The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human ...counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing.
This article presents the results of the combined effects of RGD (arginine–glycine–aspartate) functionalization and mechanical stimulation on osteogenesis that could lead to the development of ...implantable robust tissue‐engineered mineralized constructs. Porous polycaprolactone/hydroxyapatite (PCL/HA) scaffolds are functionalized with RGD‐C (arginine–glycine–aspartate–cysteine) peptide. The effects of RGD functionalization are then explored on human fetal osteoblast cell adhesion, proliferation, osteogenic differentiation (alkaline phosphatase activity), extracellular matrix (ECM) production, and mineralization over 28 days. The effects of RGD functionalization followed by mechanical stimulation with a cyclic fluid shear stress of 3.93 mPa in a perfusion bioreactor are also elucidated. The tensile properties (Young's moduli and ultimate tensile strengths) of the cell‐laden scaffolds are measured at different stages of cell culture to understand how the mechanical properties of the tissue‐engineered structures evolve. RGD functionalization is shown to promote initial cell adhesion, proliferation, alkaline phosphatase (ALP) activity, and ECM production. However, it does not significantly affect mineralization and tensile properties. Mechanical stimulation after RGD functionalization is shown to further improve the ALP activity, ECM production, mineralization, and tensile properties, but not cell proliferation. The results suggest that combined RGD functionalization and mechanical stimulation of cell‐laden PCL/HA scaffolds can be used to accelerate the regeneration of robust bioengineered bone structures.
Low- and middle-income countries have tremendous potential for renewable energy production, including production of renewable carbon from locally prolific crops. In this work, bamboo endemic to West ...Africa (Bambusa vulgaris) was studied as a feedstock for the production of renewable sugars as the gateway to the local production of biofuels and bio-based chemical products. The effectiveness of delignification and amorphization pretreatments was evaluated, with the observation that quantitative (97 ± 4%) sugar yields could be obtained with a rapid initial hydrolysis rate (82 ± 4 mg g−1 h−1) but only when amorphization was performed following delignification. Experimental measurements and further characterization using 13C solid state nuclear magnetic resonance (NMR) helped establish the importance of amorphization and delignification and explained why the order of these treatments determined their effectiveness. The economics of the bamboo-based process were compared with those projected for corn stover, selected as a well-studied benchmark crop. Because of the higher bamboo growth rate compared with corn stover and the effectiveness of the pretreatment, the projected net present value (NPV) of the bamboo biorefinery was positive ($190 MM, U.S.), whereas the corn biorefinery projected to negative NPV (−$430 MM, U.S.). A socially sustainable framework for deployment of a bamboo biorefinery in a low- or middle-income economy was then proposed, guided by the principle of local ownership and stakeholder buy-in. The findings presented here motivate further investment in development of bamboo cultivation and conversion to sugars as a rapid route to decarbonization of low- and middle-income economies.
The paper presents the results of the experimental and analytical study of targeted drug-loaded polymer-based microspheres made from blend polymer of polylactic-co-glycolic acid and polycaprolactone ...(PLGA-PCL) for targeted and localized cancer drug delivery. In vitro sustained release with detailed thermodynamically driven drug release kinetics, over a period of three months using encapsulated targeted drugs (prodigiosin-EphA2 or paclitaxel-EphA2) and control drugs Prodigiosin (PGS), and paclitaxel (PTX) were studied. Results from in vitro study showed a sustained and localized drug release that is well-characterized by non-Fickian Korsmeyer–Peppas kinetics model over the range of temperatures of 37 °C (body temperature), 41 °C, and 44 °C (hyperthermic temperatures). The in vitro alamar blue, and flow cytometry assays in the presence of the different drug-loaded polymer formulations resulted to cell death and cytotoxicity that was evidence through cell inhibition and late apoptosis on triple negative breast cancer (TNBC) cells (MDA-MB 231). In vivo studies carried out on groups of 4-week-old athymic nude mice that were induced with subcutaneous TNBC, showed that the localized release of the EphA2-conjugated drugs was effective in complete elimination of residual tumor after local surgical resection. Finally, ex vivo histopathological analysis carried out on the euthanized mice revealed no cytotoxicity and absence of breast cancer metastases in the liver, kidney, and lungs 12 weeks after treatment. The implications of the results are then discussed for the development of encapsulated EphA2-conjugated drugs formulation in the specific targeting, localized, and sustain drug release for the elimination of local recurred TNBC tumors after surgical resection.
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•An evaluation of 106 parameter configurations for spray coating PSCs on efficiency.•Regression modeling of the relationship between processing parameters and PCE.•Polynomial models ...yielding results hinting to the possibility of PCE as high as 29%.•A Mark R-CNN identifying deformations in PSC structures with a precision of 83.3%.
Low-cost perovskite solar cells (PSCs) have experienced unprecedented gains in power conversion efficiency (PCE) of up to 25% of lab-scale devices. To be realized in the market, however, PSCs are not only required to be efficient but also scalable in production. While spray coating has viability as an industrial manufacturing process for perovskite photovoltaics scaling, optimizing the spray conditions is often seen as a challenging and time-consuming process due to its complex and multidimensional parameters. Herein, we use a machine learning (ML) approach to capture the relationship between spray parameter settings to the resultant photoconversion efficiency (PCE) of PSCs from experimental collected data points. This data-driven approach has the potential to accurately predict PCE values given the manufacturing parameters, enabling optimization and resulting in an increased experimentally recorded PCE. Furthermore, we also used a Convolutional Neural Network (CNN) to predict defect size distributions in the PSC structures to improve the understanding of defect formation mechanism at given spray parameters. The implications of the results are discussed for optimizing spray manufacturing process of efficient perovskite photovoltaics.
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In this paper, we use Polyethylene Oxide (PEO) particles to control the morphology of Formamidinium (FA)-rich perovskite films and achieve large grains with improved optoelectronic ...properties. Consequently, a planar perovskite solar cell (PSC) is fabricated with additions of 5 wt% of PEO, and the highest PCE of 18.03% was obtained. This solar cell is also shown to retain up to 80% of its initial PCE after about 140 h of storage under the ambient conditions (average relative humidity of 62.5 ± 3.25%) in an unencapsulated state. Furthermore, the steady-state PCE of the PEO-modified PSC device remained stable for long (over 2500 s) under continuous illumination. This addition of PEO particles is shown to enable the tuning of the optoelectronic properties of perovskite films, improvements in the overall photophysical properties of PSCs, and an increase in resistance to the degradation of PSCs.
An improved understanding of the evolution of cell structure and viscoelasticity with cancer malignancy could enable the development of a new generation of biomarkers and methods for cancer ...diagnosis. Hence, in this study, we present the viscoelastic properties (moduli and viscosities) and the actin cytoskeletal structures of triple negative breast cancer (TNBC) cells with different metastatic potential. These include: MCF-10A normal breast cells (studied as a control); MDA-MB-468 cells (less metastatic TNBC cells), and MDA-MB-231 cells (highly metastatic TNBC cells). A combination of shear assay and digital imaging correlation (DIC) techniques is used to measure the local viscoelastic properties of live breast cells subjected to constant shear stress. The local moduli and viscosities of the nuclei and cytoplasm are characterized using a generalized Maxwell model, which is used to determine the time-dependent creep responses of cells. The nuclei are shown to be stiffer and more viscous than the cytoplasms of the normal breast cells and TNBC cells. The MCF-10A normal breast cells are found to be twice as stiff as the less metastatic MDA-MB-468 breast cancer cells and over ten times stiffer than the highly metastatic MDA-MB-231 breast cancer cells. Similar trends are also observed in the viscosities of the nuclei and the cytoplasms. The measured differences in cell viscoelastic properties are also associated with significant changes in the cell cytoskeletal structure, which is studied using confocal fluorescence microscopy. This reveals significant differences in the levels of actin expression and organization in TNBC cells as they become highly metastatic. Our results suggest that the shear assay measurements of cell viscoelastic properties may be used as effective biomarkers for TNBC diagnosis and screening.
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•Combined shear assay and DIC method can measure local cell viscoelasticity.•TNBC cells can be differentiated from normal breast cells based on viscoelasticity.•TNBC cell viscoelasticity correlates with their actin cytoskeletal structure.•Shear assay and DIC approaches provides new insights for TNBC screening.
This study presents a combined experimental and analytical study of the fracture behavior and toughening mechanisms of bioprocessed mycelium-based biocomposites. The composites comprise hemicellulose ...hemp ducts (as nutritional and reinforcing components) intertwined with increasing weight percentages of laterite particles. Single-edge notched fracture experiments and in-situ observations of crack growth were used to explore the effects of varying proportions of laterite on the composite resistance-curve behavior. The toughening mechanisms, fracture modes, and crack-microstructure interactions were also elucidated. Since crack-bridging and crack-deflection were observed to be the dominant toughening mechanisms, they were modeled using fracture mechanics approaches. Crack-bridging was shown to dominate the toughening at lower weight fractions of laterite (0–20 wt%). However, as the laterite content increases (20–40 wt%), a combination of crack-bridging and crack-deflection was observed. Finally, at higher laterite weight fractions (>40 wt%), crack-tip shielding occurred primarily via crack deflection. The fracture mechanics predictions of resistance-curve behavior are shown to be consistent with the experimental measurements. The results suggest that mycelium-based and mycelium-laterite composites can be engineered with tunable fracture toughness. The implications of the results are also discussed for the development of sustainable building materials.
AbstractIn this paper, the removal mechanisms of organic (e.g., nitrate) and inorganic (e.g., lead) contaminants were investigated in ceramic water filters with organic (i.e., activated carbon) and ...inorganic (i.e., hydroxyapatite) additives. The ceramic water filters were characterized using atomic force microscopy, nitrogen sorption analysis, X-ray pair distribution function analysis, and scanning electron microscopy. It was found that adhesion controlled the efficiency of the ceramic water filters in the removal of contaminants. The conventional ceramic water filters had no adhesive interactions with the contaminants. A small amount of contaminants was removed by physical trapping in the pores. However, the addition of organic additives increased the adhesion between the organic contaminants and ceramic water filters (i.e., from 16 to 170 nN). This resulted in an increase of the efficiency from 0.9 to 6.7 mg·g−1 in the removal of nitrate for a 20 wt.% addition of activated carbon. The removal of nitrate was completed once the surface was fully covered (surface adsorption mechanism). It was limited by the specific surface area of the materials. On the other hand, the inorganic additives increased the adhesive interactions of the ceramic water filters with the inorganic contaminants (i.e., from 33 to 153 nN). The efficiency in the removal of lead increased from 12.2 to 67.1 mg·g−1 with a 2 wt.% addition of hydroxyapatite. The removal was achieved by substitution of lead atoms (Pb) for calcium atoms (Ca) in the hydroxyapatite. Hence, the novelty of this work lies in the fact that doped ceramic water filters remove a wide range of contaminants from water via the combination of trapping, adsorption, and substitution mechanisms. Such filters are also suitable in terms of mechanical performances (i.e., 8.7 MPa) for application in household water treatment.
Irregular biomechanics are a hallmark of cancer biology subject to extensive study. The mechanical properties of a cell are similar to those of a material. A cell's resistance to stress and strain, ...its relaxation time, and its elasticity are all properties that can be derived and compared to other types of cells. Quantifying the mechanical properties of cancerous (malignant) versus normal (non-malignant) cells allows researchers to further uncover the biophysical fundamentals of this disease. While the mechanical properties of cancer cells are known to consistently differ from the mechanical properties of normal cells, a standard experimental procedure to deduce these properties from cells in culture is lacking. This paper outlines a procedure to quantify the mechanical properties of single cells in vitro using a fluid shear assay. The principle behind this assay involves applying fluid shear stress onto a single cell and optically monitoring the resulting cellular deformation over time. Cell mechanical properties are subsequently characterized using digital image correlation (DIC) analysis and fitting an appropriate viscoelastic model to the experimental data generated from the DIC analysis. Overall, the protocol outlined here aims to provide a more effective and targeted method for the diagnosis of difficult-to-treat cancers.
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