Key environmental stress biomarker candidates for the optimisation of chemotherapy treatment of leukaemia

The impact of fluctuations of environmental parameters such as oxygen and starvation on the evolution of leukaemia is analysed in the current review. These fluctuations may occur within a specific patient (in different organs) or across patients (individual cases of hypoglycaemia and hyperglycaemia). They can be experienced as stress stimuli by the cancerous population, leading to an alteration of cellular growth kinetics, metabolism and further resistance to chemotherapy. Therefore, it is of high importance to elucidate key mechanisms that affect the evolution of leukaemia under stress. Potential stress response mechanisms are discussed in this review. Moreover, appropriate cell biomarker candidates related to the environmental stress response and/or further resistance to chemotherapy are proposed. Quantification of these biomarkers can enable the combination of macroscopic kinetics with microscopic information, which is specific to individual patients and leads to the construction of detailed mathematical models for the optimisation of chemotherapy. Due to their nature, these models will be more accurate and precise (in comparison to available macroscopic/black box models) in the prediction of responses of individual patients to treatment, as they will incorporate microscopic genetic and/or metabolic information which is patient-specific.peer-reviewe

Chemoradiotherapy screening in a novel biomimetic polymer based pancreatic cancer model

Pancreatic Ductal Adenocarcinoma (PDAC) is a deadly and aggressive disease with a very low survival rate. This is partly due to the resistance of the disease to currently available treatment options. Herein, we report for the first time the use of a novel polyurethane scaffold based PDAC model for screening the short and relatively long term (1 and 17 days post-treatment) responses of chemotherapy, radiotherapy and their combination. We show a dose dependent cell viability reduction and apoptosis induction for both chemotherapy and radiotherapy. Furthermore, we observe a change in the impact of the treatment depending on the time-frame, especially for radiation for which the PDAC scaffolds showed resistance after 1 day but responded more 17 days post-treatment. This is the first study to report a viable PDAC culture in a scaffold for more than 2 months and the first to perform long-term (17 days) post-treatment observations in vitro. This is particularly important as a longer time-frame is much closer to animal studies and to patient treatment regimes, highlighting that our scaffold system has great potential to be used as an animal free model for screening of PDAC

Textile-based non-invasive lithium drug monitoring: A proof-of-concept study for wearable sensing

Flexible wearable chemical sensors are emerging tools which target diagnosis and monitoring of medical conditions. One of the potential applications of wearable chemical sensors is therapeutic drug monitoring for drugs that have a narrow therapeutic range such as lithium. We have investigated the possibility of developing a fibre-based device for non-invasive lithium drug monitoring in interstitial fluid. A flexible cotton-based lithium sensor was coupled with a carbon fibre-based reference electrode to obtain a potentiometric device. In vitro reverse iontophoresis experiments were performed to extract Li+ from under porcine skin by applying a current density of 0.4 mA cm-2 via two electrodes. Carbon fibre-based reverse iontophoresis electrodes were fabricated and used instead of a conventional silver wire-based version and comparable results were obtained. The fibre-based Li+ sensor and reference electrodes were capable of determining the Li+ concentration in samples collected via reverse iontophoresis and the results compared well to those obtained by ion chromatography. Additionally, biocompatibility of the used materials have been tested. Promising results were obtained which confirm the possibility of monitoring lithium in interstitial fluid using a wearable sensor

Textile-based non-invasive lithium drug monitoring: A proof-of-concept study for wearable sensing

Flexible wearable chemical sensors are emerging tools which target diagnosis and monitoring of medical conditions. One of the potential applications of wearable chemical sensors is therapeutic drug monitoring for drugs that have a narrow therapeutic range such as lithium. We have investigated the possibility of developing a fibre-based device for non-invasive lithium drug monitoring in interstitial fluid. A flexible cotton-based lithium sensor was coupled with a carbon fibre-based reference electrode to obtain a potentiometric device. In vitro reverse iontophoresis experiments were performed to extract Li + from under porcine skin by applying a current density of 0.4 mA cm −2 via two electrodes. Carbon fibre-based reverse iontophoresis electrodes were fabricated and used instead of a conventional silver wire-based version and comparable results were obtained. The fibre-based Li + sensor and reference electrodes were capable of determining the Li + concentration in samples collected via reverse iontophoresis and the results compared well to those obtained by ion chromatography. Additionally, biocompatibility of the materials used have been tested. Promising results were obtained which confirm the possibility of monitoring lithium in interstitial fluid using a wearable sensor. </p

Heat adaptation of Escherichia coli K12: Effect of acid and glucose

AbstractThe objective of this work is to investigate the effect of the (possible) acid adaptation during growth in a glucose rich environment on the heat resistance of Escherichia coli K12 MG1655. E. coli cells were grown in TSB and/or TSB dextrose free broth until they reached the stationary phase. Afterwards, the stationary phase cells were added in TSB and/or TSB dextrose free broth and inactivation took place at 54oC and 58oC. It was observed that growth in a glucose rich environment leads to an increased heat resistance, most likely due to a certain level of acid and further heat adaptation via cross protection

A Step-by-Step Methodological Guide for Developing Zonal Multicellular Scaffold-Based Pancreatic Cancer Models

The tumor microenvironment (TME), a complex heterogeneous mixture of various cellular, physical, and biochemical components and signals, is a major player in the process of tumor growth and its response to therapeutic methods. In vitro 2D monocellular cancer models are unable to mimic the complex in vivo characteristics of cancer TME involving cellular heterogeneity, presence of extracellular matrix (ECM) proteins, as well as spatial orientation and organization of different cell types forming the TME. In vivo animal-based studies have ethical concerns, are expensive and time-consuming, and involve models of non-human species. In vitro 3D models are capable of tiding over several issues associated with both 2D in vitro and in vivo animal models. We have recently developed a novel zonal multicellular 3D in vitro model for pancreatic cancer involving cancer cells, endothelial cells, and pancreatic stellate cells. Our model (i) can provide long-term culture (up to 4 weeks), (ii) can control the ECM biochemical configuration in a cell specific manner, (iii) shows large amounts of collagen secretion by the stellate cells mimicking desmoplasia, and (iv) expresses cell-specific markers throughout the whole culture period. This chapter describes the experimental methodology to form our hybrid multicellular 3D model for pancreatic ductal adenocarcinoma, including the immunofluorescence staining on the cell culture

A novel versatile animal-free 3D tool for rapid low-cost assessment of immunodiagnostic microneedles

Microneedle devices offer minimally invasive and rapid biomarker extraction from the skin. However, the lack of effective assessment tools for such microneedle devices can delay their development into useful clinical applications. Traditionally, the microneedle performance is evaluated i) in vivo, using animal models, ii) ex vivo, on excised human or animal skin or iii) in vitro, using homogenised solutions with the target antigen to model the interstitial fluid. In vivo and ex vivo models are considered the gold-standard approach for the evaluation of microneedle devices because of their structural composition, however they do exhibit limitations. More specifically, they have limited availability and they present batch-to-batch variations depending on the skin origin. Furthermore, their use rises ethical concerns regarding compliance with the globally accepted 3Rs principle of reducing the use of animals for research purposes. At the same time, in vitro models fail to accurately mimic the structure and the mechanical integrity of the skin tissue that surrounds the interstitial fluid. In this study, we introduce for the first time an animal-free, mechanically robust, 3D scaffold that has great potential as an accurate in vitro evaluation tool for immunodiagnostic microneedle devices. More specifically, we demonstrate, for the first time, successful extraction and detection of a melanoma biomarker (S100B) using immunodiagnostic microneedles in the 3D culture system. Melanoma cells (A375) were cultured and expanded for 35 days in the highly porous polymeric scaffold followed by in situ capture of S100B with the microneedle device. Scanning electron microscopy showed a close resemblance between the 3D scaffold and human skin in terms of internal structure and porosity. The microneedle device detected S100B in the scaffold (with a detection pattern similar to the positive controls), while the biomarker was not detected in the surrounding liquid supernatants. Our findings demonstrate the great potential of this animal-free 3D tool for rapid and low-cost evaluation of microneedle devices