Transplantation of decellularized porcine kidney grafts repopulated with primary human cells demonstrates filtration function in pigs.

Background: End-stage renal disease is a growing global health issue, disproportionately impacting low- and middle-income countries. While kidney transplantation remains the best treatment for end-stage renal disease, access to this treatment modality is limited by chronic donor organ shortages. To address this critical need, we are developing transplantable bioengineered kidney grafts.

3D bioprinting of dynamic hydrogel bioinks enabled by small molecule modulators.

Three-dimensional bioprinting has emerged as a promising tool for spatially patterning cells to fabricate models of human tissue. Here, we present an engineered bioink material designed to have viscoelastic mechanical behavior, similar to that of living tissue. This viscoelastic bioink is cross-linked through dynamic covalent bonds, a reversible bond type that allows for cellular remodeling over time.

A resonant cavity system for exposing cell cultures to intense pulsed RF fields.

The IEEE and ICNIRP had specified a maximum permissible exposure for instantaneous peak electric field of 100 kV/m. However, no rationale was given for this limit. A novel exposure system was designed through a detailed process of analytical analysis, numerical modelling and prototype testing.

3D Bioprinting using UNIversal Orthogonal Network (UNION) Bioinks.

Three-dimensional (3D) bioprinting is a promising technology to produce tissue-like structures, but a lack of diversity in bioinks is a major limitation. Ideally each cell type would be printed in its own customizable bioink. To fulfill this need for a universally applicable bioink strategy, we developed a versatile, bioorthogonal bioink crosslinking mechanism that is cell compatible and works with a range of polymers.

Bioprinting Cell- and Spheroid-Laden Protein-Engineered Hydrogels as Tissue-on-Chip Platforms.

Human tissues, both in health and disease, are exquisitely organized into complex three-dimensional architectures that inform tissue function. In biomedical research, specifically in drug discovery and personalized medicine, novel human-based three-dimensional (3D) models are needed to provide information with higher predictive value compared to state-of-the-art two-dimensional (2D) preclinical models. However, current models remain inadequate to recapitulate the complex and heterogenous architectures that underlie biology.

3-Quinuclidinyl-α-methoxydiphenylacetate: A multi-targeted ligand with antimuscarinic and antinicotinic effects designed for the treatment of anticholinesterase poisoning.

Racemic 3-quinuclidinyl-α-methoxydiphenylacetate (MB266) was synthesised. Its activity at muscarinic acetylcholine receptors (mAChRs), and muscle and neuronal nicotinic acetylcholine receptors (nAChRs), was compared to that of atropine and racemic 3-quinucidinyl benzilate (QNB) using a functional assay based on agonist-induced elevation of intracellular calcium ion concentration in CN21, Chinese Hamster Ovary (CHO) and SHSY5Y human cell lines. MB266 acted as an antagonist at acetylcholine receptors, displaying 18-fold selectivity for mAChR versus nAChR (compared to the 15,200-fold selectivity observed for QNB).

Assessment of false transmitters as treatments for nerve agent poisoning.

Nerve agents inhibit acetylcholinesterase (AChE), leading to a build-up of acetylcholine (ACh) and overstimulation at cholinergic synapses. Current post-exposure nerve agent treatment includes atropine to treat overstimulation at muscarinic synapses, a benzodiazepine anti-convulsant, and an oxime to restore the function of AChE. Aside from the oxime, the components do not act directly to reduce the overstimulation at nicotinic synapses.

Bioprinting of stem cell expansion lattices.

Stem cells have great potential in regenerative medicine, with neural progenitor cells (NPCs) being developed as a therapy for many central nervous system diseases and injuries. However, one limitation to the clinical translation of stem cells is the resource-intensive, two-dimensional culture protocols required for biomanufacturing a clinically-relevant number of cells. This challenge can be overcome in an easy-to-produce and cost-effective 3D platform by bioprinting NPCs in a layered lattice structure.

Dynamic Hyaluronan Hydrogels with Temporally Modulated High Injectability and Stability Using a Biocompatible Catalyst.

Injectable and biocompatible hydrogels have become increasingly important for cell transplantation to provide mechanical protection of cells during injection and a stable scaffold for cell adhesion post-injection. Injectable hydrogels need to be easily pushed through a syringe needle and quickly recover to a gel state, thus generally requiring noncovalent or dynamic cross-linking. However, a dilemma exists in the design of dynamic hydrogels: hydrogels with fast exchange of cross-links are easier to eject using less force, but lack long-term stability; in contrast, slow exchange of cross-links improves stability, but compromises injectability and thus the ability to protect cells under flow.

Potency of irritation by benzylidenemalononitriles in humans correlates with TRPA1 ion channel activation.

We show that the physiological activity of solid aerosolized benzylidenemalononitriles (BMNs) including 'tear gas' (CS) in historic human volunteer trials correlates with activation of the human transient receptor potential ankyrin 1 ion channel (hTRPA1). This suggests that the irritation caused by the most potent of these compounds results from activation of this channel. We prepared 50 BMNs and measured their hTRPA1 agonist potencies.

Novel therapeutic strategies for acute lung injury induced by lung damaging agents: the potential role of growth factors as treatment options.

The increasing threat from terrorism has brought attention to the possible use of toxic industrial compounds (TICs) and other lung-damaging agents as weapons against civilian populations. The way in which these agents could be used favours the development of generic countermeasures. Improved medical countermeasures would increase survivability and improve the quality of recovery of lung damaged casualties.

The use of doxycycline as a protectant against sulphur mustard in HaCaT cells.

As part of an ongoing programme on medical countermeasures against the chemical warfare agent sulphur mustard (HD) and set against the background of the involvement of matrix metalloproteinases (MMPs) in the pathology of HD-induced vesication processes, the potentially beneficial effects of doxycycline on cell attachment was determined in confluent HaCaT cell cultures exposed to HD. Doxycycline was found to inhibit to a significant extent the tendency of HD-exposed cells to detach from the growth substrate, however, analysis of the metabolic activity of the adherent cells indicated that doxycycline treatment did not maintain cell viability. It was confirmed that apoptosis was the predominant mode of HD-induced cell death.

Utility of siRNA against Keap1 as a strategy to stimulate a cancer chemopreventive phenotype.

A duplex 21 nucleotide small interfering RNA (siRNA) against human Keap1 is described that represents a unique class of cancer chemopreventive agent. This siRNA can knockdown Keap1 mRNA and thereby relieve negative regulation of nuclear factor erythroid 2 p45-related factor 2 (Nrf2)-mediated gene expression. The siRNA lowered endogenous Keap1 mRNA to <30% of control levels between 24 and 72 h after transfection in human HaCaT keratinocyte cells and was capable of blocking ectopic expression of FLAG-tagged human Keap1 protein but not that of ectopic V5-tagged mouse Keap1 protein.

Effect of sulphur mustard on human skin cell lines with differential agent sensitivity.

The ability of sulphur mustard (HD) to induce DNA damage places limits on the efficacy of approaches aimed at protecting human cells from the cytotoxic effects of HD using a variety of protective agents such as thiol-containing esters and protease inhibitors. In the present study, potential alternative strategies were investigated by examining the differential effects of HD on G361, SVK14, HaCaT and NCTC 2544 human skin cells. The G361 cell line was more resistant to the cytotoxic effects of HD than the NCTC, HaCaT and SVK14 cell lines at HD doses of >3 and <100 microM HD as determined by the MTT assay.

Examination of changes in connective tissue macromolecular components of large white pig skin following application of Lewisite vapour.

The aim of this study was to provide information about the degradative processes that occur in major connective tissue components in skin following exposure of large white pigs to Lewisite vapour. Of particular interest were alterations in glycoproteins, which are known to mediate dermo-epidermal attachment (laminin and type IV collagen) and the main collagen found in the dermis (type III collagen). The immunostaining of transfer blots from skin extracts run on sodium dodecyl sulphate polyacrylamide gel electrophoresis gels revealed no evidence of cross-linking of laminin or of type III or IV collagen.

The development of tolerance to Clostridium perfringens type D epsilon-toxin in MDCK and G-402 cells.

The epithelial Madin Darby canine kidney (MDCK) cell line, Caucasian renal leiomyoblastoma (G-402) cells, human small airways epithelial (HSAE) cells, human bronchial epithelial (HBE) cells and human renal proximal tubule (HRPT) epithelial cells were examined for sensitivity to Clostridium perfringens biotype D epsilon-toxin. MDCK and G-402 cells were confirmed as being the only established cell lines that are sensitive to the toxin. HSAE, HBE and HRPT epithelial cells were only found to be sensitive to the toxin at concentrations of > 1 mg/ mL.