Fucoidan-Coated Silica Nanoparticles Promote the Differentiation of Human Mesenchymal Stem Cells into the Osteogenic Lineage.

Silica nanoparticles (SiNPs) are widely used in biomedical applications, such as cancer therapy/diagnosis or tissue engineering and regenerative medicine. Herein, we synthesized SiNPs and modified them with sulfonic acid groups (by organosilylation followed by oxidation) or a sulfated polysaccharide (i.e., fucoidan, a seaweed biopolymer, by using electrostatic surface immobilization) due to the known capacity of the sulfonic/sulfate moieties to stabilize proteins and promote stem cell differentiation toward the osteogenic lineage. The developed pristine and functionalized nanoparticles were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), showing the monodisperse size distribution (between 360 and 450 nm) and the success of the coating/functionalization with fucoidan or sulfonic groups. The developed SiNPs (at a concentration of 50 µg/mL) were assessed through their contact with SaOs2 cells evidencing their cytocompatibility. Furthermore, the osteogenic differentiation of bmMSCs was evaluated by the quantification of ALP activity, as well as the expression profile of osteogenic-related genes, such as Runx2, ALP, and OP. We found that the coating of the SiNPs with fucoidan induced the osteogenic differentiation of bmMSCs, being an effective mediator of bone regeneration.

In vitro antiviral effect of ethanolic extracts from Azadirachta indica and Melia azedarach against goat lentivirus in colostrum and milk.

This study aimed to evaluate, in vitro, the use of leaf extracts of Azadirachta indica (A. indica) and Melia azedarach (M. azedarach) as antivirals against caprine lentivirus (CLV) in colostrum and milk of goat nannies. These were collected from eight individuals and infected with the standard strain of CLV. Samples were then subdivided into aliquots and treated with 150 µg/mL of crude extract, and with ethyl acetate and methanol fractions for 30, 60, and 90 min. Next, somatic cells from colostrum and milk were co-cultured with cells from the ovine third eyelid. After this step, viral titers of the supernatants collected from treatments with greater efficacy in co-culture were assessed. The organic ethyl acetate fractions of both plants at 90 min possibly inhibited the viral activity of CLV by up to a thousandfold in colostrum. In milk, this inhibition was up to 800 times for the respective Meliaceae. In conclusion, the ethanolic fraction of ethyl acetate from both plants demonstrated efficacy against CLV in samples from colostrum and milk when subjected to treatment, which was more effective in colostrum.

Psychometric properties of the Portuguese version of the occupational fatigue exhaustion/recovery (OFER) scale among industrial shift workers.

Reliable and valid instruments are essential for understanding fatigue in occupational settings. This study analyzed the psychometric properties of the Portuguese version of the Occupational Fatigue Exhaustion/Recovery (OFER). A cross-sectional study was conducted with 260 workers (M = 46.52 ± 13.16 years) from a textile industry, exposed to shift work. Convergent and discriminant validity, internal consistency reliability and exploratory and confirmatory factor analysis were performed. Results showed an adequate fit to data (χ2 (84) = 209,102, CFI = 0.936, GFI = 0.902, RMSEA = 0.076 CI90% (0.063-0.089)), yielding a 13-item, three factor structure. Two items were removed due to low factor loading. The OFER presented an adequate internal consistency, with the subscales presenting good reliability values (Chronic Fatigue (α = 0.81), Acute Fatigue (α = 0.84) and Recovery between Shifts (α = 0.77)). Findings suggest that the Portuguese version of OFER can be a useful tool to assess occupational fatigue of shift workers and prevent work related injuries.

Hyaluronic acid hydrogels reinforced with laser spun bioactive glass micro- and nanofibres doped with lithium.

The repair of articular cartilage lesions in weight-bearing joints remains as a significant challenge due to the low regenerative capacity of this tissue. Hydrogels are candidates to repair lesions as they have similar properties to cartilage extracellular matrix but they are unable to meet the mechanical and biological requirements for a successful outcome. Here, we reinforce hyaluronic acid (HA) hydrogels with 13-93-lithium bioactive glass micro- and nanofibres produced by laser spinning. The glass fibres are a reinforcement filler and a platform for the delivery of therapeutic lithium-ions. The elastic modulus of the composites is more than three times higher than in HA hydrogels. Modelling of the reinforcement corroborates the experimental results. ATDC5 chondrogenic cells seeded on the composites are viable and more proliferation occurs on the hydrogels containing fibres than in HA hydrogels alone. Furthermore, the chondrogenic behavior on HA constructs with fibres containing lithium is more marked than in hydrogels with no-lithium fibres.

Adherence of community health workers to hepatitis B vaccination / Adesão de agentes comunitários de saúde à vacinação contra hepatite B

INTRODUCTION: Hepatitis B (HB) vaccination for health-care workers is essential for World Health Organization's goals achievement of viral hepatitis (VH) elimination. However, recent studies showed low vaccination adherence by these professionals and lack of knowledge about HB vaccination adherence of community health workers (CHW). OBJECTIVE: To identify the adherence of CHW to HB vaccination; to determine the causes of non-adherence; to investigate whether the prevalence of vaccination is different among surveyed towns, and to verify whether years practiced as CHW have any association with vaccination adherence. METHODS: This cross-sectional study included five towns (T) of a Brazilian state. Data were collected at VH educational meetings, in which CHW answered a questionnaire. The proportions Z-test and the likelihood ratio test were used for statistical analysis. Significance was set at p<0.05. RESULTS: The sample included 516 CHW. Most CHW (86.8%) reported to have taken the vaccine, but only 59.7% affirmed having taken all doses, and 28.1% correctly answered the number of doses. 24.4% of CHW pointed the unknowing about HB vaccine importance as the main reason for non-adherence. T4 and T5 showed higher vaccination prevalence than T2 and T1. Vaccination adherence was higher among individuals with more years working as CHW. CONCLUSION: CHW demonstrated low adherence to HB vaccination and pointed the lack of knowledge about HB vaccine importance as the main reason for that. There were differences in vaccination prevalence among the towns and adherence was positively associated with professional experience.

INTRODUÇÃO: A vacinação dos profissionais de saúde contra hepatite B (HB) é fundamental para que sejam atingidas as metas da Organização Mundial de Saúde de eliminação das hepatites virais (HV). Entretanto, estudos recentes mostram baixa aderência desses profissionais à vacinação e falta conhecimento sobre a adesão dos agentes comunitários de saúde (ACS) à vacinação. OBJETIVO: Identificar a adesão dos ACS à vacinação contra HB; determinar as causas da não adesão; investigar se a prevalência de vacinação é diferente entre os municípios (M) pesquisados; e verificar se o tempo de experiência como ACS está associado à adesão. MÉTODOS: Estudo transversal incluindo cinco municípios de um estado brasileiro. Os dados foram coletados em palestras sobre HB, nas quais os ACS responderam um questionário. Foram aplicados o teste de proporções (Z) e a razão de verossimilhança, considerando-se significante p<0,05. RESULTADOS: A amostra incluiu 516 ACS, dos quais 86,8% relataram ter tomado a vacina, 59,7% afirmaram ter tomado todas as doses, 28,1% responderam corretamente o número de doses e 24,4% apontaram o desconhecimento sobre a importância da vacina como o principal motivo de não adesão. M4 e M5 mostraram maior prevalência de vacinação que M2 e M1. Os ACS com maior tempo de experiência profissional apresentaram maior adesão. CONCLUSÃO: Os ACS demonstraram baixa adesão à vacinação contra HB e indicaram a falta de conhecimento sobre a importância da vacina como a principal causa. Houve diferenças na prevalência de vacinação entre os municípios e a aderência foi positivamente associada ao tempo de experiência profissional.

Extracellular Matrix Mimics Using Hyaluronan-Based Biomaterials.

Hyaluronan (HA) is a critical element of the extracellular matrix (ECM). The regulated synthesis and degradation of HA modulates the ECM chemical and physical properties that, in turn, influence cellular behavior. HA triggers signaling pathways associated with the adhesion, proliferation, migration, and differentiation of cells, mediated by its interaction with specific cellular receptors or by tuning the mechanical properties of the ECM. This review summarizes the recent advances on strategies used to mimic the HA present in the ECM to study healthy or pathological cellular behavior. This includes the development of HA-based 2D and 3D in vitro tissue models for the seeding and encapsulation of cells, respectively, and HA particles as carriers for the targeted delivery of therapeutic agents.

Multilayer platform to model the bioactivity of hyaluronic acid in gastric cancer.

Hyaluronic acid (HA) has a key role in cancer progression. The HA's molecular weight (Mw) is altered in this pathological state: increased concentration of shorter fragments due to the overexpressed hyaluronidases and ROS. Aiming to mimic this microenvironment, we developed a Layer-by-Layer (LbL) platform presenting HA of different Mws, namely 6.4, 752 and 1500 kDa, to study the influence of HA Mw on the formation of focal adhesion sites (FAs), and the involvement of paxillin and CD44 in this process. High paxillin expression and formation of FAs, via CD44, is observed for MKN45 cells seeded on LbLs presenting HA 6.4 kDa, with the activation of the ERK1/2 pathway, responsible for cell motility and tumour progression. In contrast, activation of p38 pathway, usually related with cancer latency, is observed for cells seeded on LbLs with high Mw HA, i.e. 1500 kDa. Overall, we demonstrate the suitability of the developed platform to study cancer invasiveness.

3D hydrogel mimics of the tumor microenvironment: the interplay among hyaluronic acid, stem cells and cancer cells.

The present work reports on a 3D model of the tumor microenvironment that contains hyaluronic acid (HA) and alginate, and demonstrates the utility of this model to study the effect of HA size on the crosstalk between cancer cells and mesenchymal stem cells (MSCs). The system incorporates a core that contains HA of specific size (i.e. 6.4, 741 or 1500 kDa) with encapsulated epithelial MKN45 cancer cells and a shell with MSCs that mimic the presence of stem cells next to the tumor site. It was found that short HA (i.e. 6.4 kDa) promotes the invasion of cancer cells from the core to the shell, whereas longer HA (i.e. 741 and 1500 kDa) recruits the MSCs into the core, i.e. the tumor site, where a reduction of the formation of cancer cell aggregates was observed. In summary, the developed 3D model recapitulates some key tumor features related to the effect of HA size on both cancer cell invasiveness and MSC behavior at the tumor site.

Fibronectin-Functionalized Fibrous Meshes as a Substrate to Support Cultures of Thymic Epithelial Cells.

Thymic epithelial cells (TECs) are the main regulators of T lymphocyte development and selection, requiring a three-dimensional (3D) environment to properly perform these biological functions. The aim of this work was to develop a 3D culture substrate that allows the survival and proliferation of TECs. Thus, electrospun fibrous meshes (eFMs) were functionalized with fibronectin, one of the major extracellular matrix (ECM) proteins of the thymus. For that, highly porous eFMs were activated using oxygen plasma treatment followed by amine insertion, which allows the immobilization of fibronectin through EDC/NHS chemistry. The medullary TECs presented increased proliferation, viability, and protein synthesis when cultured on fibronectin-functionalized eFMs (FN-eFMs). These cells showed a spread morphology, with increased migration toward the inner layers of FN-eFMs and the production of thymic ECM proteins, such as collagen type IV and laminin. These results suggest that FN-eFMs are an effective substrate for supporting thymic cell cultures.

Hyaluronic Acid of Low Molecular Weight Triggers the Invasive "Hummingbird" Phenotype on Gastric Cancer Cells.

The overproduction and deposition of hyaluronic acid (HA) of different sizes in the tumor microenvironment is associated with cancer metastasis. Here, the development of layer-by-layer (LbL) constructs containing HA of different molecular weights (i.e., 5.6, 618, and 1450 kDa) that mimic the HA-rich cancer extracellular matrix is described to study the effect of the HA's size on the behavior of gastric cancer cells (AGS). The results demonstrate that LbL constructs with short HA, i.e., 5.6 kDa, activate the cytoskeleton rearrangement leading to the "hummingbird" morphology, promote high cellular motility, and activate signaling pathways with increased expression of p-ERK1/2 and p-AKT. In addition, it is demonstrated that this malignant transformation involves an active participation of the HA coreceptor RHAMM in AGS cells.

Tubular Fibrous Scaffolds Functionalized with Tropoelastin as a Small-Diameter Vascular Graft.

Cardiovascular disorders are a healthcare problem in today's society. The clinically available synthetic vascular grafts are thrombogenic and could induce intimal hyperplasia. Rapid endothelialization and matched mechanical properties are two major requirements to be considered when designing functional vascular grafts. Herein, an electrospun tubular fibrous (eTF) scaffold was biofunctionalized with tropoelastin at the luminal surface. The luminal surface functionalization was confirmed by an increase of the zeta potential and by the insertion of NH2 groups. Tropoelastin was immobilized via its -NH2 or -COOH groups at the activated or aminolysed eTF scaffolds, respectively, to study the effect of exposed functional groups on human endothelial cells (ECs) behavior. Tensile properties demonstrated that functionalized eTF scaffolds presented strength and stiffness within the range of those of native blood vessels. Tropoelastin immobilized on activated eTF scaffolds promoted higher metabolic activity and proliferation of ECs, whereas when immobilized on aminolysed eTF scaffolds, significantly higher protein synthesis was observed. These biofunctional eTF scaffolds are a promising small-diameter vascular graft that promote rapid endothelialization and have compatible mechanical properties.

Tunable layer-by-layer films containing hyaluronic acid and their interactions with CD44.

We report on the development of layer-by-layer (LbL) constructs whose viscoelastic properties and bioactivity can be finely tuned by using polyanions of different size and/or crosslinking. As a polyanion we used hyaluronic acid (HA) - a multi-signaling biomolecule whose bioactivity depends on its molecular weight. We investigated the interplay between the mechanical properties of the LbL systems built using HA of different sizes and the specific HA-mediated biochemical interactions. We characterized the assembled materials and their interactions with CD44, the main HA receptor, by Quartz Crystal Microbalance with Dissipation (QCM-D), Surface Plasmon Resonance (SPR) and Atomic Force Microscopy (AFM). We observed that the presence of CD44 resulted in the disruption of the non-crosslinked multilayers, while crosslinked films remain stable and bind CD44 in a HA molecular weight and charge specific fashion.

Molecular weight of surface immobilized hyaluronic acid influences CD44-mediated binding of gastric cancer cells.

The physiological importance of the interactions between hyaluronic acid (HA) and its main membrane receptor, CD44, in pathological processes, e.g. cancer, is well recognized. However, these interactions are mainly studied in solution, whereas HA in the extracellular matrix (ECM) is partially immobilized via its interactions with other ECM components. We therefore, developed substrates in which HA is presented in an ECM-relevant manner. We immobilized HA with different molecular weights (Mw) in a Layer-by-Layer (LbL) fashion and studied the interactions of the substrates with CD44 and two human gastric cancer cell lines that overexpress this receptor, namely AGS and MKN45. We demonstrate that MKN45 cells are more sensitive to the LbL substrates as compared with AGS. This difference is due to different CD44 expression: while CD44 is detected mainly in the cytoplasm of AGS, MKN45 express CD44 predominantly at the cell membrane where it is involved in the recognition and binding of HA. The invasiveness of the studied cell lines was also evaluated as a function of HA Mw. Invasive profile characterized by low cell adhesion, high cell motility, high expression of cortactin, formation of invadopodia and cell clusters was observed for MKN45 cells when they are in contact with substrates presenting HA of high Mw.

Fish sarcoplasmic proteins as a high value marine material for wound dressing applications.

Fish sarcoplasmic proteins (FSP) constitute around 25-30% of the total fish muscle protein. As the FSP are water soluble, FSP were isolated from fresh cod (Gadus morhua) by centrifugation. By SDS-PAGE, it was possible to determine the composition of FSP extracts (FSP-E). The FSP-E undergo denaturation at 44.12 ±â€¯2.34°â€¯C, as characterized by differential scanning calorimetry thermograms (DSC). The secondary structure of FSP-E is mainly composed by α-helix structure, as determined by circular dichroism. The cytocompatibility of FSP-E, at concentrations ranging from 5 to 20 mg/mL, was investigated. Concentrations lower than 10 mg/mL have no cytotoxicity cultures of fibroblasts over 72 h. Further on, FSP membranes (FSP-M) were produced by spin coating to evaluate its properties. FSP-M shown having uniform surface as analyzed by Scanning Electron Microscopy (SEM). The relative amount of α-helix structures is higher when compared with the FSP-E. The FSP-M have higher temperature stability than the FSP-E, since they presented a denaturation temperature of 58.88 ±â€¯3.36°â€¯C, according to the DSC analysis. FSP-M shown distinctive mechanical properties, with a stiffness of 16.57 ±â€¯3.95 MPa and a yield strength of 23.85 ±â€¯5.97 MPa. Human lung fibroblasts cell lines (MRC-5) were cultured in direct contact with FSP-M, demonstrating its cytocompatibility for 48 h. Based on these results, FSP can be considered a potential biomaterial recovered from nature, for wound dressing applications.

The functionalization of natural polymer-coated gold nanoparticles to carry bFGF to promote tissue regeneration.

Gold nanoparticles (AuNPs) enable the treatment and real-time monitoring of several diseases, providing an exciting and advantageous nanomedicine strategy. These NPs have therefore been adequately functionalized to enable them to carry growth factors (GF), namely basic fibroblastic (bF) GF, which play an essential role in different and important cellular processes including cellular proliferation, survival, migration and differentiation. The AuNPs were coated with natural polymers, chitosan and heparin, to enhance their physicochemical properties such as suspension stability. The polyelectrolyte coating was monitored using a quartz crystal microbalance with dissipation, size and zeta-potential analysis. The natural polymer-coated AuNPs have a spherical shape and a positive surface charge due to chitosan amino groups, enabling their biofunctionalization with monoclonal antibodies to target specific biomolecules. Additionally, cellular assays with the chondrocyte cell line ATDC5 show that the NPs are cytocompatible at relevant concentrations. As a proof of concept of their potential application in tissue regeneration, the natural polymer-coated AuNPs were further functionalized with an antibody to selectively bind the desired GF. The bFGF concentration reached in the NPs without compromising the cytocompatibility demonstrates the potential of this carrier for tissue regeneration.

Eventos adversos judicializados no Distrito Federal: um retrato de 2016

A atividade do profissional da área médica pode suscitar em morte do paciente ou o comprometimento de sua integridade física ou de sua saúde, por conduta culposa (negligência, imperícia ou imprudência). Esses atos geram ações de responsabilidade civil levando-o a ressarcir os danos produzidos ao paciente ou ações de responsabilidade penal trazendo consequências criminais agente. Este artigo realizou uma pesquisa jurisprudencial a partir do levantamento de dados dos acórdãos em segunda instância disponível no site do TJDFT no período de janeiro a dezembro de 2016, utilizando os termos "erro médico" no campo disponibilizado para pesquisa resultando um total de 285 processos. Desta analise 5% tratavam de dano material, 52% sobre danos morais e 43% relacionados a danos morais e materiais; as especialidades de maior número de processos foram gineco-obstetrícia, cirurgia geral e plástica; ações cujo o réu foi o setor privado em 44%, o setor público 56% dos pleitos; as sentenças foram improcedentes em 52%, procedentes em 19% parcialmente procedentes em 29% dos processos analisados.

Surfaces Mimicking Glycosaminoglycans Trigger Different Response of Stem Cells via Distinct Fibronectin Adsorption and Reorganization.

We report on the utility of a platform created by self-assembled monolayers to investigate the influence of the degree of sulfation of glycosaminoglycans (GAGs) on their interactions with fibronectin (Fn) and the impact of these interactions on the adhesion and morphology of human adipose derived stem cells (ASCs). We used the label-free QCM-D, AFM and SPR to follow the changes in the protein adlayer in close proximity to the substrates surface and QCM-D in combination with live imaging to characterize the adherent cells. Our results suggest that Fn interactions with GAGs are governed by both H-bonding and electrostatic forces. Strong electrostatic interactions cause irreversible change in the protein conformation, while the weaker H-bonding only partially restricts the protein flexibility, allowing Fn reorganization and exposure of its binding sites for ASC adhesion. These findings imply that a delicate balance between these two types of forces must be considered in the design of biomaterials that mimic GAGs.

Bacteria-responsive multilayer coatings comprising polycationic nanospheres for bacteria biofilm prevention on urinary catheters.

This work reports on the development of infection-preventive coatings on silicone urinary catheters that contain in their structure and release on demand antibacterial polycationic nanospheres. Polycationic aminocellulose conjugate was first sonochemically processed into nanospheres to improve its antibacterial potential compared to the bulk conjugate in solution (ACSol). Afterward the processed aminocellulose nanospheres (ACNSs) were combined with the hyaluronic acid (HA) polyanion to build a layer-by-layer construct on silicone surfaces. Although the coating deposition was more effective when HA was coupled with ACSol than with ACNSs, the ACNSs-based coatings were thicker and displayed smoother surfaces due to the embedment of intact nanospheres. The antibacterial effect of ACNSs multilayers was 40% higher compared to ACSol coatings. This fact was further translated into more effective prevention of Pseudomonas aeruginosa biofilm formation. The coatings were stable in the absence of bacteria, whereas their disassembling occurred gradually during incubation with P. aeruginosa, and thus eradicate the biofilm upon release of antibacterial agents. Only 5 bilayers of HA/ACNSs were sufficient to prevent the biofilm formation, in contrast to the 10 bilayers of ACSol required to achieve the same effect. The antibiofilm efficiency of (HA/ACNSs)10 multilayer construct built on a Foley catheter was additionally validated under dynamic conditions using a model of the catheterized bladder in which the biofilm was grown during seven days. STATEMENT OF SIGNIFICANCE: Antibacterial layer-by-layer coatings were fabricated on silicone that efficiently prevents Pseudomonas aeruginosa biofilm formation during time beyond the useful lifetime of the currently employed urinary catheters in medical practice. The coatings are composed of intact, highly antibacterial polycationic nanospheres processed from aminated cellulose and bacteria-degrading glycosaminoglycan hyaluronic acid. The importance of incorporating nanoscale structures within bacteria-responsive surface coatings to impart durable antibacterial and self-defensive properties to the medical indwelling devices is highlighted.

Hyaluronic acid/poly-l-lysine bilayered silica nanoparticles enhance the osteogenic differentiation of human mesenchymal stem cells.

Herein, we evaluate the influence of a PLL-HA bilayer on the surface of silica nanoparticles on their capacity to induce the osteogenic differentiation of human bone marrow stem cells (hBMSCs), as a function of their concentration (50 µg mL-1, 25 µg mL-1 and 12.5 µg mL-1). To this purpose, we synthesized silica nanoparticles (diameter of ∼250 nm; ζ-potential of -25 mV) that were coated with PLL-HA (diameter of ∼560 nm; ζ-potential of -35 mV). The cell viability, cell proliferation, protein quantification (i.e. MTS, DNA and ALP, respectively) and gene expression (of osteogenesis-related genes: ALP, osteocalcin, collagen type I, bone sialoprotein, Runx-2, osteopontin and osterix) were monitored, for 21 days. We observed the overexpression of most of the tested osteogenic transcripts in the hBMSCs cultured with SiO2-PLL-HA, at concentrations of 25 µg mL-1 and 12.5 µg mL-1. These results indicate that the proposed nanoparticles temporarily improve the osteogenic differentiation of hBMSCs at low nanoparticle concentrations.

Interactions between exogenous FGF-2 and sulfonic groups: in situ characterization and impact on the morphology of human adipose-derived stem cells.

FGF-2 is often used as a supplement to stem cells culture medium aiming at preserving their self-renewal capacity and plasticity through the passages. However, little is known on the influence of the underlying substrate in these interactions. In this study, we have used mixed self-assembled monolayers with different ratios of -SO3H and -OH tail groups to investigate the influence of substrate properties (e.g., charge) on the FGF-2 adsorption and activity. QCM-D data demonstrated that, in the presence of -OH groups, the quantity of the adsorbed FGF-2 is proportional to the percentage of surface -SO3H groups. The bioactivity of the adsorbed FGF-2 follows the same tendency as demonstrated by its interactions with anti-FGF-2. Surprisingly, the adlayer of FGF-2 formed on the surface containing only SO3H-tailed SAMs was similar to the surface with 25% of -SO3H groups, demonstrating that FGF-2 adsorption is not solely driven by electrostatic interactions. We related these results with changes in the morphology of adipose-derived stem cells (ASCs) cultured on the same surfaces.