Development of a carboxyl-terminated indium tin oxide electrode for improving cell adhesion and facilitating low noise, real-time impedance measurements.

The working electrode's surface property is crucial to cell adhesion and signal collection in electric cell-substrate impedance sensing (ECIS). To date, the indium tin oxide (ITO)-based working electrode is of interest in ECIS study due to its high transparency and biocompatibility. Of great concern is the impedance signal loss, distortion, and data interpretation conflict profoundly created by the movement of multiple cells during ECIS study. Here, a carboxyl-terminated ITO substrate was prepared by stepwise surface amino silanization, with N-hydroxy succinimide (NHS) and 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) treatment, respectively. We investigated the stepwise changes in the property of the treated ITO, cell-substrate adhesion, collective cell mobility, and time course of change in absolute impedance from multiple Chinese hamster ovary (CHO) cells [(Δt-Δ|Z|)CELLS]. The carboxyl-terminated ITO substrate with a surface roughness of 6.37 nm shows enhanced conductivity, 75% visible light transparency, improved cell adherence, reduced collective cell migration speed by approximately twofold, and diminished signal distortion in the [(Δt-Δ|Z|)CELLS]. Thus, our study provides an ITO surface-treatment strategy to reduce multiple cell movement effects and to obtain essential cell information from the ECIS study of multiple cells through undistorted (Δt-Δ|Z|)CELLS.

Stable and Salt-Resistant Janus Evaporator Based on Cellulose Composite Aerogels from Waste Cotton Fabric.

Solar steam generation has been considered a promising approach for using renewable solar energy to produce clean water from seawater and wastewater. It shows great potential for alleviating water shortages. However, salt accumulation and system longevity are challenges which impede the widespread use of evaporators. This paper reports a stable Janus evaporator with thickness controllable hydrophilic and hydrophobic layers based on cellulose composite aerogels, which were extracted from waste cotton fabric by a two-step freeze-drying process. The obtained glutaraldehyde cross-linked carbon nanotubes/cellulose Janus aerogel exhibited an attractive solar steam generation rate of 1.81 kg·m-2·h-1 and a light-to-vapor efficiency of up to 92.5% in 1 sun illumination. Moreover, the Janus solar steam generator could pledge stable and sustainable solar-driven water evaporation performance within a 10 h test, showing a high salt-resistant property in simulated seawater. In addition, the developed solar evaporator also had a good purification effect on dye wastewater. These findings suggest its potential ability for seawater desalination and wastewater purification.

Single cell analysis of mechanical properties and EMT-related gene expression profiles in cancer fingers.

Collective cell migration is associated with cancer metastasis. Cancer fingers are formed when groups of migrating cancer cells follow the leader cells in the front. Epithelial to mesenchymal transition (EMT) is a critical process of cancer metastasis. However, the role of EMT in cancer finger formation remains unclear. In this work, we investigated the EMT-associated mechanical properties and gene expression at single-cell levels in non-small lung cancer fingers. We found that leader cells were more elastic and less sticky than follower cells. Spatial EMT-related gene expression profiling in cancer fingers revealed cellular heterogeneity. Particularly, SNAIL and VIM were found to be two key genes that positively correlated with leader cell phenotypes and controlled cancer finger formation. Silencing either SNAIL or VIM, decreased cancer cell elasticity, cancer finger formation and migration, and increased adhesiveness. These findings indicated that SNAIL and VIM are two driver genes for cancer finger formation.

Sustainable Cellulose Aerogel from Waste Cotton Fabric for High-Performance Solar Steam Generation.

The textile industry has been considered as one of the polluting industries, producing a large amount of textile waste and CO2 emissions each year. Recycling of waste fabric has attracted more research interest in recent years. Herein, renewable polydopamine (PDA)-functionalized cellulose aerogels (CAs) have been designed by a feasible and green way for clean water generation. With the polymerization of PDA on the surface, which possesses excellent photothermal conversion performance and water purification ability, the resulting CA could achieve a high light absorption of 96.5% with the evaporation rate of 2.74 kg m-2 h-1 under 1 sun. Meanwhile, the solar steam generator with the increasing height can absorb energy from adjacent ambient air to strengthen the vapor generation. The features of renewable CAs can achieve efficient water evaporation, which combined with their low material cost and recycling, offer promise in reducing not only energy consumption but also the environmental footprint of cotton textiles.

Investigation on the Direct and Bystander Effects in HeLa Cells Exposed to Very Low α-Radiation Using Electrical Impedance Measurement.

The impact of radiation-induced bystander effect (RIBE) is still not well understood in radiotherapy. RIBEs are biological effects expressed by nonirradiated cells near or far from the irradiated cells. Most radiological studies on cancer cells have been based on biochemical characterization. However, biophysical investigation with label-free techniques to analyze and compare the direct irradiation effect and RIBE has lagged. In this work, we employed an electrical cell-indium tin oxide (ITO) substrate impedance system (ECIIS) as a bioimpedance sensor to evaluate the HeLa cells' response. The bioimpedance of untreated/nonirradiated HeLa (N-HeLa) cells, α-particle (Am-241)-irradiated HeLa (I-HeLa) cells, and bystander HeLa (B-HeLa) cells exposed to media from I-HeLa cells was monitored with a sampling interval of 8 s over a period of 24 h. Also, we imaged the cells at times where impedance changes were observed. Different radiation doses (0.5 cGy, 1.2 cGy, and 1.7 cGy) were used to investigate I-HeLa and B-HeLa cells' radiation-dose-dependence. By analyzing the changes in absolute impedance and cell size/number with time, compared to N-HeLa cells, B-HeLa cells mimicked the I-HeLa cells' damage and modification of proliferation rate. Contrary to the irradiated cells, the bystander cells' damage rate and proliferation rate enhancements have an inverse radiation-dose-response. Also, we report multiple RIBEs in HeLa cells in a single measurement and provide crucial insights into the RIBE mechanism without any labeling procedure. Unambiguously, our results have shown that the time-dependent control of RIBE is important during α-radiation-based radiotherapy of HeLa cells.

CHO cell dysfunction due to radiation-induced bystander signals observed by real-time electrical impedance measurement.

Radiation-induced bystander effects (RIBE) have raised many concerns about radiation safety and protection. In RIBE, unirradiated cells receive signals from irradiated cells and exhibit irradiation effects. Until now, most RIBE studies have been based on morphological and biochemical characterization. However, research on the impact of RIBE on biophysical properties of cells has been lagging. Non-invasive indium tin oxide (ITO)-based impedance systems have been used as bioimpedance sensors for monitoring cell behaviors. This powerful technique has not been applied to RIBE research. In this work, we employed an electrical cell-ITO substrate impedance system (ECIIS) to study the RIBE on Chinese hamster ovary (CHO) cells. The bioimpedance of bystander CHO cells (BCHO), alpha(α)-particle (Am-241) irradiated CHO (ICHO), and untreated/unirradiated CHO (UCHO) cells were monitored with a sampling interval of 8 s over a period of 24 h. Media from ICHO cells exposed to different radiation doses (0.3 nGy, 0.5 nGy, and 0.7 nGy) were used to investigate the radiation dose dependence of BCHO cells' impedance. In parallel, we imaged the cells at times where impedance changes were observed. By analyzing the changes in absolute impedance and cell size/cell number with time, we observed that BCHO cells mimicked ICHO cells in terms of modification in cell morphology and proliferation rate. Furthermore, these effects appeared to be time-dependent and inversely proportional to the radiation dose. Hence, this approach allows a label-free study of cellular responses to RIBE with high sensitivity and temporal resolution and can provide crucial insights into the RIBE mechanism.

Inhibition of Glioma Cells' Proliferation by Doxorubicin-Loaded Exosomes via Microfluidics.

BACKGROUND: Malignant glioma is a fatal brain cancer. Accumulated evidence has demonstrated that exosomes can cross the blood-brain barrier (BBB), suggesting their potential use as drug delivery vehicles to glioma. Therefore, various loading methods of anticancer agents into exosomes have been developed. However, the loading efficiency of anticancer drugs, such as doxorubicin (DOX) and paclitaxel (PTX), into exosomes is relatively low, thus challenging to improve the drug delivery efficiency to glioma cells (GMs) via exosomes. METHODS: To improve the loading efficiency of doxorubicin into exosomes, a microfluidic device (Exo-Load) was developed. Next, to increase the exosomal delivery of doxorubicin to GMs, autologous exosomes were used for its loading via Exo-Load. Briefly, exosomes from SF7761 stem cells-like- and U251-GMs were isolated and characterized by nano-tracking analysis (NTA), transmission electron microscopy (TEM), and immunogold EM. Finally, doxorubicin was successfully loaded into exosomes with saponin by Exo-Load, and the uptake and functionality of doxorubicin-loaded exosomes for parent GMs were evaluated. RESULTS: The loading efficiency of DOX into SF7761 stem cells-like- and U251-GMs-derived-exosomes were 19.7% and 7.86% via Exo-Load at the injection flow rate of 50 µL/min, respectively. Interestingly, the loading efficiency of DOX into U251 GMs-derived exosomes was significantly improved to 31.98% by a sigmoid type of Exo-Load at the injection flow rate of 12.5 µL/min. Importantly, DOX-loaded GMs-derived exosomes via Exo-Load inhibited parent GMs' proliferation more than heterologous GMs, supporting exosomes' homing effect. CONCLUSION: This study revealed that DOX and PTX could be loaded in exosomes via Exo-Load, demonstrating that Exo-Load could be a potential drug-loading device into exosomes with further optimization. This study also demonstrated that the delivery of DOX to SF7761 GMs via their daughter exosomes was much more efficient rather than U251 GMs-derived exosomes, supporting that the use of autologous exosomes could be better for glioma drug targeting.

Recent advances in microfluidic technology for manipulation and analysis of biological cells (2007-2017).

The pivotal role of microfluidic technology in life science and biomedical research is now widely recognized. Indeed, microfluidics as a research tool is unparalleled in terms of its biocompatibility, robustness, efficient reagent consumption, and controlled fluidic, surface, and structure environments. The controlled environments are essential in assessing the complex behavior of cells in response to microenvironmental cues. The strengths of microfluidics also reside in its amenability to integration with other analytical platforms and its capacity for miniaturization, parallelization and automation of biochemical assays. Following previous review on the applications of microfluidic devices for cell-based assays in 2006, we have monitored the progress in the field and summarized the advances in microfluidic technology from 2007 to 2017, with a focus on microfluidics development for applications in cell manipulation, cell capture and detection, and cell treatment and analysis. Moreover, we highlighted novel commercial microfluidic products for biomedical and clinical purposes that were introduced in the review period. Thus, this review provides a comprehensive source for recent developments in microfluidics and presents a snapshot of its remarkable contribution towards basic biomedical research and clinical science. We recognize that although enormous amounts of evidence have reinforced the promise of microfluidic technology across diverse applications, much remains to be done to realize its full potential in mainstream biomedical science and clinical practice.

Countrywide radiation dose in different locations, dwellings and free spaces of Bangladesh.

The research work was aimed to determine the fatal cancer risk due to the radiation exposure on population of Bangladesh. The total risk is somewhat higher. However, the average total fatal probability coefficient was found to be 101 cases per million people, the range of which was from 78 to 144 per million people. The lowest risk was found for the people of Srimangal (Maulavibazar) and Sandweep, while the risk was highest for the people of Nachole (Chapai Nawabgonj) and Badalgachhi (Naogaon), the two locations are in the Borendra region. The risk factors were found to be around average level for the people of Dhaka, Chittagong and Rajshahi. Since a very significant portion of people of Bangladesh live in these areas, the calculated average risk factor become more meaningful. Moreover, as both the average effective dose equivalents and the population density in Bangladesh are higher than those of the countries compared, the people of Bangladesh are in more risk than those countries.

Measurement of physiochemical parameters and determination of the level of radiological threat to the population associated with the Karnaphuli River sediment containing municipal and industrial wastes of Chittagong city in Bangladesh.

The research work has been aimed to assess the radiological and chemical threat caused due to urban and industrial wastage drainage to the inhabitants of the Chittagong city in Bangladesh. For finding the chemical effects along with the measurement of radiological threat, the physiochemical characteristics (temperature, pH value and oxidation-reduction potential) of the sediment samples have been analysed. The activity concentrations of naturally occurring radionuclides (238)U, (232)Th, (226)Ra and (40)K in the investigated samples have been found to be higher than those of the world average values. The artificial radionuclide (137)Cs in the samples studied has not been detected. The mean value of the radium equivalent activity and outdoor exposure rate in the study region have been found to be 240.94 ± 23.12 Bq kg(-1) and 115.82 ± 10.81 nGy h(-1), respectively. The radiation doses have been measured directly by employing beta-gamma survey meter (model: LUDLUM 44-9) from where the samples have been collected. The average values of the radiological parameters have been calculated from the activity concentrations of the radionuclides mentioned in the sediment samples found to be higher than those of the corresponding world average values.