are not influenced by tendon ageing, even though cells from younger individuals expressed higher levels of osteogenic and adipogenic genes, while chondrogenic genes were highly expressed in cells from older individuals. CONCLUSIONS: These results may open new opportunities to study TSCs to better understand tendon physiology, healing and pathological processes such as tendinopathy and degenerative age-related changes opening new frontiers in the management of tendinopathy and tendon ruptures.
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Células-Tronco/citologia , Tendões/citologia , Adulto , Células Cultivadas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Células-Tronco/fisiologia , Tendões/fisiologia , Adulto JovemRESUMO
We investigate for the first time the compatibility of nanovials with microfluidic impedance cytometry (MIC). Nanovials are suspendable crescent-shaped single-cell microcarriers that enable specific cell adhesion, the creation of compartments for undisturbed cell growth and secretion, as well as protection against wall shear stress. MIC is a label-free single-cell technique that characterizes flowing cells based on their electrical fingerprints and it is especially targeted to cells that are naturally in suspension. Combining nanovial technology with MIC is intriguing as it would represent a robust framework for the electrical analysis of single adherent cells at high throughput. Here, as a proof-of-concept, we report the MIC analysis of mesenchymal stromal cells loaded in nanovials. The electrical analysis is supported by numerical simulations and validated by means of optical analysis. We demonstrate that the electrical diameter can discriminate among free cells, empty nanovials, cell-loaded nanovials, and clusters, thus grounding the foundation for the use of nanovials in MIC. Furthermore, we investigate the potentiality of MIC to assess the electrical phenotype of cells loaded in nanovials and we draw directions for future studies.
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Células-Tronco Mesenquimais , Técnicas Analíticas Microfluídicas , Análise de Célula Única , Células-Tronco Mesenquimais/citologia , Análise de Célula Única/instrumentação , Humanos , Técnicas Analíticas Microfluídicas/instrumentação , Impedância Elétrica , Nanoestruturas/química , Citometria de Fluxo/instrumentaçãoRESUMO
Hyaluronic acid (HA) based nanogels showed effective intracellular delivery efficacy for anti-cancer and anti-inflammatory drugs, characterized by their ability targeting relevant cell receptors. In the present study, we demonstrate the ability of hyaluronic acid-polyethyleneimine (HA-PEI) nanogels as a promising dual-functional interfacial active for intra-articular injection to intervene arthritis. Nanomechanical measurements on both model substrates and human cartilage samples confirm that the HA-PEI nanogels can significantly improve interfacial lubrication, in comparison to HA molecules, or silica-based nanoparticles. We show that the Coefficient of Friction significantly decreases with a decreasing nanogel size. The exceptional lubricating performance, coupled with the proven drug delivery capability, evidences the great potential of nanoscopic hydrogels for early-stage arthritis treatment. The flexibility in choosing the chemical nature, molecular architecture, and structural characteristics of nanogels makes it possible to modulate both drug delivery kinetics and interfacial lubrication, thus representing an innovative approach to treat degenerative joint diseases.
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Ácido Hialurônico , Polietilenoimina , Ácido Hialurônico/química , Ácido Hialurônico/administração & dosagem , Injeções Intra-Articulares/métodos , Humanos , Polietilenoimina/química , Nanopartículas/química , Nanopartículas/administração & dosagem , Nanogéis/química , Animais , Sistemas de Liberação de Medicamentos/métodos , Hidrogéis/química , Cartilagem Articular/efeitos dos fármacos , Tamanho da PartículaRESUMO
Currently, one of the main drawbacks of using poly(ε-caprolactone) in the biomedical and pharmaceutical fields is represented by its low biodegradation rate. To overcome this limitation, electrospinning of PCL blended with a water-soluble poly(N-vinyl-2-pyrrolidone) was used to fabricate scaffolds with tunable fiber surface morphology and controllable degradation rates. Electrospun scaffolds revealed a highly immiscible blend state. The incorporated PVP phase was dispersed as inclusions within the electrospun fibers, and then easily extracted by immersing them in cell culture medium, exhibiting nanoporosity on the fiber surface. As a striking result, nanoporosity facilitated not only fiber biodegradation rates, but also improved cell attachment and spreading on the blend electrospun scaffolds. The present findings demonstrate that simultaneous electrospinning technique for PCL with water-soluble PVP provides important insights for successful tuning biodegradation rate for the PCL electrospun scaffolds but not limited to expand other high valuable biocompatible polymers for the future biomedical applications, ranging from tissue regeneration to controlled drug delivery.
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Implantes Absorvíveis , Caprolactama/química , Eletroquímica/métodos , Pirrolidinonas/química , Células-Tronco/citologia , Engenharia Tecidual/instrumentação , Alicerces Teciduais , Animais , Materiais Biocompatíveis/síntese química , Adesão Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Misturas Complexas/síntese química , Análise de Falha de Equipamento , Teste de Materiais , Camundongos , Desenho de Prótese , RotaçãoRESUMO
PURPOSE: Annulus fibrosus (AF) tissue engineering is gathering increasing interest for the development of strategies to reduce recurrent disc herniation (DH) rate and to increase the effectiveness of intervertebral disc regeneration strategies. This study evaluates the use of a bioactive microfibrous poly(L-lactide) scaffold releasing Transforming Growth Factor (TGF)-ß1 (PLLA/TGF) for the repair and regeneration of damaged AF. METHODS: The scaffold was synthesized by electrospinning, with a direct incorporation of TGF-ß1 into the polymeric solution, and characterized in terms of morphology and drug release profile. Biological evaluation was performed with bovine AF cells (AFCs) that were cultured on the scaffold up to 3 weeks to quantitatively assess glycosaminoglycans and total collagen production, using bare electrospun PLLA as a control. Histological evaluation was performed to determine the thickness of the deposited neo-ECM. RESULTS: Results demonstrated that AFCs cultured on PLLA/TGF deposited a significantly greater amount of glycosaminoglycans and total collagen than the control, with higher neo-ECM thickness. CONCLUSIONS: PLLA/TGF scaffold induced an anabolic stimulus on AFCs, mimicking the ECM three-dimensional environment of AF tissue. This bioactive scaffold showed encouraging results that allow envisaging an application for AF tissue engineering strategies and AF repair after discectomy for the prevention of recurrent DH.
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Deslocamento do Disco Intervertebral/patologia , Deslocamento do Disco Intervertebral/terapia , Disco Intervertebral/patologia , Disco Intervertebral/fisiologia , Regeneração/fisiologia , Engenharia Tecidual/métodos , Alicerces Teciduais , Animais , Bovinos , Sobrevivência Celular , Células Cultivadas , Colágeno/metabolismo , Matriz Extracelular/metabolismo , Glicosaminoglicanos/metabolismo , Modelos Animais , Poliésteres/metabolismo , Fator de Crescimento Transformador beta1/metabolismoRESUMO
Conventional batch syntheses of polymer-based nanoparticles show considerable shortcomings in terms of scarce control over nanomaterials morphology and limited lot-to-lot reproducibility. Droplet-based microfluidics represents a valuable strategy to overcome these constraints, exploiting the formation of nanoparticles within discrete microdroplets. In this work, we synthesized nanogels (NGs) composed of hyaluronic acid and polyethyleneimine using a microfluidic flow-focusing device endowed with a pressure-driven micro-actuator. The actuator achieves real-time modulation of the junction orifice width, thereby regulating the microdroplet diameter and, as a result, the NG size. Acting on process parameters, NG hydrodynamic diameter could be tuned in the range 92-190 nm while preserving an extremely low polydispersity (0.015); those values are hardly achievable in batch syntheses and underline the strength of our toolbox for the continuous in-flow synthesis of nanocarriers. Furthermore, NGs were validated in vitro as a drug delivery system in a representative case study still lacking an effective therapeutic treatment: ovarian cancer. Using doxorubicin as a chemotherapeutic agent, we show that NG-mediated release of the drug results in an enhanced antiblastic effect vs. the non-encapsulated administration route even at sublethal dosages, highlighting the wide applicability of our microfluidics-enabled nanomaterials in healthcare scenarios.
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Nanopartículas , Nanoestruturas , Sistemas de Liberação de Medicamentos , Microfluídica/métodos , Nanogéis , Reprodutibilidade dos TestesRESUMO
Myocardial infarction and its consequences represent one of the most demanding challenges in cell therapy and regenerative medicine. Transfer of skeletal myoblasts into decompensated hearts has been performed through intramyocardial injection. However, the achievements of both cardiomyocyte differentiation and precise integration of the injected cells into the myocardial wall, in order to augment synchronized contractility and avoid potentially life-threatening alterations in the electrical conduction of the heart, still remain a major target to be pursued. Recently, granulocytes colony-stimulating factor (G-CSF) fuelled the interest of researchers for its direct effect on cardiomyocytes, inhibiting both apoptosis and remodelling in the failing heart and protecting from ventricular arrhythmias through the up-regulation of connexin 43 (Cx43). We propose a tissue engineering approach concerning the fabrication of an electrospun cardiac graft functionalized with G-CSF, in order to provide the correct signalling sequence to orientate myoblast differentiation and exert important systemic and local effects, positively modulating the infarction microenvironment. Poly-(L-lactide) electrospun scaffolds were seeded with C2C12 murine skeletal myoblast for 48 hrs. Biological assays demonstrated the induction of Cx43 expression along with morphostructural changes resulting in cell elongation and appearance of cellular junctions resembling the usual cardiomyocyte arrangement at the ultrastructural level. The possibility of fabricating extracellular matrix-mimicking scaffolds able to promote myoblast pre-commitment towards myocardiocyte lineage and mitigate the hazardous environment of the damaged myocardium represents an interesting strategy in cardiac tissue engineering.
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Diferenciação Celular , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Mioblastos Esqueléticos/transplante , Transplante de Células-Tronco/métodos , Células-Tronco/metabolismo , Animais , Proliferação de Células , Conexina 43/biossíntese , Conexina 43/genética , Fator Estimulador de Colônias de Granulócitos/metabolismo , Camundongos , Microscopia Eletrônica de Transmissão , Infarto do Miocárdio/terapia , Poliésteres/uso terapêutico , Células-Tronco/citologia , Engenharia Tecidual , Alicerces TeciduaisRESUMO
Nanogels represent an innovative platform for tunable drug release and targeted therapy in several biomedical applications, ranging from cancer to neurological disorders. The design of these nanocarriers is a pivotal topic investigated by the researchers over the years, with the aim to optimize the procedures and provide advanced nanomaterials. Chemical reactions, physical interactions and the developments of engineered devices are the three main areas explored to overcome the shortcomings of the traditional nanofabrication approaches. This review proposes a focus on the current techniques used in nanogel design, highlighting the upgrades in physico-chemical methodologies, microfluidics and 3D printing. Polymers and biomolecules can be combined to produce ad hoc nanonetworks according to the final curative aims, preserving the criteria of biocompatibility and biodegradability. Controlled polymerization, interfacial reactions, sol-gel transition, manipulation of the fluids at the nanoscale, lab-on-a-chip technology and 3D printing are the leading strategies to lean on in the next future and offer new solutions to the critical healthcare scenarios.
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Face masks help to limit transmission of infectious diseases entering through the nose and mouth. Beyond reprocessing and decontamination, antimicrobial treatments could extend the lifetime of face masks whilst also further reducing the chance of disease transmission. Here, we review the efficacy of treatments pertaining antimicrobial properties to medical face masks, filtering facepiece respirators and non-medical face masks. Searching databases identified 2113 studies after de-duplication. A total of 17 relevant studies were included in the qualitative synthesis. Risk of bias was found to be moderate or low in all cases. Sixteen articles demonstrated success in avoiding proliferation (if not elimination) of viruses and/or bacteria. In terms of methodology, no two articles employed identical approaches to efficacy testing. Our findings highlight that antimicrobial treatment is a promising route to extending the life and improving the safety of face masks. In order to reach significant achievements, shared and precise methodology and reporting is needed.
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The synthesis of graphene-based materials has attracted considerable attention in drug delivery strategies. Indeed, the conductivity and mechanical stability of graphene have been investigated for controlled and tunable drug release via electric or mechanical stimuli. However, the design of a thermo-sensitive scaffold using pristine graphene (without distortions related to the oxidation processes) has not been deeply investigated yet, although it may represent a promising approach for several therapeutic treatments. Here, few-layer graphene was used as a nanofiller in a hydrogel system with a thermally tunable drug release profile. In particular, varying the temperature (25 °C, 37 °C and 44 °C), responsive drug releases were noticed and hypothesized depending on the formation and perturbation of π-π interactions involving graphene, the polymeric matrix and the model drug (diclofenac). As a result, these hybrid hydrogels show a potential application as thermally triggered drug release systems in several healthcare scenarios.
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Grafite , Hidrogéis , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Condutividade Elétrica , TemperaturaRESUMO
Nanomaterials hold promise as a straightforward approach for enhancing the performance of bioactive compounds in several healthcare scenarios. Indeed, nanoencapsulation represents a valuable strategy to preserve the bioactives, maximizing their bioavailability. Here, a nanoencapsulation strategy for the treatment of nonalcoholic fatty liver disease (NAFLD) is presented. NAFLD represents the most common chronic liver disease in Western societies, and still lacks an effective therapy. Hydroxytyrosol (HT), a naturally occurring polyphenol, has been shown to protect against hepatic steatosis through its lipid-lowering, antioxidant and anti-inflammatory activities. However, the efficient delivery of HT to hepatocytes remains a crucial aspect: the design of smart nanogels appears as a promising tool to promote its intracellular uptake. In this paper, we disclose the synthesis of nanogel systems based on polyethylene glycol and polyethyleneimine which have been tested in an in vitro model of hepatic steatosis at two different concentrations (0.1 mg/mL and 0.5 mg/mL), taking advantage of high-content analysis tools. The proposed HT-loaded nanoscaffolds are non-toxic to cells, and their administration showed a significant decrease in the intracellular triglyceride levels, restoring cell viability and outperforming the results achievable with HT in its non-encapsulated form. Moreover, nanogels do not induce oxidative stress, thus demonstrating their biosafety. Overall, the formulated nanogel system achieves superior performance compared to conventional drug administration routes and hence represents a promising strategy for the management of NAFLD.
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Hepatopatia Gordurosa não Alcoólica , Álcool Feniletílico , Humanos , Nanogéis , Estresse Oxidativo , Álcool Feniletílico/análogos & derivados , Álcool Feniletílico/farmacologiaRESUMO
Electrospinning of biopolymeric scaffolds is a new and effective approach for creating replacement tissues to repair defects and/or damaged tissues with direct clinical application. However, many hurdles and technical concerns regarding biological issues, such as cell retention and the ability to grow, still need to be overcome to gain full access to the clinical arena. Interaction with the host human tissues, immunogenicity, pathogen transmission as well as production costs, technical expertise, and good manufacturing and laboratory practice requirements call for careful consideration when aiming at the production of a material that is available off-the-shelf, to be used immediately in operative settings. The issue of sterilization is one of the most important steps for the clinical application of these scaffolds. Nevertheless, relatively few studies have been performed to systematically investigate how sterilization treatments may affect the properties of electrospun polymers for tissue engineering. This paper presents the results of a comparative study of different sterilization techniques applied to an electrospun poly-L-lactide scaffold: soaking in absolute ethanol, dry oven and autoclave treatments, UV irradiation, and hydrogen peroxide gas plasma treatment. Morphological and chemical characterization was coupled with microbiological sterility assay to validate the examined sterilization techniques in terms of effectiveness and modifications to the scaffold. The results of this study reveal that UV irradiation and hydrogen peroxide gas plasma are the most effective sterilization techniques, as they ensure sterility of the electrospun scaffolds without affecting their chemical and morphological features.
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Implantes Absorvíveis/normas , Poliésteres/normas , Alicerces Teciduais , Etanol , Temperatura Alta , Humanos , Peróxido de Hidrogênio , Poliésteres/química , Espectroscopia de Infravermelho com Transformada de Fourier , Esterilização/instrumentação , Esterilização/métodos , Engenharia Tecidual/métodos , Engenharia Tecidual/normas , Alicerces Teciduais/normas , Raios UltravioletaRESUMO
A thermoresponsive Pluronic/alginate semisynthetic hydrogel is used to bioprint 3D hepatic constructs, with the aim to investigate liver-specific metabolic activity of the 3D constructs compared to traditional 2D adherent cultures. The bioprinting method relies on a bioinert hydrogel and is characterized by high-shape fidelity, mild depositing conditions and easily controllable gelation mechanism. Furthermore, the dissolution of the sacrificial Pluronic templating agent significantly ameliorates the diffusive properties of the printed hydrogel. The present findings demonstrate high viability and liver-specific metabolic activity, as assessed by synthesis of urea, albumin, and expression levels of the detoxifying CYP1A2 enzyme of cells embedded in the 3D hydrogel system. A markedly increased sensitivity to a well-known hepatotoxic drug (acetaminophen) is observed for cells in 3D constructs compared to 2D cultures. Therefore, the 3D model developed herein may represent an in vitro alternative to animal models for investigating drug-induced hepatotoxicity.