Polycyclic aromatic hydrocarbons contaminants in black-lip (pearl) oyster Pinctada margaritifera from Kish Island (Persian Gulf)

Twenty-four Black-lip Oysters (Pinctada margaritifera ) were collected in summer (July) 2004 from six coastal locations in Kish Island (Persian Gulf) and were analyzed at the analytical laboratory of Great Lakes Institute for Environmental Research at the University of Windsor according to the chemical analysis procedures which has been accredited by the Canadian Association for Environmental Analysis Laboratories (CAEAL). In order to obtain information on bioavailability of sixteen EPA priority polycyclic aromatic hydrocarbons (PAHs), concentration of 2 to 6-ring PAHs was determined for all samples with application of a gas chromatograph with a mass selective detector. Oysters from Big Coral site exhibited a wide range of total PAH concentration (1.07 to 77.66 ng/g wet weight). The lowest value (oysters from Foreigner’s Pelage) and highest values were 0.7 and 36.33 ng/g wet weight respectively. Comparison of the PAH concentrations in oysters with sediments collected from the same locations showed that the overall bioaccumulation has been performed through the movement of water-soluble lower molecular weight (LMW) PAHs to the oysters in the studied area

Uveitis Associated with Monogenic Autoinflammatory Syndromes in Children

Monogenic autoinflammatory syndromes (MAISs), are caused by pathogenic genetic variants in the innate immune system, leading to dysregulation and aberrant inflammasome activation spontaneously or with minimal triggering. The diagnosis and treatment of MAISs can be intricate, relying on an increased recognition of potential differential diagnoses. This review examines the clinical features of MAIS, with a special focus on uveitis. It also evaluates treatment options and assesses the effects of activating molecular and cytokine pathways

Strategies for fast and low-dose laboratory-based phase contrast tomography for microstructural scaffold analysis in tissue engineering

The application of x-ray phase contrast computed tomography (PCT) to the field of tissue engineering is dis- cussed. Specific focus is on the edge illumination PCT method, which can be adapted to weakly coherent x-ray sources, permitting PCT imaging in standard (non-synchrotron) laboratory environments. The method was applied to a prominent research topic in tissue engineering, namely the development of effective and reliable decellularization protocols to derive scaffolds from native tissue. Results show that edge illumination PCT provides sufficient image quality to evaluate the microstructural integrity of scaffolds and, thus, to assess the performance of the used decellularization technique. In order to highlight that edge illumination PCT can ultimately comply with demands on a high specimen throughput and low doses of radiation, recently developed strategies for scan time and dose reduction are discussed

High contrast microstructural visualisation of natural acellular matrices by means of phase-based x-ray tomography

Acellular scaffolds obtained via decellularization are a key instrument in regenerative medicine both per se and to drive the development of future-generation synthetic scaffolds that could become available off-the-shelf. In this framework, imaging is key to the understanding of the scaffolds’ internal structure as well as their interaction with ells and other organs, including ideally post-implantation. Scaffolds of a wide range of intricate organs (oesophagus, lung, liver and small intestine) were imaged with x-ray phase contrast computed tomography (PC-CT). Image quality was sufficiently high to visualize scaffold micro architecture and to detect major anatomical features, such as the oesophageal mucosal-submucosal separation, pulmonary alveoli and intestinal villi. These results are a long-sought step for the field of regenerative medicine: until now, histology and scanning electron microscopy have been the gold standard to study the scaffold structure. However, they are both destructive: hence, they are not suitable for imaging scaffolds prior to transplantation, and have no prospect for post-transplantation use. PC-CT, on the other hand, is non-destructive, 3D and fully quantitative. Importantly, not only do we demonstrate achievement of high image quality at two different synchrotron facilities, but also with commercially available x-ray equipment, which makes the method instantly available worldwide to any research laboratory

Isolation of esophageal stem cells with potential for therapy.

Long-gap esophageal atresia represents a significant challenge for pediatric surgeons and current surgical approaches are associated with significant morbidity. A tissue-engineered esophagus, comprising cells seeded onto a scaffold, represents a therapeutic alternative. In this study, we aimed to determine the optimal techniques for isolation and culture of mouse esophageal epithelial cells and to isolate CD34-positive esophageal epithelial stem cells from cadaveric mouse specimens

Opportunities for phase-based computed tomography in the laboratory

It has been demonstrated in many instances that phase-based computed tomography (CT) can provide superior contrast-to-noise ratio for weakly attenuating samples than attenuation-based CT. In order to exploit this benefit on a wider scale, phase-based tomography implementations must be compatible with standard x-ray equipment. The edge illumination method, which is based on aperturing a beam and measuring spatial displacements caused by refraction, is an attractive choice for such use due to its low requirements on spatial and temporal coherence. This document provides a brief introduction to the working principle of the edge illumination method and reviews recent advances that lead to increased robustness, faster acquisitions and lower dose delivery. Moreover, it reports on a recent study in which the edge illumination method was applied to samples from the field of tissue engineering, yielding synchrotron-like image quality with exclusively commercially available, laboratory-based x-ray equipment

Decellularized human liver as a natural 3D-scaffold for liver bioengineering and transplantation

Liver synthetic and metabolic function can only be optimised by the growth of cells within a supportive liver matrix. This can be achieved by the utilisation of decellularised human liver tissue. Here we demonstrate complete decellularization of whole human liver and lobes to form an extracellular matrix scaffold with a preserved architecture. Decellularized human liver cubic scaffolds were repopulated for up to 21 days using human cell lines hepatic stellate cells (LX2), hepatocellular carcinoma (Sk-Hep-1) and hepatoblastoma (HepG2), with excellent viability, motility and proliferation and remodelling of the extracellular matrix. Biocompatibility was demonstrated by either omental or subcutaneous xenotransplantation of liver scaffold cubes (5 × 5 × 5 mm) into immune competent mice resulting in absent foreign body responses. We demonstrate decellularization of human liver and repopulation with derived human liver cells. This is a key advance in bioartificial liver development

Preservation of micro-architecture and angiogenic potential in a pulmonary acellular matrix obtained using intermittent intra-tracheal flow of detergent enzymatic treatment

Tissue engineering of autologous lung tissue aims to become a therapeutic alternative to transplantation. Efforts published so far in creating scaffolds have used harsh decellularization techniques that damage the extracellular matrix (ECM), deplete its components and take up to 5 weeks to perform. The aim of this study was to create a lung natural acellular scaffold using a method that will reduce the time of production and better preserve scaffold architecture and ECM components. Decellularization of rat lungs via the intratracheal route removed most of the nuclear material when compared to the other entry points. An intermittent inflation approach that mimics lung respiration yielded an acellular scaffold in a shorter time with an improved preservation of pulmonary micro-architecture. Electron microscopy demonstrated the maintenance of an intact alveolar network, with no evidence of collapse or tearing. Pulsatile dye injection via the vasculature indicated an intact capillary network in the scaffold. Morphometry analysis demonstrated a significant increase in alveolar fractional volume, with alveolar size analysis confirming that alveolar dimensions were maintained. Biomechanical testing of the scaffolds indicated an increase in resistance and elastance when compared to fresh lungs. Staining and quantification for ECM components showed a presence of collagen, elastin, GAG and laminin. The intratracheal intermittent decellularization methodology could be translated to sheep lungs, demonstrating a preservation of ECM components, alveolar and vascular architecture. Decellularization treatment and methodology preserves lung architecture and ECM whilst reducing the production time to 3 h. Cell seeding and in vivo experiments are necessary to proceed towards clinical translation

The Human Pancreas as a Source of Protolerogenic Extracellular Matrix Scaffold for a New-generation Bioartificial Endocrine Pancreas

OBJECTIVES: Our study aims at producing acellular extracellular matrix scaffolds from the human pancreas (hpaECMs) as a first critical step toward the production of a new-generation, fully human-derived bioartificial endocrine pancreas. In this bioartificial endocrine pancreas, the hardware will be represented by hpaECMs, whereas the software will consist in the cellular compartment generated from patient's own cells. BACKGROUND: Extracellular matrix (ECM)-based scaffolds obtained through the decellularization of native organs have become the favored platform in the field of complex organ bioengineering. However, the paradigm is now switching from the porcine to the human model. METHODS: To achieve our goal, human pancreata were decellularized with Triton-based solution and thoroughly characterized. Primary endpoints were complete cell and DNA clearance, preservation of ECM components, growth factors and stiffness, ability to induce angiogenesis, conservation of the framework of the innate vasculature, and immunogenicity. Secondary endpoint was hpaECMs’ ability to sustain growth and function of human islet and human primary pancreatic endothelial cells. RESULTS: Results show that hpaECMs can be successfully and consistently produced from human pancreata and maintain their innate molecular and spatial framework and stiffness, and vital growth factors. Importantly, hpaECMs inhibit human naïve CD4+ T-cell expansion in response to polyclonal stimuli by inducing their apoptosis and promoting their conversion into regulatory T cells. hpaECMs are cytocompatible and supportive of representative pancreatic cell types. DISCUSSION: We, therefore, conclude that hpaECMs has the potential to become an ideal platform for investigations aiming at the manufacturing of a regenerative medicine-inspired bioartificial endocrine pancreas