1,720,985 research outputs found
Thermo-responsive properties of methylcellulose hydrogels for cell sheet engineering
Full text linkMethylcellulose (MC) hydrogels change their affinity to water depending on their temperature and can thus be used as substrates for cell sheet engineering. In this work, we characterize the thermo-responsive properties of 8% w/v MC hydrogels, produced in two saline solutions (i.e., Na2SO4 and phosphate buffered saline) at different concentrations, by investigating the rheological properties and the UV-absorbance in function of temperature. Both rheological and UV-spectroscopy tests showed that the addition of salts to MC hydrogels allowed lowering the LCST of the MC hydrogel; moreover, hydrogels produced in 0.1 M Na2SO4 or PBS 20 g/L were proved to be particularly promising for cell sheet engineering application, showing a LCST below 37 degrees C
Polyurethane foam scaffolds: a novel 3D in vitro model for breast cancer-derived bone metastasis
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Novel class of collector in electrospinning device for the fabrication of 3D nanofibrous structure for large defect load-bearing tissue engineering application
No full textAdequate porosity, appropriate pore size, and 3D-thick shape are crucial parameters in the design of scaffolds, as they should provide the right space for cell adhesion, spreading, migration, and growth. In this work, a novel design for fabricating a 3D nanostructured scaffold by electrospinning was taken into account. Helical spring-shaped collector was purposely designed and used for electrospinning PCL fibers. Improved morphological properties and more uniform diameter distribution of collected nanofibers on the turns of helical spring-shaped collector are confirmed by SEM analysis. SEM images elaboration showed 3D pores with average diameter of 4 and 5.5 micrometer in x-y plane and z-direction, respectively. Prepared 3D scaffold possessed 99.98% porosity which led to the increased water uptake behavior in PBS at 37°C up to 10 days, and higher degradation rate compared to 2D flat structure. Uniaxial compression test on 3D scaffolds revealed an elastic modulus of 7 MPa and a stiffness of 102 MPa, together with very low hysteresis area and residual strain. In vitro cytocompatibility test with MG-63 osteoblast-like cells using AlamarBlueTM colorimetric assay, indicated a continuous increase in cell viability for the 3D structure over the test duration. SEM observation showed enhanced cells spreading and diffusion into the underneath layers for 3D scaffold. Accelerated calcium deposition in 3D substrate was confirmed by EDX analysis. Obtained morphological, physical, and mechanical properties together with in vitro cytocompatibility results, suggest this novel technique as a proper method for the fabrication of 3D nanofibrous scaffolds for the regeneration of critical-size load bearing defects
Hybrid polyurethane scaffolds interpenetrated with newly cross-linked gelatin for adipose tissue regeneration
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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