Tendon injuries are frequent and occur in the elderly, young, and athletic populations. The inadequate number of donors combined with many challenges associated with autografts, allografts, ...xenografts, and prosthetic devices have added to the value of engineering biological substitutes, which can be implanted to repair the damaged tendons. Electrospun scaffolds have the potential to mimic the native tissue structure along with desired mechanical properties and, thus, have attracted noticeable attention. In order to improve the biological responses of these fibrous structures, we designed and fabricated 3D multilayered composite scaffolds, where an electrospun nanofibrous substrate was coated with a thin layer of cell-laden hydrogel. The whole construct composition was optimized to achieve adequate mechanical and physical properties as well as cell viability and proliferation. Mesenchymal stem cells (MSCs) were differentiated by the addition of bone morphogenetic protein 12 (BMP-12). To mimic the natural function of tendons, the cell-laden scaffolds were mechanically stimulated using a custom-built bioreactor. The synergistic effect of mechanical and biochemical stimulation was observed in terms of enhanced cell viability, proliferation, alignment, and tenogenic differentiation. The results suggested that the proposed constructs can be used for engineering functional tendons.
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IJS, KILJ, NUK, PNG, UL, UM
Denture adhesives are widely used to avoid the detachment and sliding of dentures. However, the adhesion properties can be affected by variation in mouth conditions such as the level of salivation. ...The objective of this study was to understand the effect of environmental conditions on the adhesion properties of a commercially available denture adhesive named as Poligrip® Free manufactured by GlaxoSmithKline Ltd., UK and to identify the reasons for the observed variation in its adhesion strength.
The failure mechanisms of denture adhesive have been assessed through using different physical, mechanical and thermal characterization experiments. All methods were used in different pH, temperatures, and salivation conditions and at the end, a strategy was proposed to overcome the failure of the paste in hyposalivation as well.
In vitro models mimicking the denture gingival interface were designed to evaluate the adhesion properties of the investigated adhesive. Changes in the adhesion strength in response to three major factors related to the oral conditions including level of salivation, pH, and temperature were measured. The results of lap shear, tensile test, and internal interactions suggested a cohesion failure, where the lowest adhesion strength was due to hyposalivation. Fourier transform infrared spectroscopy (FTIR) and rheological analysis confirmed the importance of hydrogen bonds and hydration in the adhesion strength of the paste.
The investigated scenarios are widely observed in patient using denture adhesives and the clinical reports have indicated the inconsistency in adhesion strength of the commercial products. After identifying the potential reasons for such behavior, methods such as the addition of tripropylene glycol methyl ether (TPME) to enhance internal hydrogen bonds between the polymers are proposed to improve adhesion in the hyposalivation scenario.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Chitin and lignin primarily accumulate as bio-waste resulting from byproducts of crustacean crusts and plant biomass. Recently, their use has been proposed for diverse and unique bioengineering ...applications, amongst others. However, their weak mechanical properties need to be improved in order to facilitate their industrial utilization. In this paper, we fabricated hybrid fibers composed of a chitin-lignin (CL)-based sol-gel mixture and elastomeric poly (glycerol sebacate) (PGS) using a standard electrospinning approach. Obtained results showed that PGS could be coherently blended with the sol-gel mixture to form a nanofibrous scaffold exhibiting remarkable mechanical performance and improved antibacterial and antifungal activity. The developed hybrid fibers showed promising potential in advanced biomedical applications such as wound care products. Ultimately, recycling these sustainable biopolymers and other bio-wastes alike could propel a "greener" economy.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Textile technologies in which fibers containing biological factors and cells are formed and assembled into constructs with biomimetic properties have attracted significant attention in the field of ...tissue engineering. This Forum article highlights the most prominent advances of the field in the areas of fiber fabrication and construct engineering.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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Native tissues orchestrate their functions by complex interdependent cascades of biochemical and biophysical cues that vary spatially and temporally during cellular processes. ...Scaffolds with well-tuned structural, mechanical, and biochemical properties have been developed to guide cell behavior and provide insight on cell-matrix interaction. However, static scaffolds very often fail to mimic the dynamicity of native extracellular matrices. Stimuli-responsive scaffolds have emerged as powerful platforms that capture vital features of native tissues owing to their ability to change chemical and physical properties in response to cytocompatible stimuli, thus enabling on-demand manipulation of cell microenvironment. The vast expansion in biorthogonal chemistries and stimuli-responsive functionalities has fuelled further the development of new smart scaffolds that can permit multiple irreversible or reversible spatiotemporal modulation of cell-directing cues, thereby prompting in-depth studies to interpret the decisive elements that regulate cell behavior. Integration of stimuli-responsive hydrogels with current biofabrication technologies has allowed the development of dynamic scaffolds with organizational features and hierarchical architectures similar to native tissues. This review highlights the progress achieved using stimuli-responsive hydrogels in fundamental cell biology studies, with particular emphasis on the interplay between chemistry, biomaterials design, and biofabrication technologies for manipulation of cell microenvironment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Hydrogel optical fibers are utilized for continuous glucose sensing in real time. The hydrogel fibers consist of poly(acrylamide‐co‐poly(ethylene glycol) diacrylate) cores functionalized with ...phenylboronic acid. The complexation of the phenylboronic acid and cis‐diol groups of glucose enables reversible changes of the hydrogel fiber diameter. The analyses of light propagation loss allow for quantitative glucose measurements within the physiological range.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Textile technologies in which fibers containing biological factors and cells are formed and assembled into constructs with biomimetic properties have attracted significant attention in the field of ...tissue engineering. This Forum article highlights the most prominent advances of the field in the areas of fiber fabrication and construct engineering.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
A novel and innovative approach to develop reduction of graphene oxide (GO) solution for fabrication of highly and truly transparent conductive electrode (TCE) has been presented. Thanks to ...outstanding mechanical and electronic properties of graphene which offer practical applications in synthesizing composites as well as fabricating various optoelectronic devices, in this study, conductive reduced graphene oxide (r-GO) thin films were prepared through sequential chemical and thermal reduction process of homogeneously dispersed GO solutions. The conductivity and transparency of r-GO thin film is regulated using hydroiodic acid (HI) as reducing agent following by vacuum thermal annealing. The prepared r-GO is characterized by XRD, AFM, UV–vis and Raman spectroscopy. the AFM topographic images reveal surface roughness almost ∼11 nm which became less than 2 nm for the 4 mg/mL solution. Moreover, XRD analysis and Raman spectra substantiate the interlayer spacing between rGO layers has been reduced dramatically and also electronic conjugation has been ameliorated after using HI chemical agent and 700 °C thermal annealing sequentially. Subsequently providing r-GO transparent electrode with decent and satisfactory transparency, acceptable conductivity and suitable work function, it has been exploited as the anode in organic light emitting diode (OLED). The maximum luminance efficiency and maximum power efficiency reached 4.2 cd/A and 0.83 lm/W, respectively. We believe that by optimizing the hole density, sheet resistance, transparency and surface morphology of the r-GO anodes, the device efficiencies can be remarkably increased further.
•A novel process for reduction of Graphene Oxide (GO) thin films has been proposed.•GO thin films reduced by chemical agent and thermal annealing shows low sheet resistance and high transparency.•A Transparent Conductive Electrode (TCE) was fabricated through the GO thin film to apply in optoelectronic devices.•The GO thin film has been characterized by AFM, XRD, Raman analysis and UV-Visible spectra.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The current research presents using a nanocomposite comprising of a cationic conjugated polyelectrolyte (CPE), poly(2,5-bis(2-(N,N-diethylammonium bromide)ethoxy)-1,4-phenylene)-alt-1,4-phenylene ...or (PPPNEt2·HBr), with graphene oxide (GO) as a new hole injection layer (HIL) for organic light emitting diodes. It is demonstrated that using the designed ionically functionalized water-soluble conjugated polymers instead of polyethylene dioxythiophene:polystyrenesulfonate (PEDOT:PSS) is a promising approach to overcome the strong acidic nature of PEDOT:PSS besides excluding its nonconductive PSS part. As the other aspiration of this work, we introduce a good partner for dissolving and spin-casting of GO as a simple and economic technique to use the hole conductive and electron blocking nature of GO in the hole injection portion of assembled devices. Using this new binary blend showed enhanced charge carrier mobility, good electroluminescence, and J–V characteristics in comparison with conventional devices. Such improvement is interpreted with induced ion space charge of HIL at the interface and resulting electric field screening effect due to ion migration.
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IJS, KILJ, NUK, PNG, UL, UM
Engineering tissue-like scaffolds that can mimic the microstructure, architecture, topology, and mechanical properties of native tissues while offering an excellent environment for cellular growth ...has remained an unmet need. To address these challenges, multicompartment composite fibers are fabricated. These fibers can be assembled through textile processes to tailor tissue-level mechanical and electrical properties independent of cellular level components. Textile technologies also allow control of the distribution of different cell types and the microstructure of fabricated constructs and the direction of cellular growth within the 3D microenvironment. Here, we engineered composite fibers from biocompatible cores and biologically relevant hydrogel sheaths. The fibers are mechanically robust to being assembled using textile processes and could support adhesion, proliferation, and maturation of cell populations important for the engineering of skeletal muscles. We also demonstrated that the changes in the coating of the multicompartment fibers could potentially enhance myogenesis in vitro.
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IJS, KILJ, NUK, PNG, UL, UM
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