Real-Time Cell Temperature Fluctuation Monitoring System Using Precision Pt Sensors Coated with Low Thermal Capacity, Low Thermal Resistance, and Self-Assembled Multilayer Films.

Real-time monitoring of cell temperature fluctuation can help researchers better understand physiological phenomena and the effects of drug treatment on cells, which is a novel and important tool for cellular informatics. The platinum (Pt) temperature sensor is widely used in temperature measurement with the advantages of strong stability, great accuracy, and high sensitivity. However, the commercially available Pt sensors have large thermal resistance and heat capacity which are difficult to be applied for cell temperature measurement because only a very small amount of heat flux is generated by live cells. In this study, we designed a system using precision Pt thin-film temperature sensors with low heat capacity and thermal resistance. The Pt thin-film sensors are covered by a silicon nitride insulation layer grafted with a self-assembled multilayer silane film for promoting cell adhesion. The temperature coefficient of resistance of the Pt temperature sensor was about 2100 ppm/°C. The four-wire lead design next to the sensor detection area ensured maximum accuracy, resulting in a system noise below 0.01 °C over a long time. HEK-293T and HeLa cells were cultured on the sensor surface, respectively. The temperature fluctuation of 293T cells was monitored in a cell culture medium, showing a temperature increase of about 0.05-0.12 °C. The temperature fluctuation of HeLa cells treated with cisplatin was also measured and recorded, indicating a temperature decrease of 0.01 °C first and then a gradual temperature increase of 0.04 °C. The Pt sensor system we developed demonstrated high sensitivity and long stability for cell temperature fluctuation monitoring, which can be widely used in cell activity and cellular informatics studies.

Combined Cellular Thermometry Reveals That Salmonella typhimurium Warms Macrophages by Inducing a Pyroptosis-like Phenotype.

The attenuated Salmonella typhimurium VNP20009, enriched in tumors, is known to have antitumor effects and recruit macrophages. Little is known, however, about whether VNP will lead to specific changes in macrophages, e.g., cell temperature. Here, using a real-time wireless multicell thermometry system, we reported for the first time that VNP20009 increases the macrophage temperature by 0.2 °C. Nigericin, recognized as an inducer of pyroptosis, was found to induce macrophage warming. Moreover, the ΔsipD-VNP20009 strain failed to induce macrophage pyroptosis and simultaneously failed to warm macrophages, and the Gsdmd-/- macrophages that were unable to achieve pyroptosis were no longer warmed following VNP20009 induction. These results suggested that the occurrence of macrophage pyroptosis is the key to VNP20009-mediated cell warming. With the aid of a single-cell thermometry system, it was further confirmed that cell warming occurred in pyroptosis-like macrophages. Cellular warming was not detected after the induction of pyroptosis in macrophages with loss of mitochondrial biological function, suggesting a critical role of mitochondria in warming. Moreover, we found that VNP20009 caused local tumor temperature increases. The local tumor warming induced by VNP20009 was significantly reduced after macrophage clearance. Notably, this temperature increase contributed to M1-type polarization. These findings expanded our knowledge of the cellular biological changes induced by the strain on macrophages, as well as the biochemical phenomena accompanying pyroptosis, and provide a reference for the study of biochemical signals transduced to biothermal signals with a combined cell-level temperature detector.

Cell Temperature Measurement for Biometabolism Monitoring.

Temperature is an important factor in the process of life, as thermal energy transfer participates in all biological events in organisms. Due to technical limitations, there is still a lot more information to be explored regarding the correlation between life activities and temperature changes. In recent years, the emergence of a variety of new temperature measurement methods has facilitated further research in this field. Here, we introduce the latest advances in temperature sensors for biological detection and their related applications in metabolic research. Various technologies are discussed in terms of their advantages and shortcomings, and future prospects are presented.

Exploring the 'cold/hot' properties of traditional Chinese medicine by cell temperature measurement.

Context: It is common sense that chewing a mint leaf can cause a cooling feeling, while chewing ginger root will produce a burning feeling. In Traditional Chinese Medicine (TCM), this phenomenon is referred to as 'cold/hot' properties of herbs. Herein, it is reported that TCM with different "cold/hot" properties have different effects on the variation of cells.Objective: To explore the intrinsic 'cold/hot' properties of TCM from the perspective of cellular and molecular biology.Materials and methods: A375 cells were selected using Cancer Cell Line Encyclopaedia (CCLE) analysis and western blots. Hypaconitine and baicalin were selected by structural similarity analysis from 56 and 140 compounds, respectively. A wireless thermometry system was used to measure cellular temperature change induced by different compounds. Alteration of intracellular calcium influx was investigated by means of calcium imaging.Results: The IC50 values of GSK1016790A, HC067047, hypaconitine, and baicalin for A375 cells are 8.363 nM, 816.4 µM, 286.4 µM and 29.84 µM, respectively. And, 8 µM hypaconitine induced obvious calcium influx while 8 µM baicalin inhibited calcium influx induced by TRPV4 activation. Cellular temperature elevated significantly when treated with GSK1016790A or hypaconitine, while the results were reversed when cells were treated with HC067047 or baicalin.Discussion and conclusions: The changes in cellular temperature are speculated to be caused by the alteration of intracellular calcium influx mediated by TRPV4. In addition, the 'cold/hot' properties of compounds in TCM can be classified by using cellular temperature detection.

Magnetically targeted photothemal cancer therapy in vivo with bacterial magnetic nanoparticles.

The biomineralized bacterial magnetic nanoparticles (BMPs) have been widely studied for biomedical applications with their magnetic properties and a layer of biomembrane. Herein, BMPs were firstly used for magnetically targeted photothermal cancer therapy in vivo. A self-build C-shaped bipolar permanent magnet was used for magnetic targeting though the generation of a high gradient magnetic field within a small target area. For in vitro simulated experiment, BMPs had a high retention rate in magnetically targeted region with different flow rates. In H22 tumor bearing mice, the magnetic targeting induced a 40% increase of BMPs retention in tumor tissues. In vivo photothermal therapy with 808 nm laser irradiation could induce a complete tumor elimination with magnetic targeting. These results indicated that the systematically administrated BMPs with magnetic targeting would be promising for photothermal cancer therapy.

[Analysis of chemical markers in sulfur-fumigated Anemarrhenae Rhizoma].

Sulfur-containing Anemarrhenae Rhizoma decoction pieces were prepared by using sulfur-fumigating procedure. The difference components before and after sulfur fumigation in Anemarrhenae Rhizoma were analyzed and on-line identified by UPLC-Q-TOF-MSE combined with UNIFI informatics platform, principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) respectively. As a result, 16 major differences components were identified, and among them, 9 components were mainly from sulfur-fumigated samples. The main chemical markers in sulfur-fumigated Anemarrhenae Rhizoma were identified as the sulfite derivatives newly produced after sulfur-fumigating. Meanwhile, UPLC-Q-TOF-MSE was used to find the main chemical marker anemarrhena saponin BⅡ sulfite (m/z 983). By using this method, a rapid screening method for sulfur-fumigated Anemarrhenae Rhizoma was established. This was a convenient and accurate detection method for sulfur dioxide residue, and it can be used as an effective assistant method to control the quality of Anemarrhenae Rhizoma. At the same time, it was the first time to identify sulfited derivatives of steroidal saponins, and screen the sulfur-fumigated Anemarrhenae Rhizoma.

Rapid Characterization of Constituents in Tribulus terrestris from Different Habitats by UHPLC/Q-TOF MS.

A strategy for rapid identification of the chemical constituents from crude extracts of Tribulus terrestris was proposed using an informatics platform for the UHPLC/Q-TOF MSE data analyses. This strategy mainly utilizes neutral losses, characteristic fragments, and in-house library to rapidly identify the structure of the compounds. With this strategy, rapid characterization of the chemical components of T. terrestris from Beijing, China was successfully achieved. A total of 82 steroidal saponins and nine flavonoids were identified or tentatively identified from T. terrestris. Among them, 15 new components were deduced based on retention times and characteristic MS fragmentation patterns. Furthermore, the chemical components of T. terrestris, including the other two samples from Xinjiang Uygur Autonomous region, China, and Rome, Italy, were also identified with this strategy. Altogether, 141 chemical components were identified from these three samples, of which 39 components were identified or tentatively identified as new compounds, including 35 groups of isomers. It demonstrated that this strategy provided an efficient protocol for the rapid identification of chemical constituents in complex samples such as traditional Chinese medicines (TCMs) by UHPLC/Q-TOF MSE with informatics platform. Graphical Abstract ᅟ.

An efficient approach to identify different chemical markers between fibrous root and rhizome of Anemarrhena asphodeloides by ultra high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry with multivariate statistical analysis.

An ultra high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry approach coupled with multivariate statistical analysis was established and applied to rapidly distinguish the chemical differences between fibrous root and rhizome of Anemarrhena asphodeloides. The datasets of tR-m/z pairs, ion intensity and sample code were processed by principal component analysis and orthogonal partial least squares discriminant analysis. Chemical markers could be identified based on their exact mass data, fragmentation characteristics, and retention times. And the new compounds among chemical markers could be isolated rapidly guided by the ultra high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry and their definitive structures would be further elucidated by NMR spectra. Using this approach, twenty-four markers were identified on line including nine new saponins and five new steroidal saponins of them were obtained in pure form. The study validated this proposed approach as a suitable method for identification of the chemical differences between various medicinal parts in order to expand medicinal parts and increase the utilization rate of resources.

Furostanol and Spirostanol Saponins from Tribulus terrestris.

Twelve new steroidal saponins, including eleven furostanol saponins, terrestrinin J-T (1-11), and one spirostanol saponin, terrestrinin U (12), together with seven known steroidal saponins 13-19 were isolated from T. terrestris. The structures of the new compounds were established on the basis of spectroscopic data, including 1D and 2D NMR and HRESIMS, and comparisons with published data.

New steroidal glycosides from the rhizome of Anemarrhena asphodeloides.

Two new steroidal saponins, timosaponin X (1) and timosaponin Y (2), and one new pregnane glycoside, timopregnane B (3), were isolated from the rhizomes of Anemarrhena asphodeloides, as well as three known compounds 25S-timosaponin BII (4), protodesgalactotigonin (5), and timosaponin BII-a (6) isolated from this plant for the first time. By the detailed analysis of 1D, 2D NMR, MS spectra, and chemical evidences, the structures of new compounds were elucidated as 26-O-ß-d-glucopyranosyl-(25S)-5ß-22-methoxy-furost-3ß,26-diol 3-O-ß-d-glucopyranosyl-(1 → 2)-α-l-arabinopyranoside (1), 5ß-pseudo-spirost-3ß,15α,23α-triol 3-O-ß-d-glucopyranosyl-(1 → 2)-ß-d-galactopyranoside (2), (5ß,17α)-Δ((16)(17))-20-one-pregn-2ß,3ß-diol 3-O-ß-d-glucopyranosyl-(1 → 2)-ß-d-galactopyranoside (3).