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1.
J Phys Chem Lett ; 15(13): 3576-3580, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38527009

RESUMEN

This study demonstrates the existence of temperature-induced molecular bonding hysteresis at nanoparticle-polymer interfaces in a highly cross-linked epoxy-based polymer, modified with core-shell rubber nanoparticles. This thermally induced bond hysteresis manifests itself in a hysteresis-like change of the strength of the electrical bond polarization between epoxy molecules and surface molecules of the core-shell nanoparticles. This kind of dynamic bond behavior can be controllably switched from one bond state to the other by a sufficient temperature change. The related optical remanence is evidenced by a refractive index hysteresis independent of the temperature change using the new experimental technique of temperature-modulated optical refractometry (TMOR). From the investigation of quasi-static and dynamic thermal expansion separately, TMOR allows for the conclusion that the observed hysteresis is caused by the specific refractivity and not the dipole number density.

2.
Trends Cogn Sci ; 28(1): 43-55, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37696692

RESUMEN

People increasingly read text displayed on digital devices, including computers, handheld e-readers, and smartphones. Given this, there is rapidly growing interest in understanding how the cognitive processes that support the reading of static text (e.g., books, magazines, or newspapers) might be adapted to reading digital texts. Evidence from recent experiments suggests a complex interplay of visual and cognitive influences on how people engage with digital reading. Although readers can strategically adjust their reading behaviors in response to their immediate reading context, the efficacy of these strategies depends on cognitive, metacognitive, and motivational factors. A better understanding of the factors that influence reading offers the promise of leveraging digital technologies to enhance the reading experience.


Asunto(s)
Metacognición , Lectura , Humanos , Cognición , Libros , Motivación
3.
Sci Rep ; 13(1): 21846, 2023 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-38071261

RESUMEN

Serological assays measuring antibodies against SARS-CoV-2 are key to describe the epidemiology, pathobiology or induction of immunity after infection or vaccination. Of those, multiplex assays targeting multiple antigens are especially helpful as closely related coronaviruses or other antigens can be analysed simultaneously from small sample volumes, hereby shedding light on patterns in the immune response that would otherwise remain undetected. We established a bead-based 17-plex assay detecting antibodies targeting antigens from all coronaviruses pathogenic for humans: SARS-CoV-2, SARS-CoV, MERS-CoV, HCoV strains 229E, OC43, HKU1, and NL63. The assay was validated against five commercial serological immunoassays, a commercial surrogate virus neutralisation test, and a virus neutralisation assay, all targeting SARS-CoV-2. It was found to be highly versatile as shown by antibody detection from both serum and dried blot spots and as shown in three case studies. First, we followed seroconversion for all four endemic HCoV strains and SARS-CoV-2 in an outbreak study in day-care centres for children. Second, we were able to link a more severe clinical course to a stronger IgG response with this 17-plex-assay, which was IgG1 and IgG3 dominated. Finally, our assay was able to discriminate recent from previous SARS-CoV-2 infections by calculating the IgG/IgM ratio on the N antigen targeting antibodies. In conclusion, due to the comprehensive method comparison, thorough validation, and the proven versatility, our multiplex assay is a valuable tool for studies on coronavirus serology.


Asunto(s)
COVID-19 , Coronavirus Humano OC43 , Coronavirus del Síndrome Respiratorio de Oriente Medio , Niño , Humanos , SARS-CoV-2 , Inmunidad Humoral , COVID-19/diagnóstico , COVID-19/epidemiología , Inmunoglobulina G , Anticuerpos Antivirales
4.
Front Microbiol ; 14: 1256210, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37937220

RESUMEN

Background: COVID-19 can show a variable course, from asymptomatic infections to acute respiratory failure and death. For efficient allocation of resources, patients should be stratified according to their risk for a severe course as early as possible. Methods: 135 hospitalized patients with COVID-19 pneumonia at four German hospitals were prospectively included in this observational study. A standardized clinical laboratory profile was taken at hospital admission and a panel of serum markers with possible roles in the COVID-associated cytokine storm were also determined. 112 patients could be evaluated. The primary endpoint of ventilator requirement or death within 30 days of symptom onset was met by 13 patients. Results: Serum elevations of interleukin-6 (IL-6), procalcitonin (PCT), and C-reactive protein (CRP) at hospital admission were each highly significantly (p < 0.001) associated with ventilator requirement/death within 30 days of symptom onset. With a sensitivity of 92% and a specificity of 65-67%, IL-6 ≥ 52.8 pg/ml, PCT ≥ 0.11 ng/ml, and CRP ≥ 71.1 mg/L were predictive of a severe course of COVID-19. Positive likelihood ratios were between 2.6-2.8 and negative likelihood ratios were between 0.11-0.13 for these three markers. Conclusion: Negative likelihood ratios indicate that IL-6, PCT, and CRP at hospital admission can be used for identifying patients at low risk for severe COVID-19 progression.

5.
Front Psychiatry ; 14: 1228192, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37829760

RESUMEN

Introduction: The common connecting factor between PTSD and cardiovascular diseases lies in the disruption of the stress processing system. The COVID-19 pandemic has led to an increase in stress levels worldwide. Due to the life-threatening situation of affected risk patients, this also led to the accumulation of post-traumatic stress symptoms (PTSS). The influence of anger on cardiovascular diseases has hardly been investigated so far. The focus of this study is on anger regulation in cardiovascular risk patients. The COVID-19 pandemic is considered as an additional stressor in this study, but not as a separate entity. The hypothesis is that individuals with inward anger are more prone to post-traumatic stress disorder (PTSD). Methods: As part of the routine examination, all patients who were hospitalized between January 1st, 2021 and May 31st, 2022 with high-risk cardiovascular diseases were included. A total of N = 153 (84.1%) subjects participated in the study. On admission, anger (STAXI-2) and PTSD (PCL-5) were assessed using questionnaires. The relationship between different domains of anger and PTSS was examined. Results: Inwardly directed anger was more pronounced in this population than in a standard sample (+1 SD) and had a significant impact on the presence of PTSD (B = -0.72, p < 0.001). Additionally, correlations were found between inward-directed anger and PTSD, as well as all other anger expressions studied and the PTSD total score. Discussion: It can be assumed that anger and its regulation are relevant factors for both cardiac diseases and PTSD. The study results can be used for prevention, rehabilitation and therapeutic measures. However, the impact of inner anger on PTSD is theoretical and based on statistical testing. A confirmatory longitudinal study is needed to substantiate these results.

6.
Appl Opt ; 62(3): 756-763, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36821281

RESUMEN

In this contribution, we present a technique for in situ determination of the numerical apertures (NAs) of optical microscopes using calibrated diffraction gratings. Many commonly practiced procedures use an external setup to determine the objective and condenser NAs. However, these values may become modified in the used microscope systems, e.g., by system intrinsic apertures. Therefore, in our improved technique, determination of the imaging NA is conducted in situ within the corresponding microscope at hand. Furthermore, the method has been extended to yield the microscope's illumination NA as well. In total, we tested this procedure for determination of the imaging NA for four different microscope objectives with nominal values of 0.55 and 0.9, together with the illumination NAs for four different circular aperture diaphragms with diameters between 10 µm and 500 µm using several gratings of different pitches. All determined NA values agree essentially with their nominal values within their experimental uncertainties, but the uncertainties have been reduced by typically an order of magnitude as compared with the manufacturer's specifications.

7.
Environ Sci Technol ; 56(23): 17410-17419, 2022 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-36399683

RESUMEN

Peatlands store carbon in the form of dead organic residues. Climate change and human impact impose risks on the sustainability of the peatlands carbon balance due to increased peat decomposition. Here, we investigated molecular changes in the upper peat layers (0-40 cm), inferred from high-resolution vertical depth profiles, from a boreal peatland using two-dimensional 1H-13C nuclear magnetic resonance (NMR) spectroscopy, and comparison to δ13C, δ15N, and carbon and nitrogen content. Effects of hydrological conditions were investigated at respective sites: natural moist, drainage ditch, and natural dry. The molecular characterization revealed preferential degradation of specific side-chain linkages of xylan-type hemicelluloses within 0-14 cm at all sites, indicating organic matter losses up to 25%. In contrast, the xylan backbone, galactomannan-type hemicelluloses, and cellulose were more resistant to degradation and accumulated at the natural moist and drainage site. δ13C, δ15N, and carbon and nitrogen content did not correlate with specific hemicellulose structures but reflected changes in total carbohydrates. Our analysis provides novel insights into peat carbohydrate decomposition and indicates substantial organic matter losses in the acrotelm due to the degradation of specific hemicellulose structures. This suggests that variations in hemicellulose content and structure influence peat stability, which may have important implications with respect to climate change.


Asunto(s)
Suelo , Xilanos , Humanos , Suelo/química , Carbono/química , Nitrógeno/análisis
8.
J Funct Biomater ; 13(4)2022 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-36278654

RESUMEN

The development of bioresorbable materials for temporary implantation enables progress in medical technology. Iron (Fe)-based degradable materials are biocompatible and exhibit good mechanical properties, but their degradation rate is low. Aside from alloying with Manganese (Mn), the creation of phases with high electrochemical potential such as silver (Ag) phases to cause the anodic dissolution of FeMn is promising. However, to enable residue-free dissolution, the Ag needs to be modified. This concern is addressed, as FeMn modified with a degradable Ag-Calcium-Lanthanum (AgCaLa) alloy is investigated. The electrochemical properties and the degradation behavior are determined via a static immersion test. The local differences in electrochemical potential increase the degradation rate (low pH values), and the formation of gaps around the Ag phases (neutral pH values) demonstrates the benefit of the strategy. Nevertheless, the formation of corrosion-inhibiting layers avoids an increased degradation rate under a neutral pH value. The complete bioresorption of the material is possible since the phases of the degradable AgCaLa alloy dissolve after the FeMn matrix. Cell viability tests reveal biocompatibility, and the antibacterial activity of the degradation supernatant is observed. Thus, FeMn modified with degradable AgCaLa phases is promising as a bioresorbable material if corrosion-inhibiting layers can be diminished.

9.
J Biomed Mater Res B Appl Biomater ; 110(10): 2310-2322, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35532378

RESUMEN

Stereolithographic bioprinting holds great promise in the quest for creating artificial, biomimetic cartilage-like tissue. To introduce a more biomimetic approach, we examined blending and stratifying methacrylated hyaluronic acid (HAMA) and methacrylated gelatin (GelMA) bioinks to mimic the zonal structure of articular cartilage. Bioinks were suspended with porcine chondrocytes before being printed in a digital light processing approach. Homogenous constructs made from hybrid bioinks of varying polymer ratios as well as stratified constructs combining different bioink blends were cultivated over 14 days and analyzed by histochemical staining for proteoglycans/collagen type II, cartilage marker expression analysis, and for cellular viability. The stiffness of blended bioinks increased gradually with HAMA content, from 2.41 ± 0.58 kPa (5% GelMA, 0% HAMA) to 8.84 ± 0.11 kPa (0% GelMA, 2% HAMA). Cell-laden constructs maintained vital chondrocytes and supported the formation of proteoglycans and collagen type II. Higher concentrations of GelMA resulted in increased formation of cartilaginous matrix proteins and a more premature phenotype. However, decreased matrix production in central areas of constructs was observed in higher GelMA content constructs. Biomimetically stratified constructs retained their gradient-like structure even after ECM formation, and exclusively exhibited a significant increase in COL2A1 gene expression (+178%). Concluding, we showed the feasibility of blending and stratifying photopolymerizable, natural biopolymers by SLA bioprinting to modulate chondrocyte attributes and to create zonally segmented ECM structures, contributing to improved modeling of cartilaginous tissue for regenerative therapies or in vitro models.


Asunto(s)
Bioimpresión , Cartílago Articular , Animales , Bioimpresión/métodos , Colágeno Tipo II/química , Gelatina/química , Ácido Hialurónico/química , Hidrogeles/química , Impresión Tridimensional , Proteoglicanos , Porcinos , Ingeniería de Tejidos/métodos , Andamios del Tejido/química
10.
J Clin Virol ; 145: 105018, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34775143

RESUMEN

OBJECTIVES: The global spread of SARS-CoV-2 is a serious public health issue. Large-scale surveillance screenings are crucial but can exceed test capacities. We (A) optimized test conditions and (B) implemented pool testing of respiratory swabs into SARS-CoV-2 diagnostics. STUDY DESIGN: (A) We determined the optimal pooling strategy and pool size. In addition, we measured the impact of vortexing prior to sample processing, compared a pipette-pooling method (by combining transport medium of several specimens) and a swab-pooling method (by combining several swabs into a test tube filled with PBS) as well as determined the sensitivities of three PCR assays. (B) Finally, we applied high-throughput pool testing for diagnostics. RESULTS: (A) In a low prevalence setting, we defined a preferable pool size of ten in a two-stage hierarchical pool testing strategy. Vortexing of swabs (n = 33) increased cellular yield by a factor of 2.34. By comparing Ct-values of 16 pools generated with two different pooling strategies, pipette-pooling was more efficient compared to swab-pooling. Measuring dilution series of 20 SARS-CoV-2 positive samples in three PCR assays simultaneously revealed detection rates of 85% (assay I), 50% (assay II), and 95% (assay III) at a 1:100 dilution. (B) We systematically pooled 55,690 samples in a period of 44 weeks resulting in a reduction of 47,369 PCR reactions. CONCLUSIONS: For implementing pooling strategies into high-throughput diagnostics, we recommend utilizing a pipette-pooling method, performing sensitivity validation of the PCR assays used, and vortexing swabs prior to analyses. Pool testing for SARS-CoV-2 detection is feasible and effective in a low prevalence setting.


Asunto(s)
COVID-19 , SARS-CoV-2 , Prueba de COVID-19 , Humanos , ARN Viral , Sensibilidad y Especificidad , Manejo de Especímenes
11.
BMC Bioinformatics ; 21(1): 490, 2020 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-33129266

RESUMEN

BACKGROUND: Post-translational modifications (PTM) of amino acid (AA) side chains in peptides control protein structure and functionality. PTMs depend on the specific AA characteristics. The reactivity of cysteine thiol-based PTMs are unique among all proteinaceous AA. This pipeline aims to ease the identification of conserved AA of polypeptides or protein families based on the phylogenetic occurrence in the plant kingdom. The tool is customizable to include any species. The degree of AA conservation is taken as indicator for structural and functional significance, especially for PTM-based regulation. Further, this pipeline tool gives insight into the evolution of these potentially regulatory important peptides. RESULTS: The web-based or stand-alone pipeline tool Conserved Cysteine Finder (ConCysFind) was developed to identify conserved AA such as cysteine, tryptophan, serine, threonine, tyrosin and methionine. ConCysFind evaluates multiple alignments considering the proteome of 21 plant species. This exemplar study focused on Cys as evolutionarily conserved target for multiple redox PTM. Phylogenetic trees and tables with the compressed results of the scoring algorithm are generated for each Cys in the query polypeptide. Analysis of 33 translation elongation and release factors alongside of known redox proteins from Arabidopsis thaliana for conserved Cys residues confirmed the suitability of the tool for identifying conserved and functional PTM sites. Exemplarily, the redox sensitivity of cysteines in the eukaryotic release factor 1-1 (eRF1-1) was experimentally validated. CONCLUSION: ConCysFind is a valuable tool for prediction of new potential protein PTM targets in a broad spectrum of species, based on conserved AA throughout the plant kingdom. The identified targets were successfully verified through protein biochemical assays. The pipeline is universally applicable to other phylogenetic branches by customization of the database.


Asunto(s)
Algoritmos , Aminoácidos/química , Secuencia Conservada , Proteínas de Plantas/química , Plantas/metabolismo , Secuencia de Aminoácidos , Arabidopsis/genética , Oxidación-Reducción , Filogenia , Procesamiento Proteico-Postraduccional
12.
Int J Mol Sci ; 21(6)2020 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-32245213

RESUMEN

Intervertebral disc (IVD) herniation and degeneration is a major source of back pain. In order to regenerate a herniated and degenerated disc, closure of the anulus fibrosus (AF) is of crucial importance. For molecular characterization of AF, genome-wide Affymetrix HG-U133plus2.0 microarrays of native AF and cultured cells were investigated. To evaluate if cells derived from degenerated AF are able to initiate gene expression of a regenerative pattern of extracellular matrix (ECM) molecules, cultivated cells were stimulated with bone morphogenetic protein 2 (BMP2), transforming growth factor ß1 (TGFß1) or tumor necrosis factor-α (TNFα) for 24 h. Comparative microarray analysis of native AF tissues showed 788 genes with a significantly different gene expression with 213 genes more highly expressed in mild and 575 genes in severe degenerated AF tissue. Mild degenerated native AF tissues showed a higher gene expression of common cartilage ECM genes, whereas severe degenerated AF tissues expressed genes known from degenerative processes, including matrix metalloproteinases (MMP) and bone associated genes. During monolayer cultivation, only 164 differentially expressed genes were found. The cells dedifferentiated and altered their gene expression profile. RTD-PCR analyses of BMP2- and TGFß1-stimulated cells from mild and severe degenerated AF tissue after 24 h showed an increased expression of cartilage associated genes. TNFα stimulation increased MMP1, 3, and 13 expression. Cells derived from mild and severe degenerated tissues could be stimulated to a comparable extent. These results give hope that regeneration of mildly but also strongly degenerated disc tissue is possible.


Asunto(s)
Anillo Fibroso/metabolismo , Matriz Extracelular/metabolismo , Regulación de la Expresión Génica/genética , Degeneración del Disco Intervertebral/metabolismo , Desplazamiento del Disco Intervertebral/metabolismo , Disco Intervertebral/metabolismo , Anillo Fibroso/patología , Proteína Morfogenética Ósea 2/farmacología , Células Cultivadas , Matriz Extracelular/genética , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Disco Intervertebral/patología , Degeneración del Disco Intervertebral/genética , Degeneración del Disco Intervertebral/patología , Desplazamiento del Disco Intervertebral/genética , Desplazamiento del Disco Intervertebral/patología , Metaloproteinasa 1 de la Matriz/genética , Metaloproteinasa 1 de la Matriz/metabolismo , Metaloproteinasa 13 de la Matriz/genética , Metaloproteinasa 13 de la Matriz/metabolismo , Metaloproteinasa 3 de la Matriz/genética , Metaloproteinasa 3 de la Matriz/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , Regeneración/efectos de los fármacos , Regeneración/genética , Factor de Crecimiento Transformador beta1/farmacología , Factor de Necrosis Tumoral alfa/farmacología
13.
J Biomed Mater Res B Appl Biomater ; 108(3): 809-818, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31225700

RESUMEN

Since loss of meniscus is correlated with an increasing risk for osteoarthritis, meniscal scaffolds are proposed as new strategies. Development of a suitable scaffold has to take into account differing meniscus thickness, exposure to compressive and tensile forces combined with high porosity and biocompatibility of the material. After physical testing of three flat scaffolds composed of different modified polyglycolic acid (PGA) fibers, a three-dimensional meniscus-shaped PGA-hyaluronan implant was generated. Micro-computed tomography showed 90% porosity in the outer area with 50% in the inner area of the implant. Biocompatibility and expression of meniscus typical cartilaginous genes were shown for human meniscus cells cultivated in the implant with 10% human serum or 5% platelet-rich plasma for 14 days in vitro. The proof-of-concept study in sheep demonstrated proteoglycan- and collagen type I-rich repair tissue formation in partial meniscectomy combined with a meniscus-shaped PGA-hyaluronan implant after 6 months. In contrast, the control showed nearly no repair tissue formation. Thus, meniscus-shaped PGA-hyaluronan implants might be a suitable therapeutic approach to support repair tissue formation in partial meniscectomy.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/métodos , Materiales Biocompatibles/química , Menisco/trasplante , Ácido Poliglicólico/química , Andamios del Tejido/química , Anciano , Animales , Materiales Biocompatibles/metabolismo , Técnicas de Cultivo de Célula , Femenino , Regulación de la Expresión Génica , Humanos , Ácido Hialurónico/química , Ácido Hialurónico/metabolismo , Masculino , Pruebas Mecánicas , Menisco/citología , Regeneración , Ovinos , Factores de Tiempo , Ingeniería de Tejidos , Cicatrización de Heridas
14.
Cartilage ; 11(2): 192-202, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-29577749

RESUMEN

OBJECTIVE: The objective was to evaluate the proliferating, migratory and extracellular matrix (ECM) forming potential of annulus fibrosus cells derived from early (edAFC) or advanced (adAFC) degenerative tissue and their usability as a possible cell source for regenerative approaches for AF closure. DESIGN: EdAFC (n = 5 Pfirrman score of 2-3) and adAFC (n = 5 Pfirrman score of 4-5) were isolated from tissue of patients undergoing spine stabilizing surgery. Cell migration on stimulation with human serum (HS), platelet-rich plasma (PRP), and transforming growth factor ß-3 (TGFB3) was assessed by migration assay and proliferation was assessed on stimulation with HS. Induction of ECM synthesis was evaluated by gene expression analysis of AF-related genes in three-dimensional scaffold cultures that have been stimulated with 5% PRP or 10 ng/mL TGFB3 and histologically by collagen type I, type II, alcian blue, and safranin-O staining. RESULTS: EdAFC and adAFC were significantly attracted by 10% HS and 5% PRP. Additionally, both cell groups proliferated under stimulation with HS. Stimulation with 10 ng/mL TGFB3 showed significant induction of gene expression of collagen type II and aggrecan, while 5% PRP decreased the expression of collagen type I. Both cell groups showed formation of AF-like ECM after stimulation with TGFB3, whereas stimulation with PRP did not. CONCLUSIONS: Our study demonstrated that AF cells retain their potential for proliferation, migration, and ECM formation independent of the degeneration status of the tissue. Proliferation, migration, and ECM synthesis of the endogenous AF cells can be supported by different supplements. Hence, endogenous AF cells might be a suitable cell source for a regenerative repair approaches.


Asunto(s)
Anillo Fibroso/citología , Movimiento Celular/fisiología , Proliferación Celular/fisiología , Matriz Extracelular/metabolismo , Degeneración del Disco Intervertebral/patología , Células Cultivadas , Humanos , Disco Intervertebral/patología , Plasma Rico en Plaquetas/metabolismo , Regeneración/fisiología , Suero/metabolismo , Factor de Crecimiento Transformador beta3/administración & dosificación
15.
F1000Res ; 8: 842, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31354949

RESUMEN

The academic de.NBI Cloud offers compute resources for life science research in Germany.  At the beginning of 2017, de.NBI Cloud started to implement a federated cloud consisting of five compute centers, with the aim of acting as one resource to their users. A federated cloud introduces multiple challenges, such as a central access and project management point, a unified account across all cloud sites and an interchangeable project setup across the federation. In order to implement the federation concept, de.NBI Cloud integrated with the ELIXIR authentication and authorization infrastructure system (ELIXIR AAI) and in particular Perun, the identity and access management system of ELIXIR. The integration solves the mentioned challenges and represents a backbone, connecting five compute centers which are based on OpenStack and a web portal for accessing the federation.This article explains the steps taken and software components implemented for setting up a federated cloud based on the collaboration between de.NBI Cloud and ELIXIR AAI. Furthermore, the setup and components that are described are generic and can therefore be used for other upcoming or existing federated OpenStack clouds in Europe.


Asunto(s)
Disciplinas de las Ciencias Biológicas , Programas Informáticos , Alemania
16.
J Biomed Mater Res B Appl Biomater ; 107(8): 2649-2657, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-30860678

RESUMEN

To create artificial cartilage in vitro, mimicking the function of native extracellular matrix (ECM) and morphological cartilage-like shape is essential. The interplay of cell patterning and matrix concentration has high impact on the phenotype and viability of the printed cells. To advance the capabilities of cartilage bioprinting, we investigated different ECMs to create an in vitro chondrocyte niche. Therefore, we used methacrylated gelatin (GelMA) and methacrylated hyaluronic acid (HAMA) in a stereolithographic bioprinting approach. Both materials have been shown to support cartilage ECM formation and recovery of chondrocyte phenotype. We used these materials as bioinks to create cartilage models with varying chondrocyte densities. The models maintained shape, viability, and homogenous cell distribution over 14 days in culture. Chondrogenic differentiation was demonstrated by cartilage-typical proteoglycan and type II collagen deposition and gene expression (COL2A1, ACAN) after 14 days of culture. The differentiation pattern was influenced by cell density. A high cell density print (25 × 106 cells/mL) led to enhanced cartilage-typical zonal segmentation compared to cultures with lower cell density (5 × 106 cells/mL). Compared to HAMA, GelMA resulted in a higher expression of COL1A1, typical for a more premature chondrocyte phenotype. Both bioinks are feasible for printing in vitro cartilage with varying differentiation patterns and ECM organization depending on starting cell density and chosen bioink. The presented technique could find application in the creation of cartilage models and in the treatment of articular cartilage defects using autologous material and adjusting the bioprinted constructs size and shape to the patient. © 2019 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2649-2657, 2019.


Asunto(s)
Bioimpresión , Cartílago/metabolismo , Condrocitos/metabolismo , Gelatina/química , Ácido Hialurónico/química , Procesos Fotoquímicos , Impresión Tridimensional , Andamios del Tejido/química , Animales , Cartílago/citología , Condrocitos/citología , Ensayo de Materiales , Porcinos , Ingeniería de Tejidos
17.
J Tissue Eng Regen Med ; 13(4): 537-545, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30552734

RESUMEN

Plasma fibronectin (pFN) plays a crucial role in wound healing by binding to integrins and inducing cell migration. It is known to induce the migration and proliferation of mesenchymal progenitor cells in vitro, which play a key role during microfracture in cartilage repair. Endogenous chondrocytes from the native cartilage of the defect rim might aid in cartilage repair. In this study, the effect of pFN on proliferation, migration, and differentiation was tested on human articular chondrocytes. Results showed that treatment with pFN increased the migration of chondrocytes in a range of 1-30 µg/ml as tested with no effect on proliferation. TGFß3-induced chondrogenesis was not affected by pFN. Especially, gene expression of matrix metalloproteinases was not increased by pFN. Plasma FN fragmentation due to storage conditions could be excluded by SDS-PAGE. Moreover, bioactivity of pFN did not alter during storage at 4°C and 40°C for up to 14 days. Taken together, pFN induces the migration but not proliferation of human articular chondrocytes with no inhibitory effect on chondrogenic differentiation. Additionally, no loss of activity or fragmentation of pFN was observed after lyophilization and storage, making pFN an interesting bioactive factor for chondrocyte recruitment.


Asunto(s)
Cartílago Articular/citología , Diferenciación Celular , Movimiento Celular , Condrocitos/citología , Fibronectinas/sangre , Adulto , Diferenciación Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Condrocitos/efectos de los fármacos , Condrocitos/enzimología , Femenino , Fibronectinas/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Metaloproteinasas de la Matriz/metabolismo , Proteoglicanos/metabolismo
18.
Int J Mol Sci ; 19(8)2018 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-30060561

RESUMEN

Intervertebral disc degeneration is a major source of back pain. For intervertebral disc regeneration after herniation a fast closure of anulus fibrosus (AF) defects is crucial. Here, the use of the C-C motif chemokine ligand 25 (CCL)25 in comparison to differentiation factors such as transforming growth factor (TGF)ß3, bone morphogenetic protein (BMP)2, BMP7, BMP12, and BMP14 (all in concentrations of 10, 50 and 100 ng/mL) was tested in an in vitro micro mass pellet model with isolated and cultivated human AF-cells (n = 3) to induce and enhance AF-matrix formation. The pellets were differentiated (serum-free) with supplementation of the factors. After 28 days all used factors induced proteoglycan production (safranin O staining) and collagen type I production (immunohistochemical staining) in at least one of the tested concentrations. Histomorphometric scoring revealed that TGFß3 delivered the strongest induction of proteoglycan production in all three concentrations. Furthermore, it was the only factor able to facilitate collagen type II production, even higher than in native tissue samples. CCL25 was also able to induce proteoglycan and collagen type I production comparable to several BMPs. CCL25 could additionally induce migration of AF-cells in a chemotaxis assay and therefore possibly aid in regeneration processes after disc herniation by recruiting AF-cells.


Asunto(s)
Anillo Fibroso/citología , Anillo Fibroso/metabolismo , Movimiento Celular , Quimiocinas CC/metabolismo , Quimiotaxis , Matriz Extracelular/metabolismo , Proteínas Morfogenéticas Óseas/metabolismo , Células Cultivadas , Colágeno Tipo I/metabolismo , Humanos , Proteoglicanos/metabolismo , Factor de Crecimiento Transformador beta3/metabolismo
19.
J Stem Cells Regen Med ; 14(1): 45-52, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30018472

RESUMEN

Background: For regenerative therapies in the orthopedic field, one prerequisite for therapeutic success in the treatment of cartilage defects is the potential of body's own cells to migrate, proliferate and differentiate into functional cells. While this has been demonstrated for mesenchymal stem and progenitor cells (MPC) from healthy tissue sources, the potential of cells from degenerative conditions is unclear. In this study the regenerative potential of MPC derived from subchondral cancellous bone with diagnosed osteoarthritis is evaluated in vitro. Methods: OaMPC isolated from bone chips of three individual patients with Kellgren grade 3 osteoarthritis were characterized by analysis of cell surface antigen pattern. Cell proliferation was evaluated by doubling time and population doubling rate. Cell migration was assessed using a multi-well migration assay. Multi-lineage potential was evaluated by histological staining of adipogenic, osteogenic and chondrogenic markers. In addition, chondrogenic differentiation was verified by qPCR. Results: OaMPC showed a stable proliferation and a typical surface antigen pattern known from mesenchymal stem cells. Cell migration of oaMPC can be induced by human blood serum. OaMPC were capable of adipogenic, osteogenic and chondrogenic differentiation comparable to MPC derived from healthy conditions. Conclusion: OaMPC derived from knee joints affected by osteoarthritic conditions showed regeneration potential regarding migration, proliferation and chondrogenic differentiation. This suggests that oaMPC are able to contribute to cartilage repair tissue formation.

20.
Z Psychosom Med Psychother ; 64(2): 172-185, 2018 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-29862926

RESUMEN

OBJECTIVES: An evaluation of psychosocial functioning prior to lung transplantation is advisable for anticipating behavioral difficulties and for screening for any psychological distress that might be harmful to posttransplantation outcomes and adjustment. METHODS: In this cross-sectional, single-center study, the level of psychosocial functioning of N = 75 patients before lung transplantation was rated using the Transplant Evaluation Rating Scale (TERS). RESULTS: he reliability of the TERS total score was satisfactory at α = 0.75. A two-factorial solution (emotional sensitivity; defiance) was found. Higher TERS scores were significantly associated with higher depressive and anxiety symptoms (r = .38/r = .42), lower quality of life (r = -.26), and fewer years abstinent from smoking (r = -.35). No associations were found with lung disease and symptom severity. CONCLUSIONS: The TERS appears to be a reliable and valid measure with clinical utility for specifying behavioral concerns prior to lung transplantation.


Asunto(s)
Adaptación Psicológica , Trasplante de Corazón-Pulmón/psicología , Trasplante de Pulmón/psicología , Trastornos Mentales/diagnóstico , Selección de Paciente , Determinación de la Personalidad/estadística & datos numéricos , Ajuste Social , Adulto , Anciano , Trastornos de Ansiedad/diagnóstico , Trastornos de Ansiedad/psicología , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/psicología , Femenino , Humanos , Masculino , Tamizaje Masivo , Trastornos Mentales/psicología , Persona de Mediana Edad , Cooperación del Paciente/psicología , Psicometría/estadística & datos numéricos , Calidad de Vida/psicología , Reproducibilidad de los Resultados , Cese del Hábito de Fumar/psicología , Resultado del Tratamiento
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