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The magnitude and breadth of the neutralizing antibody response against variants of concern following natural infection would provide valuable insights regarding the immune response induced by severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) infection. Herein, 25 patients were followed at 30 ±7 (Visit 1), 90± 15 (Visit 2), and 180 ± 15 (Visit 3) days post symptom onset (PSO). The neutralization titers against both Wuhan-Hu-1 (WT) and Delta variant were analyzed in parallel along with anti-Spike antibodies (anti-S1/S2 immunoglobulin G [IgG]). The median values of half-maximal neutralization titer (NT50 ) for the WT and Delta variants decreased by 75.8% and 82.2% at Visit 2 and by 85.4% and 81.4% at Visit 3, respectively. At Visit 1, the correlation between the anti-S1/S2 IgG and Nabs titers for the Delta variant was moderate for WT (r = 0.58) and weak for the Delta variant (r = 0.39). However, the correlation coefficient consistently remained above 0.7, with a very strong correlation at Visit 3 for both WT and Delta variants (r = 0.81). The dynamics of anti-S1/S2 IgG antibodies, NT50 , and cross-neutralization index correlated at different time points PSO. Longitudinal analysis of the cross-neutralization capacity of immune sera will inform upon the durability of the immune response against SARS CoV-2 variants.
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COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Anticorpos Neutralizantes , Imunoglobulina G , Anticorpos Antivirais , Glicoproteína da Espícula de Coronavírus/genéticaRESUMO
BACKGROUND: National palliative care plans depend upon stakeholder engagement to succeed. Assessing the capability, interest, and knowledge of stakeholders is a crucial step in the implementation of public health initiatives, as recommended by the World Health Organisation. However, utilising stakeholder analysis is a strategy underused in public palliative care. OBJECTIVE: To conduct a stakeholder analysis characterising a diverse group of stakeholders involved in implementing a national palliative care plan in three rural regions of an upper-middle-income country. METHODS: A descriptive cross-sectional study design, complemented by a quantitative stakeholder analysis approach, was executed through a survey designed to gauge stakeholders' levels of interest and capability in relation to five fundamental dimensions of public palliative care: provision of services, accessibility of essential medicines, palliative care education, financial support, and palliative care vitality. Stakeholders were categorised as promoters (high-power, high-interest), latent (high-power, low-interest), advocates (low-power, high-interest), and indifferent (low-power and low-interest). Stakeholder self-perceived category and knowledge level were also assessed. RESULTS: Among the 65 surveyed stakeholders, 19 were categorised as promoters, 34 as advocates, 9 as latent, and 3 as indifferent. Stakeholders' self-perception of their category did not align with the results of the quantitative analysis. When evaluated by region and palliative care dimensions the distribution of stakeholders was nonuniform. Palliative care funding was the dimension with the highest number of stakeholders categorised as indifferent, and the lowest percentage of promoters. Stakeholders categorised as promoters consistently reported a low level of knowledge, regardless of the dimension, region, or their level of interest. CONCLUSIONS: Assessing the capability, interest, and knowledge of stakeholders is a crucial step when implementing public health initiatives in palliative care. It allows for a data-driven decision-making process on how to delegate responsibilities, administer financial resources, and establish governance boards that remain engaged and work efficiently.
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Cuidados Paliativos , Participação dos Interessados , Humanos , Cuidados Paliativos/métodos , Cuidados Paliativos/normas , Estudos Transversais , Inquéritos e Questionários , Masculino , Feminino , Adulto , Pessoa de Meia-IdadeRESUMO
Designing and obtaining new synthetic smart biointerfaces with specific and controlled characteristics relevant for applications in biomedical and bioengineering domains represents one of the main challenges in these fields. In this work, Matrix-Assisted Pulsed Laser Evaporation (MAPLE) is used to obtain synthetic biointerfaces of poly(N-isopropyl acrylamide-butyl acrylate) p(NIPAM-BA) copolymer with different characteristics (i.e., roughness, porosity, wettability), and their effect on normal HEK 293 T and murine melanoma B16-F1 cells is studied. For this, the influence of various solvents (chloroform, dimethylsulfoxide, water) and fluence variation (250-450 mJ/cm2) on the morphological, roughness, wettability, and physico-chemical characteristics of the coatings are evaluated by atomic force microscopy, scanning electron microscopy, contact angle measurements, Fourier-transform-IR spectroscopy, and X-ray photoelectron spectroscopy. Coatings obtained by the spin coating method are used for reference. No significant alteration in the chemistry of the surfaces is observed for the coatings obtained by both methods. All p(NIPAM-BA) coatings show hydrophilic character, with the exception of those obtained with chloroform at 250 mJ/cm2. The surface morphology is shown to depend on both solvent type and laser fluence and it ranges from smooth surfaces to rough and porous ones. Physico-chemical and biological analysis reveal that the MAPLE deposition method with fluences of 350-450 mJ/cm2 when using DMSO solvent is more appropriate for bioengineering applications due to the surface characteristics (i.e., pore presence) and to the good compatibility with normal cells and cytotoxicity against melanoma cells.
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Clorofórmio , Melanoma , Acrilamidas , Acrilatos , Animais , Dimetil Sulfóxido , Células HEK293 , Humanos , Camundongos , Polímeros/química , Polímeros/farmacologia , Solventes , Propriedades de SuperfícieRESUMO
Microscopy techniques are often exploited by virologists to investigate molecular details of critical steps in viruses' life cycles such as host cell recognition and entry, genome replication, intracellular trafficking, and release of mature virions. Fluorescence microscopy is the most attractive tool employed to detect intracellular localizations of various stages of the viral infection and monitor the pathogen-host interactions associated with them. Super-resolution microscopy techniques have overcome the technical limitations of conventional microscopy and offered new exciting insights into the formation and trafficking of human viruses. In addition, the development of state-of-the art electron microscopy techniques has become particularly important in studying virus morphogenesis by revealing ground-braking ultrastructural details of this process. This review provides recent advances in human viruses imaging in both, in vitro cell culture systems and in vivo, in the animal models recently developed. The newly available imaging technologies bring a major contribution to our understanding of virus pathogenesis and will become an important tool in early diagnosis of viral infection and the development of novel therapeutics to combat the disease.
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Microscopia Eletrônica/métodos , Microscopia de Fluorescência/métodos , Viroses/diagnóstico por imagem , Viroses/diagnóstico , Vírus/patogenicidade , Animais , Modelos Animais de Doenças , Transferência Ressonante de Energia de Fluorescência/métodos , Interações Hospedeiro-Patógeno , Humanos , FotodegradaçãoRESUMO
Despite important progress toward deciphering human hepatitis B virus (HBV) entry into host cells, many aspects of the early steps of the life cycle remained completely obscure. Following endocytosis, HBV must travel through the complex network of the endocytic pathway to reach the cell nucleus and initiate replication. In addition to guiding the viral particles to the replication site, the endosomal vesicles may play a crucial role in infection, providing the appropriate environment for virus uncoating and nucleocapsid release. In this work, we investigated the trafficking of HBV particles internalized in permissive cells. Expression of key Rab proteins, involved in specific pathways leading to different intracellular locations, was modulated in HepaRG cells, using a stable and inducible short hairpin RNA (shRNA) expression system. The trafficking properties of the newly developed cells were demonstrated by confocal microscopy and flow cytometry using specific markers. The results showed that HBV infection strongly depends on Rab5 and Rab7 expression, indicating that HBV transport from early to mature endosomes is required for a step in the viral life cycle. This may involve reduction of disulfide bond-linked envelope proteins, as alteration of the redox potential of the endocytic pathway resulted in inhibition of infection. Subcellular fractionation of HBV-infected cells showed that viral particles are further transported to lysosomes. Intriguingly, infection was not dependent on the lysosomal activity, suggesting that trafficking to this compartment is a "dead-end" route. Together, these data add to our understanding of the HBV-host cell interactions controlling the early stages of infection.
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Endossomos/metabolismo , Vírus da Hepatite B/fisiologia , Hepatite B/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab5 de Ligação ao GTP/metabolismo , Linhagem Celular , Endossomos/virologia , Hepatite B/genética , Hepatite B/virologia , Vírus da Hepatite B/genética , Humanos , Lisossomos/metabolismo , Lisossomos/virologia , Proteínas rab de Ligação ao GTP/genética , Proteínas rab5 de Ligação ao GTP/genética , proteínas de unión al GTP Rab7RESUMO
In this work, antitumor compounds, lactoferrin [recombinant iron-free (Apo-rLf)], cisplatin (Cis) or their combination were embedded within a biodegradable polycaprolactone (PCL) polymer thin film, by a modified approach of a laser-based technique, matrix-assisted pulsed laser evaporation (MAPLE). The structural and morphological properties of the deposited hybrid films were analyzed by Fourier-transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). The in vitro effect on the cells' morphology and proliferation of murine melanoma B16-F10 cells was investigated and correlated with the films' surface chemistry and topography. Biological assays revealed decreased viability and proliferation, lower adherence, and morphological modifications in the case of melanoma cells cultured on both Apo-rLf and Cis thin films. The antitumor effect was enhanced by deposition of Apo-rLf with Cis within the same film. The unique capability of the new approach, based on MAPLE, to embed antitumor active factors within a biodegradable matrix for obtaining novel biodegradable hybrid platform with increased antitumor efficiency has been demonstrated.
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Anticarcinógenos/química , Materiais Revestidos Biocompatíveis/química , Poliésteres/química , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/química , Lactoferrina/química , Lasers , Camundongos , Microscopia de Força Atômica , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de SuperfícieRESUMO
In this study, hybrid bio-nanoporous peptides loaded onto poly(N-isopropylacrylamide-co-butylacrylate) (pNIPAM-co-BA) coatings were designed and obtained via matrix-assisted pulsed laser evaporation (MAPLE) technique. The incorporation of cationic peptides magainin (MG) and melittin (Mel) and their combination was tailored to target synergistic anticancer and antibacterial activities with low toxicity on normal mammalian cells. Atomic force microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy as well as contact angle and surface energy measurements revealed the successful and functional incorporation of both the peptides within porous polymeric nanolayers as well as surface modifications (i.e. variation in the pore size diameter, surface roughness, and wettability) after Mel, MG or Mel-MG incorporation compared to pNIPAM-co-BA. In vitro testing revealed the impairment of biofilm formation on all the hybrid coatings while testing with S. aureus, E. coli and P. aeruginosa. Moreover, MG was shown to modulate the effect of Mel in the combined Mel-MG extract formulation released via pNIPAM-platforms, thus significantly reducing cancer cell proliferation through apoptosis/necrosis as revealed by flow cytometry analysis performed in vitro on HEK293T, A375, B16F1 and B16F10 cells. To the best of our knowledge, Mel-MG combination entrapped in the pNIPAM-co-BA copolymer has not yet been reported as a new promising candidate with anticancer and antibacterial properties for improved utility in the biomedical field. Mel-MG incorporation compared to pNIPAM-co-BA in in vitro testing revealed the impairment of biofilm formation in all the hybrid formulations.
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Lactoferrin (Lf) was shown to exhibit its antiviral activity at an early phase of viral infection and a mechanism whereby the protein interacts with host cell surface molecules has been suggested. In this study, human Lf (HLf) and seven HLf-derived synthetic peptides (HLP) corresponding to the N-terminal domain of the native protein (1-47 amino acids sequence) were assayed for their capacity to prevent hepatitis B virus (HBV) infection and replication using the HepaRG and HepG2.2.2.15 cell lines. Of the series tested, four peptides showed 40-75% inhibition of HBV infection in HepaRG cells, HLP1-23 , containing the GRRRR cationic cluster, being the most potent. Interestingly, this cluster is one of the two glycosaminoglycan binding sites of the native HLf involved in its antiviral activity; however, the mechanism of the HLP1-23 action was different from that of the full-length protein, the peptide inhibiting HBV infection when pre-incubated with the virus, while no effect was observed on the target cells. It is suggested that the cationic cluster is sufficient for the peptide to interact stably with negatively charged residues on the virion envelope, while the absence of the second glycosaminoglycan binding site prevents its efficient attachment to the cells. In conclusion, this peptide may constitute a non-toxic approach for potential clinical applications in inhibiting HBV entry by neutralizing the viral particles.
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Antivirais/farmacologia , Vírus da Hepatite B/efeitos dos fármacos , Lactoferrina/farmacologia , Fragmentos de Peptídeos/farmacologia , Linhagem Celular , Vírus da Hepatite B/fisiologia , Hepatócitos/virologia , Humanos , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacosRESUMO
In this study, we report on the synthesis of L-Cysteine (L-Cys)-coated magnetic iron oxide nanoparticles (NPs) loaded with doxorubicin (Dox). The Fe3O4-L-Cys-Dox NPs were extensively characterized for their compositional and morpho-structural features using EDS, SAED, XRD, FTIR and TEM. XPS, MÓ§ssbauer spectroscopy and SQUID measurements were also performed to determine the electronic and magnetic properties of the Fe3O4-L-Cys-Dox nanoparticles. Moreover, by means of a FO-SPR sensor, we evidenced and confirmed the binding of Dox to L-Cys. Biological tests on mouse (B16F10) and human (A375) metastatic melanoma cells evidenced the internalization of magnetic nanoparticles delivering Dox. Half maximum inhibitory concentration IC50 values of Fe3O4-L-Cys-Dox were determined for both cell lines: 4.26 µg/mL for A375 and 2.74 µg/mL for B16F10, as compared to 60.74 and 98.75 µg/mL, respectively, for unloaded controls. Incubation of cells with Fe3O4-L-Cys-Dox modulated MAPK signaling pathway activity 3 h post-treatment and produced cell cycle arrest and increased apoptosis by 48 h. We show that within the first 2 h of incubation in physiological (pH = 7.4) media, ~10-15 µM Dox/h was released from a 200 µg/mL Fe3O4-L-Cys-Dox solution, as compared to double upon incubation in citrate solution (pH = 3), which resembles acidic environment conditions. Our results highlight the potential of Fe3O4-L-Cys-Dox NPs as efficient drug delivery vehicles in melanoma therapy.
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Different cell types have been reported to internalize lactoferrin (Lf) by specific or nonspecific receptors. Our studies focused on the endocytic pathway of human Lf in macrophage-like THP-1 cells. Lactoferrin was found to be internalized by THP-1 cells differentiated with phorbol myristate acetate. Incubation of cells with chlorpromazine and dansylcadaverine, inhibitors of clathrin-dependent endocytosis, led to a 50% inhibition of Lf internalization compared with untreated cells. Bafilomycin A1 and NH(4)Cl treatment also resulted in 40%-60% inhibition, respectively, suggesting that the internalization of Lf may partly be mediated by acidic endosome-like organelles. Endocytic uptake of Lf was also cholesterol-dependent, as shown by methyl-ß-cyclodextrin or nystatin treatment of the cells prior to internalization. Partial colocalization of Lf and EEA-1, a marker specific for early endosomes, could be observed. Colocalization of Lf with a specific endoplasmic reticulum marker was also detected. Our results suggest that Lf is internalized mainly by the clathrin-dependent pathway in THP-1 cells and targets the ER. The physiological consequences of this intracellular trafficking will be the subject of future investigations.
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Endocitose , Lactoferrina/metabolismo , Macrófagos/metabolismo , Cloreto de Amônio/farmacologia , Cadaverina/análogos & derivados , Cadaverina/farmacologia , Linhagem Celular , Clorpromazina/farmacologia , Colesterol/fisiologia , Endocitose/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Endossomos/efeitos dos fármacos , Endossomos/metabolismo , Humanos , Macrolídeos/farmacologia , Macrófagos/efeitos dos fármacos , Microscopia de Fluorescência , Transporte Proteico/efeitos dos fármacosRESUMO
Nowadays, using polymers with specific characteristics to coat the surface of a device to prevent undesired biological responses can represent an optimal strategy for developing new and more efficient implants for biomedical applications. Among them, zwitterionic phosphorylcholine-based polymers are of interest due to their properties to resist cell and bacterial adhesion. In this work, the Matrix-Assisted Laser Evaporation (MAPLE) technique was investigated as a new approach for functionalising Polydimethylsiloxane (PDMS) surfaces with zwitterionic poly(2-Methacryloyloxyethyl-Phosphorylcholine) (pMPC) polymer. Evaluation of the physical-chemical properties of the new coatings revealed that the technique proposed has the advantage of achieving uniform and homogeneous stable moderate hydrophilic pMPC thin layers onto hydrophobic PDMS without any pre-treatment, therefore avoiding the major disadvantage of hydrophobicity recovery. The capacity of modified PDMS surfaces to reduce bacterial adhesion and biofilm formation was tested for Gram-positive bacteria, Staphylococcus aureus (S. aureus), and Gram-negative bacteria, Escherichia coli (E. coli). Cell adhesion, proliferation and morphology of human THP-1 differentiated macrophages and human normal CCD-1070Sk fibroblasts on the different surfaces were also assessed. Biological in vitro investigation revealed a significantly reduced adherence on PDMS-pMPC of both E. coli (from 29 × 10 6 to 3 × 102 CFU/mL) and S. aureus (from 29 × 106 to 3 × 102 CFU/mL) bacterial strains. Additionally, coated surfaces induced a significant inhibition of biofilm formation, an effect observed mainly for E. coli. Moreover, the pMPC coatings improved the capacity of PDMS to reduce the adhesion and proliferation of human macrophages by 50% and of human fibroblast by 40% compared to unmodified scaffold, circumventing undesired cell responses such as inflammation and fibrosis. All these highlighted the potential for the new PDMS-pMPC interfaces obtained by MAPLE to be used in the biomedical field to design new PDMS-based implants exhibiting long-term hydrophilic profile stability and better mitigating foreign body response and microbial infection.
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Osteoarthritis (OA) is a degenerative joint disease. An objective of the nanomedicine and drug delivery systems field is to design suitable pharmaceutical nanocarriers with controllable properties for drug delivery and site-specific targeting, in order to achieve greater efficacy and minimal toxicity, compared to the conventional drugs. The aim of this review is to present recent data on natural bioactive compounds with anti-inflammatory properties and efficacy in the treatment of OA, their formulation in lipid nanostructured carriers, mainly liposomes, as controlled release systems and the possibility to be intra-articularly (IA) administered. The literature regarding glycosaminoglycans, proteins, polyphenols and their ability to modify the cell response and mechanisms of action in different models of inflammation are reviewed. The advantages and limits of using lipid nanoformulations as drug delivery systems in OA treatment and the suitable route of administration are also discussed. Liposomes containing glycosaminoglycans presented good biocompatibility, lack of immune system activation, targeted delivery of bioactive compounds to the site of action, protection and efficiency of the encapsulated material, and prolonged duration of action, being highly recommended as controlled delivery systems in OA therapy through IA administration. Lipid nanoformulations of polyphenols were tested both in vivo and in vitro models that mimic OA conditions after IA or other routes of administration, recommending their clinical application.
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To modulate the biofunctionality of implantable medical devices commonly used in clinical practice, their surface modification with bioactive polymeric coatings is an attractive and successful emerging strategy. Biodegradable coatings based on poly(lactic acid-co-glycolic acid), PLGA, represent versatile and safe candidates for surface modification of implantable biomaterials and devices, providing additional tunable ability for topical delivery of desired therapeutic agents. In the present study, Ibuprofen-loaded PLGA coatings (PLGA/IBUP) were obtained by using the dip-coating and drop-casting combined protocol. The composite materials demonstrated long-term drug release under biologically simulated dynamic conditions. Reversible swelling phenomena of polymeric coatings occurred in the first two weeks of testing, accompanied by the gradual matrix degradation and slow release of the therapeutic agent. Irreversible degradation of PLGA coatings occurred after one month, due to copolymer's hydrolysis (evidenced by chemical and structural modifications). After 30 days of dynamic testing, the cumulative release of IBUP was ~250 µg/mL. Excellent cytocompatibility was revealed on human-derived macrophages, fibroblasts and keratinocytes. The results herein evidence the promising potential of PLGA/IBUP coatings to be used for surface modification of medical devices, such as metallic implants and wound dressings.
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A number of studies have reported the anti-tumoral activity of lactoferrin, a property mediated by a variety of mechanisms such as inhibitory effects on tumor cell growth, NK cell activation, and enhancement of apoptosis. Liposomes are known to be an efficient drug delivery system which can enhance the therapeutic potential of the encapsulated compounds. We have used positively charged liposomes composed of phosphatidylcholine (PC), dioleoylphosphatidylethanolamine (DOPE), cholesterol (Chol) and stearylamine (SA) (6:1:2:1 M ratio) as a carrier system for bovine iron-free Lf (ApoBLf), and compared the in vitro effect of free and liposome-entrapped ApoBLf on the growth and morphology of murine melanoma B16-F10 cells. Liposomal formulation of ApoBLf was found to enhance the capacity of the protein to inhibit the cell proliferation by affecting cell cycle progression. The effect appeared to be due to the capacity of liposomes to increase the uptake of the protein and its accumulation into cells and probably to protect it from degradation, as revealed by fluorescence microscopy and flow cytometry. Our results demonstrate the ability of liposomes to improve the anti-tumor activity of Lf and suggest that liposomal protein may have a potential therapeutic use in the prevention and/or treatment of cancer diseases.
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Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Lactoferrina/administração & dosagem , Lactoferrina/farmacologia , Melanoma/tratamento farmacológico , Melanoma/patologia , Animais , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Lipossomos , Camundongos , Relação Estrutura-AtividadeRESUMO
Salecan is a microbial polysaccharide suitable to obtain hydrogel for biomedical applications due to the excellent hydrophilicity and biocompatibility properties. In this work, Salecan of different concentrations was introduced into polymethacrylic acid (PMAA) in the presence of clay to form novel semi synthetic hydrogel nanocomposites systems and loaded afterwards with doxorubicin (DOX). The physical-chemical characteristics of the nanocomposites systems and their effect on the viability, and morphology of MDBK (Madin-Darby bovine kidney), HT-29 human colorectal adenocarcinoma and Colo 205 human colon adenocarcinoma cell lines were investigated. DOX release from the nanocomposite systems, cell up-take and subsequent effect on cell proliferation was also analyzed. It was found that Salecan concentration determined the swelling behavior, structural parameters and morphological features of the nanocomposite systems. The hydrogen bonds strongly influenced the formation of PMAA-Salecan-clay systems, each component bringing its own contribution, thus demonstrating the achievement of an advanced crosslinked network and a more compacted hydrogel nanocomposite morphology. All the synthesized nanocomposites had negligible toxicity to normal MDBK cells and chemoresistent HT-29 cell line, whereas in the case of Colo 205 cells a decrease by 40% of the cell viability was obtained for the sample containing the highest amount of Salecan. This effect was correlated with the lowest pore size distribution leading to highest available specific surface area and entrapped amount of DOX which was further released from the nanocomposite sample. Corroborating all the data it can be suggested that the synthesized nanocomposites with Salecan and clay could be good candidates as vehicles for chemotherapeutic agents.
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We report on the synthesis and evaluation of biopolymeric spheres of poly(lactide-co-glycolide) containing different amounts of magnetite nanoparticles and Ibuprofen (PLGA-Fe3O4-IBUP), but also chitosan (PLGA-CS-Fe3O4-IBUP), to be considered as drug delivery systems. Besides morphological, structural, and compositional characterizations, the PLGA-Fe3O4-IBUP composite microspheres were subjected to drug release studies, performed both under biomimetically-simulated dynamic conditions and under external radiofrequency magnetic fields. The experimental data resulted by performing the drug release studies evidenced that PLGA-Fe3O4-IBUP microspheres with the lowest contents of Fe3O4 nanoparticles are optimal candidates for triggered drug release under external stimulation related to hyperthermia effect. The as-selected microspheres and their chitosan-containing counterparts were biologically assessed on macrophage cultures, being evaluated as biocompatible and bioactive materials that are able to promote cellular adhesion and proliferation. The composite biopolymeric spheres resulted in inhibited microbial growth and biofilm formation, as assessed against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans microbial strains. Significantly improved antimicrobial effects were reported in the case of chitosan-containing biomaterials, regardless of the microorganisms' type. The nanostructured composite biopolymeric spheres evidenced proper characteristics as prolonged and controlled drug release platforms for multipurpose biomedical applications.
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Resumen: Introducción: uno de los principales efectos de la ventilación mecánica invasiva es la lesión de los músculos respiratorios, específicamente, sobre el diafragma en el que pueden ocurrir alteraciones estructurales y funcionales que modifican parcial o totalmente su función. Durante la ventilación mecánica se produce un proceso de atrofia por desuso de dicho músculo. Por ello la utilidad clínica de la medición de la fuerza muscular diafragmática es importante para conocer si el paciente tiene la capacidad de activar los mecanismos protectores de la vía aérea para lograr la extubación exitosa y el retiro del ventilador mecánico en el menor tiempo posible. Objetivos: describir la medición de la fuerza muscular como predictor de la extubación en las unidades de cuidados intensivos. Material y métodos: se realizó una revisión de la literatura, entre 2011 y 2022. Resultados: los pacientes que son sometidos a ventilación mecánica invasiva prolongada generalmente desarrollan una afección muscular diafragmática, lo que se convierte en una problemática para el proceso de extubación temprana, por lo cual es vital conocer los métodos de medición de fuerza muscular como predictor de extubación.
Abstract: Introduction: one of the main effects of invasive mechanical ventilation is injury to the respiratory muscles, specifically the diaphragm. In which structural and functional alterations can occur that partially or totally modify its function. During mechanical ventilation, a process of disuse atrophy of said muscle occurs. Therefore, the clinical utility of measuring diaphragmatic muscle strength is important to know if the patient has the ability to activate the protective mechanisms of the airway to achieve successful extubation and removal of the mechanical ventilator in the shortest time possible. Objective: describe the measurement of muscle strength as a predictor of extubation in intensive care units. Material and methods: a literature review was carried out, carried out between 2011 and 2022. Results: patients who are subjected to prolonged mechanical ventilation generally develop a diaphragmatic muscle disorder, becoming a problem for the weaning, for it is important know the methods of measuring muscle strength.
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Present study refers to the synthesis of new advanced materials based on poly(methacrylic acid) (PMAA) with previously reported own advanced modified clays by edge covalent bonding. This will create the premises to obtain nanocomposite hydrogels with combined hydrophilic-hydrophobic behavior absolutely necessary for co-delivery of polar/nonpolar substances. For the synthesis, N,N'-methylenebisacrylamide was used as cross-linker and ammonium persulphate as initiator. As a consequence of the inclusion of clay into the polymer matrix and the intercalation of PMAA between the layers as well as the presence of hydrophobic interactions occurred between partners, the final hydrogel nanocomposites possessed greater swelling degrees, slower de-swelling process and enhanced mechanical properties depending on the clay type in comparison with pure hydrogel. In vitro MTS ([3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt]) colorimetric assay showed that direct exposure with PMMA-clay-based constructs did not affect cell viability and proliferation in time (24 and 48 h) on either normal or adenocarcinoma cell lines.
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Polymeric nanoparticles (NPs) are known to facilitate intracellular uptake of drugs to improve their efficacy, with minimum bioreactivity. The goal of this study was to assess cellular uptake and trafficking of PLGA NPs and chitosan (Chi)-covered PLGA NPs in Madin-Darby bovine kidney (MDBK) and human colorectal adenocarcinoma (Colo 205) cells. Both PLGA and Chi-PLGA NPs were not cytotoxic to the studied cells at concentrations up to 2500 µg/mL. The positive charge conferred by the chitosan deposition on the PLGA NPs improved NPs uptake by MDBK cells. In this cell line, Chi-PLGA NPs colocalized partially with early endosomes compartment and showed a more consistent perinuclear localization than PLGA NPs. Kinetic uptake of PLGA NPs by Colo 205 was slower than that by MDBK cells, detected only at 24 h, exceeding that of Chi-PLGA NPs. This study offers new insights on NP interaction with target cells supporting the use of NPs as novel nutraceuticals/drug delivery systems in metabolic disorders or cancer therapy. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 3599-3611, 2015.
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Quitosana/farmacologia , Espaço Intracelular/metabolismo , Ácido Láctico/farmacologia , Nanopartículas/química , Ácido Poliglicólico/farmacologia , Animais , Bovinos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Endocitose/efeitos dos fármacos , Citometria de Fluxo , Humanos , Cinética , Microscopia de Fluorescência , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Eletricidade Estática , Tensoativos/químicaRESUMO
Existen muchos estudios sobre parálisis cerebral acerca de fisiopatología incluyendo síntomas, signos y características de este trastorno, desafortunadamente el número de publicaciones realizadas en rela-ción a la medición de deficiencias de orden cinético es escaso, profesionales como fisioterapeutas, que tienen como objeto de estudio el movimiento corporal humano, se ven limitados para cuantificar las mismas y por ende corroborar el resultado de las intervenciones. Por esta razón surge la necesidad de realizar una revisión sistemática, que arroje el panorama de test y medidas utilizadas para medir las deficiencias de orden funcional, en niños con parálisis cerebral (PC), para ello se buscan artículos en las bases de datos de Pubmed, Science Direct y Scielo, entre los años 2005 a 2012. El objetivo principal es reconocer cuales son los test y medidas usados en fisioterapia para la medición y evaluación de las deficiencias estructurales y funcionales que se presenten en niños con parálisis cerebral. De esta revi-sión se hallaron 1695 artículos de fisiopatología, etiología, características físicas, deficiencias motoras, sin embargo solo 19 abordan los diferentes test y medidas usados en fisioterapia para el manejo de niños con parálisis cerebral. En la literatura la antropometría y el desempeño muscular se miden de forma independiente, sin embargo, MACEDO y MILLER, contrastan sus teorías sobre características antropométricas y desempeño muscular de forma conjunta, frente a individuos con parálisis cerebral. Por último, la investigación concluye que la mayoría de evidencia encontrada analiza las deficiencias de integridad de nervios craneales y circulación.
Lots of studies talk about cerebral palsy andphysiopathology which includes symptoms, signs and characteristics; unfortunately, the number of publications in relation to the kinetic deficiency measurement is scarce. Professionals like physical therapists, whose their study aim is human corporal movement, are limited to quantify these publications and corroborate intervention results. For this reason, the necessity of making a systematic review that shows the panorama of tests and used measurements to evaluate and quantify functional deficiencies in children with cerebral palsy through articles search in data bases such as Pubmed, Science Direct and, Scielo between 2005 and 2012. The aim of this review is to recognize the tests and measurements that are used in Physical Therapy to assess and measure structural and functional deficiencies in children with cerebral palsy.In this part, 1695 articles were found about to physiopathology, etiology, physical characteristics and motor deficiencies; however, only 19 articles are related directly to our aim. Literature shows that anthropometry characteristics measurements and muscular performance are made independently, yet MACEDO and MILLER differ by measuring together these two characteristics in children with cerebral palsy. This investigation concludes that the majority of the evidence analyzes cranial nerves and circulation integrity deficiencies.