New Microfluidic System for Electrochemical Impedance Spectroscopy Assessment of Cell Culture Performance: Design and Development of New Electrode Material

Electrochemical impedance spectroscopy (EIS) is widely accepted as an effective and non-destructive method to assess cell health during cell-culture. However, there is a lack of compact devices compatible with microfluidic integration and microscopy that could provide the real-time and non-invasive monitoring of cell-cultures using EIS. In this paper, we reported the design and characterization of a modular EIS testing system based on a patented technology. This device was fabricated using easily processable methodologies including screen-printing of the impedance electrodes and molding or micromachining of the cell culture chamber with an easy assembly procedure. Accordingly, to obtain processable, biocompatible and sterilizable electrode materials that lower the impact of interfacial impedance on TEER (Transepithelial electrical resistance) measurements, and to enable concomitant microscopy observations, we optimized the formulation of the electrode inks and the design of the EIS electrodes, respectively. First, electrode materials were based on carbon biocompatible inks enriched with IrOx particles to obtain low interfacial impedance electrodes approaching the performances of classical non-biocompatible Ag/AgCl second-species electrodes. Secondly, we proposed three original electrode designs, which were compared to classical disk electrodes that were optically compatible with microscopy. We assessed the impact of the electrode design on the response of the impedance sensor using COMSOL Multiphysics. Finally, the performance of the impedance spectroscopy devices was assessed in vitro using human airway epithelial cell cultures.

Food-Related Quality of Life in Cancer Patients: Development and Validation of a Questionnaire

Objectives

Monitoring psychosocial, emotional, and hedonic aspects of food behavior is important to understand cancer patients’ distress and help to reduce risks of malnutrition. However, to date, there is no specific tool to measure the impact of diet, eating behavior, and chemotherapy side effects on patients’ food-related quality of life during cancer and its treatments. The objective was to develop and validate a questionnaire that aims to assess the food-related quality of life in cancer patients undergoing chemotherapy.

Methods

Relevant items from the existing food-related quality of life assessment tools were selected to compose the present 46-item questionnaire. The validation of the questionnaire was conducted in 276 healthy volunteers and 173 cancer patients. Exploratory Factor Analysis

(EFA) was performed in both groups, construct and discriminant validity, and test-retest reliability were calculated.

Results

The questionnaire was perceived as clear and required less than14 minutes for completion (93% complete responses) in a pre-test (n = 156). The EFA allowed the inclusion of 9 dimensions in the food-related quality of life questionnaire. Common patterns between patients and healthy volunteers (factor loadings ≥ 0.4 in both groups) were used to calculate scores by dimension. Scores in the dimensions of adapting diet and sensorial discomfort (taste/odor) were higher in cancer patients, whilst scores in the dimension of discomfort in satiety were higher in healthy volunteers. Among patients with cancer, the total scores in sensorial discomfort, digestive discomfort, and discomfort in satiety were higher under chemotherapy than no treatment. Reproducibility after one week was in increasing order; digestive discomfort 0.6, adapting diet 0.61, products’ quality 0.67, cooking 0.75, healthy diet 0.76, eating and pleasure 0.80, discomfort in satiety 0.82, and sensorial discomfort 0.85.

Conclusions

This 46-item questionnaire can discriminate cancer patients versus healthy volunteers, and patients receiving vs those not receiving chemotherapy. A good to very good reproducibility was found for the most important factors of food-related quality of life of patients with cancer, i.e, eating and pleasure, sensorial discomfort, and discomfort in satiety.

Funding Sources

This study is funded by La Région Auvergne Rhône-Aples and La Métropôle de Lyon.

Development of a multiparametric (bio)sensing platform for continuous monitoring of stress metabolites

There is a growing need for real-time monitoring of metabolic products that could reflect cell damages over extended periods. In this paper, we report the design and development of an original multiparametric (bio)sensing platform that is tailored for the real-time monitoring of cell metabolites derived from cell cultures. Most attractive features of our developed electrochemical (bio)sensing platform are its easy manufacturing process, that enables seamless scale-up, modular and versatile approach, and low cost. In addition, the developed platform allows a multiparametric analysis instead of single-analyte analysis. Here we provide an overview of the sensors-based analysis of four main factors that can indicate a possible cell deterioration problem during cell-culture: pH, hydrogen peroxide, nitric oxide/nitrite and lactate. Herein, we are proposing a sensors platform based on thick-film coupled to microfluidic technology that can be integrated into any microfluidic system using Luer-lock connectors. This platform allows obtaining an accurate analysis of the secreting stress metabolites during cell/tissues culture.

Reference method for off-line analysis of nitrogen oxides in cell culture media by an ozone-based chemiluminescence detector

Nitric oxide (NO) and its by-products are important biological signals in human physiology and pathology particularly in the vascular and immune systems. Thus, in situ determination of the NO-related molecule (NO_x) levels using embedded sensors is of high importance particularly in the context of cellular biocompatibility testing. However, NO_x analytical reference method dedicated to the evaluation of biomaterial biocompatibility testing is lacking. Herein, we demonstrate a PAPA-NONOate-based reference method for the calibration of NO_x sensors. After, the validation of this reference method and its potentialities were demonstrated for the detection of the oxidative stress-related NO secretion of vascular endothelial cells in a 3D tissue issued from 3D printing. Such NO_x detection method can be an integral part of cell response to biomaterials. Graphical abstract.

Nanostructured lipid carriers accumulate in atherosclerotic plaques of ApoE-/- mice

Nanostructured lipid carriers (NLC) might represent an interesting approach for the identification and targeting of rupture-prone atherosclerotic plaques. In this study, we evaluated the biodistribution, targeting ability and safety of ⁶⁴Cu-fonctionalized NLC in atherosclerotic mice. ⁶⁴Cu-chelating-NLC (51.8±3.1 nm diameter) with low dispersity index (0.066±0.016) were produced by high pressure homogenization at tens-of-grams scale. 24 h after injection of ⁶⁴Cu-chelated particles in ApoE^-/- mice, focal regions of the aorta showed accumulation of particles on autoradiography that colocalized with Oil Red O lipid mapping. Signal intensity was significantly greater in aortas isolated from ApoE^-/- mice compared to wild type (WT) control (8.95 [7.58, 10.16]×10⁸ vs 4.59 [3.11, 5.03]×10⁸ QL/mm², P < 0.05). Moreover, NLC seemed safe in relevant biocompatibility studies. NLC could constitute an interesting platform with high clinical translation potential for targeted delivery and imaging purposes in atherosclerosis.

BIOTEX--biosensing textiles for personalised healthcare management

Textile-based sensors offer an unobtrusive method of continually monitoring physiological parameters during daily activities. Chemical analysis of body fluids, noninvasively, is a novel and exciting area of personalized wearable healthcare systems. BIOTEX was an EU-funded project that aimed to develop textile sensors to measure physiological parameters and the chemical composition of body fluids, with a particular interest in sweat. A wearable sensing system has been developed that integrates a textile-based fluid handling system for sample collection and transport with a number of sensors including sodium, conductivity, and pH sensors. Sensors for sweat rate, ECG, respiration, and blood oxygenation were also developed. For the first time, it has been possible to monitor a number of physiological parameters together with sweat composition in real time. This has been carried out via a network of wearable sensors distributed around the body of a subject user. This has huge implications for the field of sports and human performance and opens a whole new field of research in the clinical setting.