Humanized celiac-prone epithelium in vitro express MHC-II and co-stimulatory molecules necessary for gluten peptide presentation

Background: The role intestinal epithelial cells (IECs) play in the breakdown of tolerance to gluten at an early stage in celiac disease (CeD) is unclear. Epithelial stress is a feature of CeD, and although the triggers are largely unknown, it is accompanied by expression of several markers that could be involved in initiation of inflammatory responses. IECs have been shown to express MHC class II (MHC-II) molecules and participate in antigen presentation in several models. Whether IECs can participate in gluten peptide presentation, the major environmental trigger in celiac disease, is unknown. To study this, a model expressing human MHC-II, HLA DQ8 or HLADQ2, would be required. Aims: To develop organoid monolayers from transgenic mice expressing human celiac risk genes: HLA-DQ8 and -DQ2. To investigate conditions leading to the induction of epithelial MHC-II and its main co-stimulatory molecules, CD80, CD86 and CD40, that could enable early gluten peptide presentation.Instituto de Estudios Inmunológicos y Fisiopatológico

The Fabrication and Bonding of Thermoplastic Microfluidics: A Review

Various fields within biomedical engineering have been afforded rapid scientific advancement through the incorporation of microfluidics. As literature surrounding biological systems become more comprehensive and many microfluidic platforms show potential for commercialization, the development of representative fluidic systems has become more intricate. This has brought increased scrutiny of the material properties of microfluidic substrates. Thermoplastics have been highlighted as a promising material, given their material adaptability and commercial compatibility. This review provides a comprehensive discussion surrounding recent developments pertaining to thermoplastic microfluidic device fabrication. Existing and emerging approaches related to both microchannel fabrication and device assembly are highlighted, with consideration toward how specific approaches induce physical and/or chemical properties that are optimally suited for relevant real-world applications

Self-Cleaning Ceramic Tiles Produced via Stable Coating of TiO2 Nanoparticles

The high photocatalytic power of TiO2 nanoparticles has drawn great attention in environmental and medical applications. Coating surfaces with these particles enables us to benefit from self-cleaning properties and decomposition of pollutants. In this paper, two strategies have been introduced to coat ceramic tiles with TiO2 nanoparticles, and the self-cleaning effect of the surfaces on degradation of an organic dye under ultraviolent (UV) exposure is investigated. In the first approach, a simple one-step heat treatment method is introduced for coating, and different parameters of the heat treatment process are examined. In the second method, TiO2 nanoparticles are first aminosilanized using (3-Aminopropyl)triethoxysilane (APTES) treatment followed by their covalently attachment onto CO2 plasma treated ceramic tiles via N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) and N-Hydroxysuccinimide (NHS) chemistry. We monitor TiO2 nanoparticle sizes throughout the coating process using dynamic light scattering (DLS) and characterize developed surfaces using X-ray photoelectron spectroscopy (XPS). Moreover, hydrophilicity of the coated surfaces is quantified using a contact angle measurement. It is shown that applying a one-step heat treatment process with the optimum temperature of 200 °C for 5 h results in successful coating of nanoparticles and rapid degradation of dye in a short time. In the second strategy, the APTES treatment creates a stable covalent coating, while the photocatalytic capability of the particles is preserved. The results show that coated ceramic tiles are capable of fully degrading the added dyes under UV exposure in less than 24 h

Phage display for the detection, analysis, disinfection, and prevention of Staphylococcus aureus

Abstract The World Health Organization has designated Staphylococcus aureus as a global health concern. This designation stems from the emergence of multiple drug‐resistant strains that already account for hundreds of thousands of deaths globally. The development of novel treatment strategies to eradicate S. aureus or mitigate its pathogenic potential is desperately needed. In the effort to develop emerging strategies to combat S. aureus, phage display is uniquely positioned to assist in this endeavor. Leveraging bacteriophages, phage display enables researchers to better understand interactions between proteins and their antagonists. In doing so, researchers have the capacity to design novel inhibitors, biosensors, disinfectants, and immune modulators that can target specific S. aureus strains. In this review, we highlight how phage display can be leveraged to design novel solutions to combat S. aureus. We further discuss existing uses of phage display as a detection, intervention, and prevention platform against S. aureus and provide outlooks on how this technology can be optimized for future applications

Self-assembling nanofibrous bacteriophage microgels as sprayable antimicrobials targeting multidrug-resistant bacteria

Abstract Nanofilamentous bacteriophages (bacterial viruses) are biofunctional, self-propagating, and monodisperse natural building blocks for virus-built materials. Minifying phage-built materials to microscale offers the promise of expanding the range function for these biomaterials to sprays and colloidal bioassays/biosensors. Here, we crosslink half a million self-organized phages as the sole structural component to construct each soft microgel. Through an in-house developed, biologics-friendly, high-throughput template method, over 35,000 phage-built microgels are produced from every square centimetre of a peelable microporous film template, constituting a 13-billion phage community. The phage-exclusive microgels exhibit a self-organized, highly-aligned nanofibrous texture and tunable auto-fluorescence. Further preservation of antimicrobial activity was achieved by making hybrid protein-phage microgels. When loaded with potent virulent phages, these microgels effectively reduce heavy loads of multidrug-resistant Escherichia coli O157:H7 on food products, leading to up to 6 logs reduction in 9 hours and rendering food contaminant free

Sentinel Wraps: Real-Time Monitoring of Food Contamination by Printing DNAzyme Probes on Food Packaging

Here, we report the development of a transparent, durable, and flexible sensing surface that generates a fluorescence signal in the presence of a specific target bacterium. This material can be used in packaging, and it is capable of monitoring microbial contamination in various types of food products in real time without having to remove the sample or the sensor from the package. The sensor was fabricated by covalently attaching picoliter-sized microarrays of an E. coli-specific RNA-cleaving fluorogenic DNAzyme probe (RFD-EC1) to a thin, flexible, and transparent cyclo-olefin polymer (COP) film. Our experimental results demonstrate that the developed (RFD-EC1)-COP surface is specific, stable for at least 14 days under various pH conditions (pH 3–9), and can detect E. coli in meat and apple juice at concentrations as low as 10³ CFU/mL. Furthermore, we demonstrate that our sensor is capable of detecting bacteria while still attached to the food package, which eliminates the need to manipulate the sample. The developed biosensors are stable for at least the shelf life of perishable packaged food products and provide a packaging solution for real-time monitoring of pathogens. These sensors hold the potential to make a significant contribution to the ongoing efforts to mitigate the negative public-health-related impacts of food-borne illnesses

Highly Stable Hierarchically Structured All-Polymeric Lubricant-Infused Films Prevent Thrombosis and Repel Multidrug-Resistant Pathogens

Thrombus formation and infections caused by bacterial adhesion are the most common causes of failure in blood-contacting medical devices. Reducing the interaction of pathogens using repellent surfaces has proven to be a successful strategy in preventing device failure. However, designing scale-up methodologies to create large-scale repellent surfaces remains challenging. To address this need, we have created an all-polymeric lubricant-infused system using an industrially viable swelling-coagulation solvent (S-C) method. This induces hierarchically structured micro/nano features onto the surface, enabling improved lubricant infusion. Poly(3,3,3-trifluoropropylmethylsiloxane) (PTFS) was used as the lubricant of choice, a previously unexplored omniphobic nonvolatile silicone oil. This resulted in all-polymeric liquid-infused surfaces that are transparent and flexible with long-term stability. Repellent properties have been demonstrated using human whole blood and methicillin-resistant Staphylococcus aureus (MRSA) bacteria matrices, with lubricated surfaces showing 93% reduction in blood stains and 96.7% reduction in bacterial adherence. The developed material has the potential to prevent blood and pathogenic contamination for a range biomedical devices within healthcare settings.E.A. thanks Spanish Ministry of Science and Innovation for the FPI Grant (BES-2017-080057). T.F.D. acknowledges support from NSERC Discovery Grant, Ontario Early Researcher Award and McMaster Start-up funds to T.F.D. T.F.D and Z.H.D are Tier II Canada Research Chairs

Mature induced-pluripotent-stem-cell-derived human podocytes reconstitute kidney glomerular-capillary-wall function on a chip

An in vitro model of the human kidney glomerulus — the major site of blood filtration — could facilitate drug discovery and illuminate kidney-disease mechanisms. Microfluidic organ-on-a-chip technology has been used to model the human proximal tubule, yet a kidney-glomerulus-on-a-chip has not been possible because of the lack of functional human podocytes — the cells that regulate selective permeability in the glomerulus. Here, we demonstrate an efficient (> 90%) and chemically defined method for directing the differentiation of human induced pluripotent stem (hiPS) cells into podocytes that express markers of the mature phenotype (nephrin+, WT1+, podocin+, Pax2−) and that exhibit primary and secondary foot processes. We also show that the hiPS-cell-derived podocytes produce glomerular basement-membrane collagen and recapitulate the natural tissue/tissue interface of the glomerulus, as well as the differential clearance of albumin and inulin, when co-cultured with human glomerular endothelial cells in an organ-on-a-chip microfluidic device. The glomerulus-on-a-chip also mimics adriamycin-induced albuminuria and podocyte injury. This in vitro model of human glomerular function with mature human podocytes may facilitate drug development and personalized-medicine applications

Improved treatment of systemic blood infections using antibiotics with extracorporeal opsonin hemoadsorption

Here we describe development of an extracorporeal hemoadsorption device for sepsis therapy that employs commercially available polysulfone or polyethersulfone hollow fiber filters similar to those used clinically for hemodialysis, covalently coated with a genetically engineered form of the human opsonin Mannose Binding Lectin linked to an Fc domain (FcMBL) that can cleanse a broad range of pathogens and endotoxin from flowing blood without having to first determine their identity. When tested with human whole blood in vitro, the FcMBL hemoadsorption filter (FcMBL-HF) produced efficient (90-99%) removal of Gram negative (Escherichia coli) and positive (Staphylococcus aureus) bacteria, fungi (Candida albicans) and lipopolysaccharide (LPS)-endotoxin. When tested in rats, extracorporeal therapy with the FcMBL-HF device reduced circulating pathogen and endotoxin levels by more than 99%, and prevented pathogen engraftment and inflammatory cell recruitment in the spleen, lung, liver and kidney when compared to controls. Studies in rats revealed that treatment with bacteriocidal antibiotics resulted in a major increase in the release of microbial fragments or ???pathogen-associated molecular patterns??? (PAMPs) in vivo, and that these PAMPs were efficiently removed from blood within 2 h using the FcMBL-HF; in contrast, they remained at high levels in animals treated with antibiotics alone. Importantly, cleansing of PAMPs from the blood of antibiotic-treated animals with the FcMBL-hemoadsorbent device resulted in reduced organ pathogen and endotoxin loads, suppressed inflammatory responses, and resulted in more stable vital signs compared to treatment with antibiotics alone. As PAMPs trigger the cytokine cascades that lead to development of systemic inflammatory response syndrome and contribute to septic shock and death, co-administration of FcMBL-hemoadsorption with antibiotics could offer a more effective approach to sepsis therapy.ope