A Fully Integrated Microfluidic Device with Immobilized Dyes for Simultaneous Detection of Cell-Free DNA and Histones from Plasma Using Dehydrated Agarose Gates.

Sepsis, a life-threatening condition resulting from a failing host response to infection, causes millions of deaths annually, necessitating rapid and simple prognostic assessments. A variety of genomic and proteomic biomarkers have been developed for sepsis. For example, it has been shown that the level of plasma cell-free DNA (cfDNA) and circulating histones increases considerably during sepsis, and they are linked with sepsis severity and mortality. Developing a diagnostic tool that is capable of assessing such diverse biomarkers is challenging as the detection methodology is quite different for each. Here, a fully integrated microfluidic device capable of detecting a genomic biomarker (cfDNA) and a proteomic biomarker (total circulating histones) using a common detection platform has been demonstrated. The microfluidic device utilizes dehydrated agarose gates loaded with pH-specific agarose to electrophoretically trap cfDNA and histones at their respective isoelectric points. It also incorporates fluorescent dyes within the device, eliminating the need for off-chip sample preparation and allowing the direct testing of plasma samples without the need for labeling DNA and histones with fluorescent dyes beforehand. Xurography, which is a low-cost and rapid method for fabrication of microfluidics, is used in all the fabrication steps. Experimental results demonstrate the effective accumulation and separation of cfDNA and histones in the agarose gates in a total processing time of 20 min, employing 10 and 30 Volts for cfDNA and histone accumulation and detection, respectively. The device can potentially be used to distinguish between the survivors and non-survivors of sepsis. The integration of the detection of both biomarkers into a single device and dye immobilization enhances its clinical utility for rapid point-of-care assessment of sepsis prognosis.

Isoelectric trapping and discrimination of histones from plasma in a microfluidic device using dehydrated isoelectric gate.

Histones are basic proteins with an isoelectric point around 11. It has been shown that the level of plasma circulating histones increases significantly during sepsis, and circulating free histones are associated with sepsis severity and mortality. It was found that the median plasma total free histone concentration of sepsis ICU non-survivors is higher compared to survivors. Therefore, histone concentration can serve as a prognostic indicator and there is a need for a simple, low-cost, and rapid method for measuring histone levels. In this work, we have developed a microfluidic device containing an isoelectric membrane made of dehydrated agarose gel of a specific pH embedded in a porous membrane for isoelectric trapping of histones rapidly. Although isoelectric gates have been used for trapping proteins before, they have to be introduced at the time of the experiment. Here, we show that isoelectric gates formed by gels loaded in a scaffold can be integrated directly into the fabrication process flow, dehydrated for storage, and rehydrated during the experiment and still function effectively to achieve isoelectric trapping. A low-cost and rapid microfabrication technique, xurography, was used for agarose integration and device fabrication. The integrated device was tested with samples containing buffered histone, histone in the presence of high-concentration bovine serum albumin (BSA), and histone spiked in blood plasma. The results show that the device can be used to distinguish between survivors and non-survivors of sepsis in less than 10 min, making it suitable as a point-of-care device for sepsis prognosis.

Identification and Quantification of Aqueous Disinfectants Using an Array of Carbon Nanotube-Based Chemiresistors.

Disinfection of water is essential to prevent the growth of pathogens, but at high levels, it can cause harm to human health. Therefore, accurate monitoring of disinfectant concentrations in water is essential to ensure safe drinking water. The use of multiple disinfectants at different stages in water treatment plants makes it necessary to also identify the type and concentrations of all of the disinfectant species present. Here, we demonstrate an effective approach to identify and quantify multiple disinfectants (using the example of free chlorine and potassium permanganate) in water using single-walled carbon nanotube (SWCNT)-based reagent-free chemiresistive sensing arrays. Facile fabrication of chemiresistive devices makes them a popular choice for the implementation of sensor arrays. Our sensing array consists of functionalized and unfunctionalized (blank) SWCNT sensors to distinguish the disinfectants. The distinct responses from the different sensors at varying concentrations and pH can be fitted to the mathematical model of a Langmuir adsorption isotherm separately for each sensor. Blank and functionalized sensors respond through different mechanisms that result in varying responses that are concentration- and pH-dependent. Chemometric techniques such as principal component analysis (PCA) and partial least-squares-discriminant analysis (PLS-DA) were used to analyze the sensor data. PCA showed an excellent separation of the analytes over five different pHs (5.5, 6.5, 7.5, 8.5, and 9.5). PLS-DA provided excellent separability as well as good predictability with a Q2 of 94.26% and an R2 of 95.67% for the five pH regions of the two analytes. This proof-of-concept solid-state chemiresistive sensing array can be developed for specific disinfectants that are commonly used in water treatment plants and can be deployed in water distribution and monitoring facilities. We have demonstrated the applicability of chemiresistive devices in a sensor array format for the first time for aqueous disinfectant monitoring.

Three-dimensional oxygen concentration monitoring in hydrogels using low-cost phosphorescence lifetime imaging for tissue engineering.

Oxygen concentration measurement in 3D hydrogels is vital in 3D cell culture and tissue engineering. However, standard 3D imaging systems capable of measuring oxygen concentration with adequate precision are based on advanced microscopy platforms, which are not accessible in many laboratories due to the system's complexity and the high price. In this work, we present a fast and low-cost phosphorescence lifetime imaging design for measuring the lifetime of oxygen-quenched phosphorescence emission with 0.25 µs temporal precision and sub-millimeter spatial resolution in 3D. By combining light-sheet illumination and the frequency-domain lifetime measurement using a commercial rolling-shutter CMOS camera in the structure of a conventional optical microscope, this design is highly customizable to accommodate application-specific research needs while also being low-cost as compared to advanced instruments. As a demonstration, we made a fluidic device with a gas-permeable film to create an artificial oxygen gradient in the hydrogel sample. Dye-embedded beads were distributed in the hydrogel to conduct continuous emission lifetime monitoring when nitrogen was pumped through the fluidic channel and changed oxygen distribution in the sample. The dynamics of the changes in lifetime co-related with their location in the gel of size 0.5 mm×1.5 mm×700 µm demonstrate the ability of this design to measure the oxygen concentration stably and precisely in 3D samples.

Impact of 3D collagen-based model and hydrostatic pressure on periodontal ligament fibroblast: A morpho-biochemical analysis.

This study developed a customized hydrostatic pressure-based loading environment to investigate the effect of static hydrostatic pressure on the periodontal ligament fibroblasts (PDLf) in a three-dimensional (3D) collagen-based model. The cylindrical tissue constructs were comprised of PDL fibroblast cells seeded in type I collagen matrices and divided into three experimental groups: Control (no load), low-load (∼0.07 kPa), and high-load (∼60 kPa), all subjected to 24 h of experimental duration. Cells in the 3D construct were stained with fluorophore-conjugated antibodies for cytoskeletal protein F-actin and matricellular protein periostin. Cell culture supernatant was assessed for receptor activator of nuclear factor kappaB ligand (RANKL) and osteoprotegerin (OPG) expression. Transmission electron microscopy examined the contact between the cells and the collagen matrix. Ultrastructural changes in the 3D collagen matrix were also analyzed using scanning electron microscopy. Experiments were performed in triplicates, and data was analyzed using one-way ANOVA (p < 0.05). The 3D PDLf constructs from the low-load group demonstrated the highest levels of homogeneous cell distribution and higher expression of F-actin and periostin with enhanced interaction with the matrix. The collagen matrix in this group showed more closely packed fibers forming thicker bundles when compared to the control and the high-load 3D PDLf constructs. Nonuniform cell distribution with decreased expression of F-actin and periostin was observed in the control and high-load PDLf constructs. The high-load group showed the highest RANKL/OPG expression. This study demonstrated low-level hydrostatic pressure's role in regulating PDLf functions and extracellular matrix response, while excessive hydrostatic pressure may be detrimental to PDL fibroblast cell function.

A reagent-free phosphate chemiresistive sensor using carbon nanotubes functionalized with crystal violet.

Phosphate is important for plant and animal growth. Therefore, it is commonly added as a fertilizer in agricultural fields. Phosphorus is typically measured using colorimetric or electrochemical sensors. Colorimetric sensors suffer from a limited measuring range and toxic waste generation while electrochemical sensors suffer from long-term drifts due to reference electrodes. Here, we propose a solid-state, reagent-free and reference electrode-free chemiresistive sensor for measuring phosphate using single-walled carbon nanotubes functionalized with crystal violet. The functionalized sensor exhibited a measuring range from 0.1 mM to 10 mM at pH 8. No significant interference was observed for common interfering anions like nitrates, sulphates, and chlorides. This study showed a proof-of-concept chemiresistive sensor, which can potentially be used to measure phosphate levels in hydroponics and aquaponics systems. The dynamic measuring range further needs to be extended for surface water samples.

Advancing our understanding of bioreactors for industrial-sized cell culture: health care and cellular agriculture implications.

Bioreactors are advanced biomanufacturing tools that have been widely used to develop various applications in the fields of health care and cellular agriculture. In recent years, there has been a growing interest in the use of bioreactors to enhance the efficiency and scalability of these technologies. In cell therapy, bioreactors have been used to expand and differentiate cells into specialized cell types that can be used for transplantation or tissue regeneration. In cultured meat production, bioreactors offer a controlled and efficient means of producing meat without the need for animal farming. Bioreactors can support the growth of muscle cells by providing the necessary conditions for cell proliferation, differentiation, and maturation, including the provision of oxygen and nutrients. This review article aims to provide an overview of the current state of bioreactor technology in both cell therapy and cultured meat production. It will examine the various bioreactor types and their applications in these fields, highlighting their advantages and limitations. In addition, it will explore the future prospects and challenges of bioreactor technology in these emerging fields. Overall, this review will provide valuable insights for researchers and practitioners interested in using bioreactor technology to develop innovative solutions in the biomanufacturing of therapeutic cells and cultured meat.

Solid-state, reagent-free and one-step laser-induced synthesis of graphene-supported metal nanocomposites from metal leaves and application to glucose sensing.

The laser-induced method to prepare three-dimensional (3D) porous graphene has been widely used in many fields owing to its low-cost, easy operation, maskless patterning and ease of mass production. Metal nanoparticles are further introduced on the surface of 3D graphene to enhance its property. The existing methods, however, such as laser irradiation and electrodeposition of metal precursor solution, suffer from many shortcomings, including complicated procedure of metal precursor solution preparation, strict experimental control, and poor adhesion of metal nanoparticles. Herein, a solid-state, reagent-free, and one-step laser-induced strategy has been developed for the fabrication of metal nanoparticle modified-3D porous graphene nanocomposites. Commercial transfer metal leaves were covered on a polyimide film followed by direct laser irradiation to produce 3D graphene nanocomposites modified with metal nanoparticles. The proposed method is versatile and applicable to incorporate various metal nanoparticles including gold silver, platinum, palladium, and copper. Furthermore, the 3D graphene nanocomposites modified with AuAg alloy nanoparticles were successfully synthesized in both 21 Karat (K) and 18K gold leaves. Its electrochemical characterization demonstrated that the synthesized 3D graphene-AuAg alloy nanocomposites exhibited excellent electrocatalytic properties. Finally, we fabricated LIG-AuAg alloy nanocomposites as enzyme-free flexible sensors for glucose detection. The LIG-18K electrodes exhibited the superior glucose sensitivity of 1194 µA mM-1 cm-2 and low detection limits of 0.21 µM. The LIG-21K nanocomposite sensors showed two linear ranges from 1 µM to 1 mM and 2 mM-20 mM with good sensitivity. Furthermore, the flexible glucose sensor showed good stability, sensitivity, and ability to sense in blood plasma samples. The proposed one-step fabrication of reagent-free and metal alloy nanoparticles on LIG with excellent electrochemical performance opens up possibilities for diversifying potential applications of sensing, water treatment and electrocatalysis.

Efficient, Breathable, and Compostable Multilayer Air Filter Material Prepared from Plant-Derived Biopolymers.

State-of-art face masks and respirators are fabricated as single-use devices using microfibrous polypropylene fabrics, which are challenging to be collected and recycled at a community scale. Compostable face masks and respirators can offer a viable alternative to reducing their environmental impact. In this work, we have developed a compostable air filter produced by electrospinning a plant-derived protein, zein, on a craft paper-based substrate. The electrospun material is tailored to be humidity tolerant and mechanically durable by crosslinking zein with citric acid. The electrospun material demonstrated a high particle filtration efficiency (PFE) of 91.15% and a high pressure drop (PD) of 191.2 Pa using an aerosol particle diameter of 75 ± 2 nm at a face velocity of 10 cm/s. We deployed a pleated structure to reduce the PD or improve the breathability of the electrospun material without compromising the PFE over short- and long-duration tests. Over a 1 h salt loading test, the PD of a single-layer pleated filter increased from 28.9 to 39.1 Pa, while that of the flat sample increased from 169.3 to 327 Pa. The stacking of pleated layers enhanced the PFE while retaining a low PD; a two-layer stack with a pleat width of 5 mm offers a PFE of 95.4 ± 0.34% and a low PD of 75.2 ± 6.1 Pa.

Red blood cell dynamics in extravascular biological tissues modelled as canonical disordered porous media.

The dynamics of blood flow in the smallest vessels and passages of the human body, where the cellular character of blood becomes prominent, plays a dominant role in the transport and exchange of solutes. Recent studies have revealed that the microhaemodynamics of a vascular network is underpinned by its interconnected structure, and certain structural alterations such as capillary dilation and blockage can substantially change blood flow patterns. However, for extravascular media with disordered microstructure (e.g. the porous intervillous space in the placenta), it remains unclear how the medium's structure affects the haemodynamics. Here, we simulate cellular blood flow in simple models of canonical porous media representative of extravascular biological tissue, with corroborative microfluidic experiments performed for validation purposes. For the media considered here, we observe three main effects: first, the relative apparent viscosity of blood increases with the structural disorder of the medium; second, the presence of red blood cells (RBCs) dynamically alters the flow distribution in the medium; third, symmetry breaking introduced by moderate structural disorder can promote more homogeneous distribution of RBCs. Our findings contribute to a better understanding of the cell-scale haemodynamics that mediates the relationship linking the function of certain biological tissues to their microstructure.

Integration of hydrogels into microfluidic devices with porous membranes as scaffolds enables their drying and reconstitution.

Hydrogels are a critical component of many microfluidic devices. They have been used in cell culture applications, biosensors, gradient generators, separation microdevices, micro-actuators, and microvalves. Various techniques have been utilized to integrate hydrogels into microfluidic devices such as flow confinement and gel photopolymerization. However, in these methods, hydrogels are typically introduced in post processing steps which add complexity, cost, and extensive fabrication steps to the integration process and can be prone to user induced variations. Here, we introduce an inexpensive method to locally integrate hydrogels into microfluidic devices during the fabrication process without the need for post-processing. In this method, porous and fibrous membranes such as electrospun membranes are used as scaffolds to hold gels and they are patterned using xurography. Hydrogels in various shapes as small as 200 µm can be patterned using this method in a scalable manner. The electrospun scaffold facilitates drying and reconstitution of these gels without loss of shape or leakage that is beneficial in a number of applications. Such reconstitution is not feasible using other hydrogel integration techniques. Therefore, this method is suitable for long time storage of hydrogels in devices which is useful in point-of-care (POC) devices. This hydrogel integration method was used to demonstrate gel electrophoretic concentration and quantification of short DNA (150 bp) with different concentrations in rehydrated agarose embedded in electrospun polycaprolactone (PCL) membrane. This can be developed further to create a POC device to quantify cell-free DNA, which is a prognostic biomarker for severe sepsis patients.

Microfluidic device for single step measurement of protein C in plasma samples for sepsis prognosis.

Protein C is a vitamin K dependant protein in plasma that plays an essential role in regulating the coagulation cascade and inflammatory response. As a result of its importance in these roles, it has been suggested as a biomarker for prognosis of patients affected by sepsis. Sepsis is a dysregulated host response to an infection that is the leading cause of mortality in U.S. hospitals and results in the highest cost of hospitalization. It was found that protein C concentration in non-surviving sepsis patients is significantly lower (1.8 µg mL-1) than in survivors and healthy patients who have a protein C concentration of 3.9-5.9 µg mL-1. Current methods for diagnosing sepsis rely on expensive immunoassays or functional assays that require multiple steps for isolation and activation of protein C. We demonstrate in this paper a low cost, single step assay for detection of protein C in blood plasma. This was done by combining isoelectric gates with barium-immobilized metal affinity trapping. The electric field was optimized for use with immobilized metal affinity using COMSOL simulation. The integrated device was tested with samples containing buffered protein C, protein C in the presence of high concentration bovine serum albumin and alpha 1-proteinase inhibitor, and in blood plasma with spiked protein C. The stability of the measured values was tested by monitoring the intensity of a mixture of protein C with BSA and A1PI every minute to determine that measurement after 40 minutes was optimal. The results showed that the device could be used to distinguish a reduction in protein C from 4.46 µg mL-1 to 1.96 µg mL-1 with greater than 98% confidence in plasma making it suitable for sepsis prognosis.

Defect Density-Dependent pH Response of Graphene Derivatives: Towards the Development of pH-Sensitive Graphene Oxide Devices.

In this study, we demonstrate that a highly pH-sensitive substrate could be fabricated by controlling the type and defect density of graphene derivatives. Nanomaterials from single-layer graphene resembling a defect-free structure to few-layer graphene and graphene oxide with high defect density were used to demonstrate the pH-sensing mechanisms of graphene. We show the presence of three competing mechanisms of pH sensitivity, including the availability of functional groups, the electrochemical double layer, and the ion trapping that determines the overall pH response. The graphene surface was selectively functionalized with hydroxyl, amine, and carboxyl groups to understand the role and density of the graphene pH-sensitive functional groups. Later, we establish the development of highly pH-sensitive graphene oxide by controlling its defect density. This research opens a new avenue for integrating micro-nano-sized pH sensors based on graphene derivatives into next-generation sensing platforms.

Deciphering Stem Cell From Apical Papilla-Macrophage Choreography Using a Novel 3-dimensional Organoid System.

INTRODUCTION: Immune cell-mesenchymal stem cell crosstalk modulates the process of repair and regeneration. In this study, a novel heterogeneous cell containing a matrix-based 3-dimensional (3D) tissue construct was used to study the interactions between stem cells from apical papilla (SCAPs) and macrophage for a comprehensive understanding on the cellular signaling mechanisms guiding inflammation and repair. METHODS: SCAPs and macrophages were seeded with collagen in 3D-printed molds to generate self-assembled tissue constructs, which were exposed to 3 conditions: no stimulation, lipopolysaccharide (LPS), and interleukin (IL)-4 from 0 to 14 days. Specimens from each group were evaluated for cellular interactions, inflammatory mediators (IL-1ß, tumor necrosis factor [TNF]-α, macrophage-derived chemokine [MDC], macrophage inflammatory protein [MIP]-1ß, monocyte chemoattractant protein [MCP]-1, IL-6, IL-8, transforming growth factor [TGF]-ß1, IL-1RA, IL-10), expression of surface markers (CD80, 206), transcription factors (pSTAT1, pSTAT6), and SCAP differentiation markers (dentin sialophosphoprotein [DSPP], dentin matrix acidic phosphoprotein 1 [DMP-1], and alizarin red) using confocal laser scanning microscopy and multiplex cytokine profiling from 2 to 14 days. RESULTS: SCAP and macrophages displayed a cytokine-mediated interaction and differentiation characteristics. The increased pro-inflammatory cytokines/chemokines, IL-1ß, TNF-α, MDC, and MIP-1ß, in the earlier phase followed by the higher ratio of pSTAT6/pSTAT1 and decreased CD206 (P < .05), indicated a distinct polarization behavior in macrophages during repair in the LPS group. Conversely, the equal ratio of pSTAT6/pSTAT1, late increase in CD206, and amplified secretion of IL-1RA, IL-10, and TGF-ß1 (P < .05) in the anti-inflammatory environment, directed alternative macrophage polarization, promoting SCAP differentiation and tissue modeling in IL-4 group. CONCLUSIONS: The novel 3D organoid system developed in this study allowed a comprehensive analysis of the SCAP-macrophage interactions during inflammation and healing, providing a deeper insight on the periapical dynamics of the immature tooth.

Single-step measurement of cell-free DNA for sepsis prognosis using a thread-based microfluidic device.

Cell-free DNA (cfDNA) content in plasma has been studied as a biomarker for sepsis. Recent publications show that the cfDNA content in sepsis patients entering intensive care unit who were likely to survive had a total cfDNA concentration of 1.16 ± 0.13 µg/mL compared to 4.65 ± 0.48 µg/mL of non-survivors. Current methods for measuring cfDNA content in plasma were designed to amplify and measure low concentrations of specific DNA, making them unsuitable for low-cost measurement of total cfDNA content in plasma. Here, we have developed a point of care (POC) device that uses a thread silicone device as a medium to store a fluorescent dye which eliminates the need for preparatory steps, external aliquoting and dispensing of reagents, preconcentration, and external mixing while reducing the detection cost. The device was paired with a portable imaging system with an excitation filter at 472 ± 10 nm and an emission filter of 520 ± 10 nm that can be operated with just 100 mA current supply. The device was demonstrated for use in the quantification of buffered cfDNA samples in a range 1-6 µg/mL with a sensitivity of 5.72 AU/µg/mL and with cfDNA spiked in plasma with a range of 1-3 µg/mL and a sensitivity of 5.43 AU/µg/mL. The results showed that the device could be used as a low-cost, rapid, and portable POC device for differentiating between survivors and non-survivors of sepsis within 20 min.

High-resolution fabrication of nanopatterns by multistep iterative miniaturization of hot-embossed prestressed polymer films and constrained shrinking.

The fabrication of nanostructures and nanopatterns is of crucial importance in microelectronics, nanofluidics, and the manufacture of biomedical devices and biosensors. However, the creation of nanopatterns by means of conventional nanofabrication techniques such as electron beam lithography is expensive and time-consuming. Here, we develop a multistep miniaturization approach using prestressed polymer films to generate nanopatterns from microscale patterns without the need of complex nanolithography methods. Prestressed polymer films have been used as a miniaturization technique to fabricate features with a smaller size than the initial imprinted features. However, the height of the imprinted features is significantly reduced after the thermal shrinking of the prestressed films due to the shape memory effect of the polymer, and as a result, the topographical features tend to disappear after shrinking. We have developed a miniaturization approach that controls the material flow and maintains the shrunken patterns by applying mechanical constraints during the shrinking process. The combination of hot embossing and constrained shrinking makes it possible to reduce the size of the initial imprinted features even to the nanoscale. The developed multistep miniaturization approach allows using the shrunken pattern as a master for a subsequent miniaturization cycle. Well-defined patterns as small as 100 nm are fabricated, showing a 10-fold reduction in size from the original master. The developed approach also allows the transfer of the shrunken polymeric patterns to a silicon substrate, which can be used as a functional substrate for many applications or directly as a master for nanoimprint lithography.

Engineering a Novel Stem Cells from Apical Papilla-Macrophages Organoid for Regenerative Endodontics.

INTRODUCTION: A 3-dimensional (3D) tissue construct with a heterogeneous cell population is critical to understand the interactions between immune cells and stem cells from the apical papilla (SCAPs) in the periapical region for developing treatment strategies in regenerative endodontics. This study aimed to develop and characterize a 3D tissue construct with a binary cell system for studying the interactions between SCAPs and macrophages in the presence of lipopolysaccharide (proinflammatory) and interleukin 4 (anti-inflammatory) environments. METHODS: SCAPs and macrophages were seeded in the 3D-printed dumbbell-shaped molds to generate tissue constructs with a binary cell population. Two experimental (lipopolysaccharide and interleukin 4) and control (non-stimulation) conditions were applied to the tissue constructs to determine the characteristics of the tissue construct, the volume of viable cells, and their morphology using confocal laser scanning microscopy from a 0- to 7-day period. Experiments were conducted in triplicate, and data were analyzed with trend analysis and 2-way analysis of variance at a significance of P < .05. RESULTS: The tissue constructs revealed distinct SCAP-macrophage interaction in pro/anti-inflammatory environments. SCAPs displayed characteristic self-organization as a cap-shaped structure in the tissue construct. The growth of cells and cell-to-cell and cell-to-matrix interactions resulted in 70% and 30% decreased dimension of the tissue graft on the SCAP side and macrophage side, respectively, at day 7 (P < .0001). The tissue environments influenced SCAP-macrophage interactions, resulting in an altered viable cell volume (P < .05), morphology, and structural organization. CONCLUSIONS: This study developed and characterized an apical papilla organoid in a 3D collagen-based tissue construct for studying SCAP-macrophage crosstalk in tissue regeneration as well as repair.

Engineering Murine Adipocytes and Skeletal Muscle Cells in Meat-like Constructs Using Self-Assembled Layer-by-Layer Biofabrication: A Platform for Development of Cultivated Meat.

Global meat consumption has been growing on a per capita basis over the past 20 years resulting in ever-increasing devotion of resources in the form of arable land and potable water to animal husbandry which is unsustainable and inefficient. One approach to meet this insatiable demand is to use biofabrication methods used in tissue engineering in order to make skeletal muscle tissue-like constructs known as cultivated meat to be used as a food source. Here, we demonstrate the use of a scaffold-free biofabrication method that forms cell sheets composed of murine adipocytes and skeletal muscle cells and assembles these sheets in parallel to create a 3D meat-like construct without the use of any exogenous materials. This layer-by-layer self-assembly and stacking process is fast (4 days of culture to form sheets and few hours for assembly) and scalable (stable sheets with diameters >3 cm are formed). Tissues formed with only muscle cells were equivalent to lean meat with comparable protein and fat contents (lean beef had 1.5 and 0.9 times protein and fat, respectively, as our constructs) and incorporating adipocyte cells in different ratios to myoblasts and/or treatment with different media cocktails resulted in a 5% (low fat meat) to 35% (high fat meat) increase in the fat content. Not only such constructs can be used as cultivated meat, they can also be used as skeletal muscle models.

Potential role of blood biomarkers in patients with fibromyalgia: a systematic review with meta-analysis.

ABSTRACT: Fibromyalgia (FM) is a complex chronic pain condition. Its symptoms are nonspecific, and to date, no objective test exists to confirm FM diagnosis. Potential objective measures include the circulating levels of blood biomarkers. This systematic review and meta-analysis aim to review studies assessing blood biomarkers' levels in patients with FM compared with healthy controls. We systematically searched the PubMed, MEDLINE, EMBASE, and PsycINFO databases. Fifty-four studies reporting the levels of biomarkers in blood in patients with FM were included. Data were extracted, and the methodological quality was assessed independently by 2 authors. The methodological quality of 9 studies (17%) was low. The results of most studies were not directly comparable given differences in methods and investigated target immune mediators. Thus, data from 40 studies only were meta-analyzed using a random-effects model. The meta-analysis showed that patients with FM had significantly lower levels of interleukin-1 ß and higher levels of IL-6, IL-8, tumor necrosis factor-alpha, interferon gamma, C-reactive protein, and brain-derived neurotrophic factor compared with healthy controls. Nevertheless, this systematic literature review and meta-analysis could not support the notion that these blood biomarkers are specific biomarkers of FM. Our literature review, however, revealed that these same individual biomarkers may have the potential role of identifying underlying pathologies or other conditions that often coexist with FM. Future research is needed to evaluate the potential clinical value for these biomarkers while controlling for the various confounding variables.

Defect Engineering of Graphene to Modulate pH Response of Graphene Devices.

Graphene-based pH sensors are a robust, durable, sensitive, and scalable approach for the sensitive detection of pH in various environments. However, the mechanisms through which graphene responds to pH variations are not well-understood yet. This study provides a new look into the surface science of graphene-based pH sensors to address the existing gaps and inconsistencies among the literature concerning sensing response, the role of defects, and surface/solution interactions. Herein, we demonstrate the dependence of the sensing response on the defect density level of graphene, measured by Raman spectroscopy. At the crossover point (ID/IG = 0.35), two countervailing mechanisms balance each other out, separating two regions where either a surface defect induced (negative slope) or a double layer induced (positive slope) response dominates. For ratios above 0.35, the pH-dependent induction of charges at surface functional groups (both pH-sensitive and nonsensitive groups) dominates the device response. Below a ratio of 0.35, the response is dominated by the modulation of charge carriers in the graphene due to the electric double layer formed from the interaction between the graphene surface and the electrolyte solution. Selective functionalization of the surface was utilized to uncover the dominant acid-base interactions of carboxyl and amine groups at low pH while hydroxyl groups control the high pH range sensitivity. The overall pH-sensing characteristics of the graphene will be determined by the balance of these two mechanisms.