Changes In Cell Volume Research Articles

Biophysical and Morphological Cell Features Retrieved by Digital Holographic Microscopy Correlate with Drug-Induced Changes in Cell Migration Behavior.

Quantitative analysis of cancer cell migration is critical for developing effective therapies to curb cancer metastasis. However, traditional methods are time-consuming and labor-intensive and lack quantitative capabilities. Cell volume change, a key physiological indicator of cell migration, is directly linked to phase change. In this work, we have developed a model that connects phase features from digital holographic microscopy (DHM) with cell healrate values from the wound healing assay. This approach aims to provide a rapid and quantitative evaluation of the breast cancer cell migration capability. Using DHM, six phase features of 231 cells treated with varying drug concentrations were extracted. It was observed that the rate of change of these phase features, termed characteristic parameters, showed a high linear correlation with cell healrate values from wound healing assays. Based on these linear correlations, a composite coefficient was derived by linearly combining the characteristic parameters of the six phase features. This composite coefficient was then linearly correlated with the cell healrate values to create a correlation model. This model establishes a strong connection between DHM-extracted morphological/biophysical features and cell migration metrics from a complementary assay. It provides a new, rapid, and quantitative method for assessing cancer cell migration in vitro and delivering valuable insights for cancer research.

Mechanobiology of 3D cell confinement and extracellular crowding

AbstractCells and tissues are often under some level of confinement, imposed by the microenvironment and neighboring cells, meaning that there are limitations to cell size, volume changes, and fluid exchanges. 3D cell culture, increasingly used for both single cells and organoids, inherently impose levels of confinement absent in 2D systems. It is thus key to understand how different levels of confinement influences cell survival, cell function, and cell fate. It is well known that the mechanical properties of the microenvironment, such as stiffness and stress relaxation, are important in activating mechanosensitive pathways, and these are responsive to confinement conditions. In this review, we look at how low, intermediate, and high levels of confinement modulate the activation of known mechanobiology pathways, in single cells, organoids, and tumor spheroids, with a specific focus on 3D confinement in microwells, elastic, or viscoelastic scaffolds. In addition, a confining microenvironment can drastically limit cellular communication in both healthy and diseased tissues, due to extracellular crowding. We discuss potential implications of extracellular crowding on molecular transport, extracellular matrix deposition, and fluid transport. Understanding how cells sense and respond to various levels of confinement should inform the design of 3D engineered matrices that recapitulate the physical properties of tissues.

Isosmotic Striction of Rat Aorta Smooth Muscle Cells During Activation of Purinergic Receptors: Role of Chlorine Transport

We studied the effect of the purinergic signaling system and Cl-transporters on vascular smooth muscle cells (SMC) isosmotic striction that occurs when osmotic pressure is normalized after prolonged incubation in a hypoosmotic medium. The study was performed with the method of myography on endothelium-denuded ring segments of the male Wistar rats aorta. Isosmotic striction was induced by placing the vascular segments in normosmotic Krebs solution containing 120 mM NaCl after a 40-minute incubation in a hyposmotic Krebs solution containing 40 mM NaCl. Purinergic receptors were activated by adenosine 5'-triphosphate (ATP, 500 μM) as nonselective P2X and P2Y receptor agonist, and uridine 5'-triphosphate (UTP, 500 μM) as selective P2Y receptor agonist. ATP and UTP eliminated the transient nature of the aorta SMC isosmotic striction without affecting its amplitude. Pretreatment of vascular segments with ATP and UTP during incubation in a hyposmotic solution completely suppressed the development of isosmotic striction in the presence of ATP or UTP, but did not affect isosmotic striction without activators of purinergic receptors. The inhibitor of Na+, K+, 2Cl--cotransport (NKCC) bumetanide (100 μM) abolished isosmotic striction in the presence of ATP, but not UTP, but restored its transient character. A non-selective blocker of Cl– channels and Cl–, HCO3– exchanger DIDS (100 μM) suppressed the development of isosmotic striction both in the presence of ATP and UTP. The potassium channel blocker tetraethylammonium (10 mM) potentiates the constrictor action of UTP on isosmotic striction. We suppose purinergic receptors eliminate the transient isosmotic striction by activating Cl– currents through activation of P2Y receptors. The mechanism of interaction between the purinergic signaling system and Cl– transport during changes in cell volume requires further study.

Dynamic Two-Dimensional Covalent Organic Frameworks with Large Solvent-Induced Lattice Expansion.

Dynamic covalent organic frameworks (COFs) can switch reversibly between crystalline phases with different unit cell parameters and porosities upon physisorption of guest molecules. While impressive changes in unit cell volumes have been realized for three-dimensional frameworks, the solvent-induced volume changes of two-dimensional (2D) COFs have remained comparably small. We have now developed a series of 2D COFs where we systematically varied the length of the interconnecting bridge units. The optimized materials achieve solvent-induced expansions of up to 85% relative to the volume of the solvent-free contracted COFs. These structural changes are fully reversible and the frameworks fully retain their high degree of crystalline order. This study introduces a versatile design strategy for dynamic 2D COFs, which could enable future applications of these materials in gas separation and sensing.

Modeling Reversible Volume Change in Automotive Battery Cells with Porous Silicon Oxide-Graphite Composite Anodes

Automotive battery manufacturers are working to improve the individual cell and overall pack design by increasing durability, performance, and range, while reducing cost, and active material volume change is a key aspect that needs to be considered during this design process. Recently, silicon oxide-graphite composite anodes are being explored to increase total anode capacity while maintaining a tolerable amount of cell level reversible volume expansion due to the relatively lower reversible volume change of the silicon oxide compared to pure battery grade or metallurgical grade silicon. To predict the blended anode response and contribution to the overall cell volume change, we integrated the mechanical behavior of the individual active materials with the multi-species, multi-reaction model to predict the state-of-lithiation of the active materials in the cell at a given potential. The resulting simulations illustrate the tradeoff in volume change between the silicon oxide and the graphite during cell operation. This type of modeling approach will allow designers to virtually consider the impact of cell level and pack level design changes on overall system mechanical performance for automotive and grid storage applications, namely that relatively small addition of silicon containing materials can drive a significant increase in the volume change at the cell level, as demonstrated by the 5 wt% addition of silicon oxide accounting for half of the overall volume change in the cell.

Structural modulation of Na4Fe3(PO4)2P2O7 via cation engineering towards high-rate and long-cycling sodium-ion batteries

Mixed iron-based phosphate Na4Fe3(PO4)2P2O7/C (NFPP) has gradually emerged as a promising cathode material for sodium-ion batteries (SIBs) owing to its affordability and convenient preparation. However, poor electrical conductivity and inadequate sodium-ion diffusion limit the exertion of its electrochemical properties. Herein, a structural modulation strategy based on Cd doping is applied to NFPP to address the above limitations. In situ X-ray diffraction analysis reveals that Cd-doped NFPP (NFCPP) undergoes an incomplete solid-solution reaction driven by Fe2+/Fe3+ redox. Cd doping effectively stabilises the crystal structure, resulting in a minimal 1 % change in unit cell volume during cycling. Density of state calculations indicate that Cd doping reduces the band gap, increases the local electron density and significantly improves electron conductivity. Benefitting from the enhanced electrochemical kinetics and intercalation pseudocapacitance, the optimised Na4Fe2.91Cd0.09(PO4)2P2O7/C (NFCPP@3%) exhibits exceptional rate performance (capacity of 62 mAh/g at 20 C) and ultra-long cycling life (82.7 % after 6000 cycles at 20 C). A full SIB prepared using NFCPP@3% and hard carbon, display a 91 % capacity retention rate at a current density of 130 mA g−1 over 200 cycles. This work demonstrates that doping can effectively enhance electrochemical performance and offers insights into future development of SIBs.

Bacterial cell size modulation along the growth curve across nutrient conditions.

Under stable growth conditions, bacteria maintain cell size homeostasis through coordinated elongation and division. However, fluctuations in nutrient availability result in dynamic regulation of the target cell size. Using microscopy imaging and mathematical modelling, we examine how bacterial cell volume changes over the growth curve in response to nutrient conditions. We find that two rod-shaped bacteria, Escherichia coli and Salmonella enterica, exhibit similar cell volume distributions in stationary phase cultures irrespective of growth media. Cell resuspension in rich media results in a transient peak with a five-fold increase in cell volume ≈ 2h after resuspension. This maximum cell volume, which depends on nutrient composition, subsequently decreases to the stationary phase cell size. Continuous nutrient supply sustains the maximum volume. In poor nutrient conditions, cell volume shows minimal changes over the growth curve, but a markedly decreased cell width compared to other conditions. The observed cell volume dynamics translate into non-monotonic dynamics in the ratio between biomass (optical density) and cell number (colony-forming units), highlighting their non-linear relationship. Our findings support a heuristic model comparing modulation of cell division relative to growth across nutrient conditions and providing novel insight into the mechanisms of cell size control under dynamic environmental conditions.

Studies on highly stable Na7Fe3(P2O7)4 as anode materials for lithium-ion batteries and migration behavior of lithium ions

In this paper, Na7Fe3(P2O7)4 target material is firstly evaluated as potential anode material for lithium ion batteries. It is found to have good electro-chemical performance and high stability as anode material for lithium batteries. It shows a capacity of 290 mAh g−1 for 200 cycles and increases to 388 mAh g−1 for 1000 cycles at a current density of 150 mA g−1. The Coulomb efficiency is maintained at about 98 % during the long cycling. The ex-situ experimental results indicate that Na7Fe3(P2O7)4 has high structural stability and the changes of cell volume and cell parameters are <0.62 % during charging and discharging. The results of GITT data show that the diffusion coefficients range from 3.15 × 10−11 cm2 S−1 to 1.12 × 10−12 cm2 S−1.The Li+/Na+ diffusion paths are estimated by the Bond valence-energy landscape (BEL) method and the exact energy barriers and minimal energy paths (MEPs) are determined using the nudged elastic band (NEB) method implemented in density functional theories (DFT). A two dimensional Na+ diffusion network is observed and Na+ diffusion along c-axis is prohibited. For the initial discharge stage, Na+ migrates in the Na+ transportation channel with an energy barrier of 0.48 eV along a-axis and 0.46 eV along b-axis. For the discharge later on, the intercalated Li+ enters the nearby Na+ vacancies and also migrate in the Na+ channel except Li+ at 8f Lid sites, which will stay where it is firstly introduced because of the higher energy barrier of 0.75 eV. The immobility of Lid is one of the important reasons for the irreversible capacity loss after the initial charge/discharge cycle.

Mechanisms of Glioblastoma Replication: Ca2+ Flares and Cl- Currents.

Glioblastoma (GBM) is amongst the deadliest types of cancers, with no resolutive cure currently available. GBM cell proliferation in the patient's brain is a complex phenomenon controlled by multiple mechanisms. The aim of this study was to determine whether the ionic fluxes controlling cell duplication could represent a target for GBM therapy. In this work, we combined multi-channel Ca2+ and Cl- imaging, optical tweezers, electrophysiology, and immunohistochemistry to describe the role of ion fluxes in mediating the cell volume changes that accompany mitosis of U87 GBM cells. We identified three main steps: (i) in round GBM cells undergoing mitosis, during the transition from anaphase to telophase and cytokinesis, large Ca2+ flares occur, reaching values of 0.5 to 1 μmol/L; (ii) these Ca2+ flares activate Ca2+-dependent Cl- channels, allowing the entry of Cl- ions; and (iii) to maintain osmotic balance, GBM cells swell to complete mitosis. This sequence of steps was validated by electrophysiological experiments showing that Cl- channels are activated either directly or indirectly by Ca2+, and by additional live-cell imaging experiments. Cl- channel blockers with different molecular structures, such as niflumic acid and carbenoxolone, blocked GBM replication by arresting GBM cells in a round configuration. These results describe the central role of Ca2+ flares and Cl- fluxes during mitosis and show that inhibition of Ca2+-activated Cl- channels blocks GBM replication, opening the way to new approaches for the clinical treatment of GBM. Implications: Our work identifies ionic fluxes occurring during cell division as targets for devising novel therapies for glioblastoma treatment.

Chemical Substitution Strategies for Tailoring P2- and O3-Type Layered Oxide Cathodes in Sodium-Ion Batteries

Among cathodes for sodium-ion batteries (SIBs), layered transition metal oxides Na x MO2 (M = transition metal) are very promising due to their easy synthesis and high theoretical capacity.1,2 In this class, Ni/Mn/Fe-based layered oxides are attractive due to the high redox potential of Ni2+/ Ni4+ and Jahn Teller inactive centers (Ni2+, Fe3+,and Mn4+).3 However, complex phase transitions, Na+/vacancy ordering and transition-metal (TM) migration degrade their electrochemical performances.4 To address the issues, a widely studied cathode- P2-type Na0.67[Ni0.33Mn0.67]O2 is chosen and Li+ is substituted in the TM-layer to tailor a series of high Na-content cathodes. Among them, Na0.85[Li0.14Ni0.29Mn0.57]O2 cathode with optimal Li-substitution exhibits a reversible capacity of 168 mAh g-1 at 0.1 C rate and good cycling stability (82% retention after 100 cycles).5 In-situ XRD measurement reveals a complete solid-solution formation and X-ray absorption spectroscopy studies confirm the participation of Ni4+/Ni2+ and Mn4+/Mn3+ redox couples during Na+-extraction/insertion. Lastly, a full Na-ion cell with hard carbon is demonstrated with an energy density of 420 Wh kg-1. In subsequent work, a Li and Ti co-substitution strategy is applied to design a high-entropy O3-type NaLixNiyFezMn0.5Ti0.5-aO2 cathode.6 It retains 77% of its initial capacity after 400 cycles at a 2 C rate with a facile O3-P3-OP2-P3-O3 phase transition. The co-substitution strategy uplifts the average voltage of the system, improves the reversibility of the high-voltage OP2 phase, and enhances the Na-ion diffusion rate. A mere 1.32% unit cell volume change and diminishing electrochemical cell resistance over cycling ensure its superior long-term cycling performance. A full cell is fabricated, which holds 62% of its initial capacity even after 1000 cycles at a 0.5 C rate. Therefore, mono- and di-ion substitution strategies hold enormous potential for designing high-performing P2- and O3-type cathode materials for practical SIBs. References T. Hosaka, K. Kubota, A. S. Hameed, and S. Komaba, Chem. Rev., 120, 6358–6466 (2020).J. Y. Hwang, S. T. Myung, and Y. K. Sun, Chem. Soc. Rev., 46, 3529–3614 (2017).F. Zhang, J. Liao, L. Xu, W. Wu, and X. Wu, ACS Appl. Mater. Interfaces, 13, 40695–40704 (2021).Z. Lu and J. R. Dahn, J. Electrochem. Soc., 148, A1225 (2001).A. Ghosh, B. Senthilkumar, S. Ghosh, P. Amonpattaratkit, and P. Senguttuvan, J. Electrochem. Soc., 170, 030538 (2023).A. Ghosh, R. Hegde, and P. Senguttuvan, J. Mater. Chem. A., submitted(2023).

The thermal expansion of Ti-substituted CaAl12O19

CaAl12O19, which can incorporate Ti as both Ti3+ and Ti4+ (charge coupled substitution with Mg2+), is one of the first minerals to condense from a gas of solar composition and is used as a ceramic. It is variously known as hibonite, calcium hexaluminate (CaO.6Al2O3), and CA6. The lattice parameters and unit cell volumes of Ti-substituted hibonite (P63/mmc) with the formulae CaAl11.8Ti3+0.2O19 and CaAl9.8Ti3+0.54Mg0.83Ti4+0.83O19 were determined as a function of temperature from ~ 10 to 275 K by neutron powder diffraction. The thermal expansion is highly anisotropic with the expansion in c a factor of ~ 5 greater than that in a. The change in a is approximately equal for the two compounds whereas the change in c is almost 50% larger for CaAl11.8Ti3+0.2O19. CaAl11.8Ti3+0.2O19 also exhibits negative thermal expansion between 10 and 70 K. The change in unit cell volume with temperature of both compositions is well described by a two term Einstein expression. The large change in c is consistent with substitution of Ti onto the M2 and M4 sites of the R-block structural unit.

TRPV4 and chloride channels mediate volume sensing in trabecular meshwork cells.

Aqueous humor drainage from the anterior eye determines intraocular pressure (IOP) under homeostatic and pathological conditions. Swelling of the trabecular meshwork (TM) alters its flow resistance but the mechanisms that sense and transduce osmotic gradients remain poorly understood. We investigated TM osmotransduction and its role in calcium and chloride homeostasis using molecular analyses, optical imaging, and electrophysiology. Anisosmotic conditions elicited proportional changes in TM cell volume, with swelling, but not shrinking, evoking elevations in intracellular calcium concentration [Ca2+]TM. Hypotonicity-evoked calcium signals were sensitive to HC067047, a selective blocker of TRPV4 channels, whereas the agonist GSK1016790A promoted swelling under isotonic conditions. TRPV4 inhibition partially suppressed hypotonicity-induced volume increases and reduced the magnitude of the swelling-induced membrane current, with a substantial fraction of the swelling-evoked current abrogated by Cl- channel antagonists 4,4'-diisothiocyanato-2,2'-stilbenedisulfonic acid (DIDS) and niflumic acid. The transcriptome of volume-sensing chloride channel candidates in primary human was dominated by ANO6 transcripts, with moderate expression of ANO3, ANO7, and ANO10 transcripts and low expression of LTTRC genes that encode constituents of the volume-activated anion channel. Imposition of 190 mosM but not 285 mosM hypotonic gradients increased conventional outflow in mouse eyes. TRPV4-mediated cation influx thus works with Cl- efflux to sense and respond to osmotic stress, potentially contributing to pathological swelling, calcium overload, and intracellular signaling that could exacerbate functional disturbances in inflammatory disease and glaucoma.NEW & NOTEWORTHY Intraocular pressure is dynamically regulated by the flow of aqueous humor through paracellular passages within the trabecular meshwork (TM). This study shows hypotonic gradients that expand the TM cell volume and reduce the outflow facility in mouse eyes. The swelling-induced current consists of TRPV4 and chloride components, with TRPV4 as a driver of swelling-induced calcium signaling. TRPV4 inhibition reduced swelling, suggesting a novel treatment for trabeculitis and glaucoma.

Cell Volume Regulation of Endothelial Cells Is Impaired in Keratoconus Cornea

In this work the permeability to water and urea of plasma membranes of endothelial cells of normal corneas and corneas with keratoconus was investigated. The endothelial cells were obtained from surgery material. Measurements of osmotic aqueous permeability (Pf) of endothelial cells in normal and in keratoconus did not reveal significant differences of this parameter in the two studied groups. The control cells and the cells from keratoconus cornea have similar osmotic water permeability (control cells, Pf = 0.53 ± 0.045 cm/s; keratoconus cells, Pf = 0.63 ± 0.041 cm/s; n = 25; p ≥ 0.05). Neither coefficient of urea permeability differed significantly in these groups (control, Pu = 0.049 ± 0.003 cm/s; keratoconus, Pu = 0.056 ± 0.003 cm/s; n = 25; p ≥ 0.05). Analysis of cell volume dynamics based on exponential approximation showed a more pronounced decrease of the cell volume of endothelial cells from keratoconus cornea in hypertonic medium in comparison with the cells from normal cornea. The increase of cell volume caused by isotonic entering of urea into the cells in hypertonic medium also was more pronounced in these cells in comparison with the normal ones. We conclude that there are significant changes in cell volume regulating mechanism in keratoconus cornea endothelial cells.

Structural Consequences of Different Metal Compositions in the Doped Spin‐Crossover Crystals [FezM1−z(bpp)2][BF4]2 (M = Ni, Zn; bpp = 2,6‐Bis{pyrazol‐1‐yl}pyridine)

Variable temperature crystallographic characterization of [FezZn1‒z(bpp)2][BF4]2 (bpp = 2,6‐bis{pyrazol‐1‐yl}pyridine; z = 0.88, 0.72 and 0.27) and [FezNi1‒z(bpp)2][BF4]2 (z = 0.83, 0.72 and 0.32) is presented. Comparison with previously published data confirms the isothermal unit cell volume change during spin‐crossover (ΔVSCO) behaves differently in the Zn‐ and Ni‐doped crystals. For the FeZn crystals, the relationship between ΔVSCO and z is continuous for z ≥ 0.3 but is steeper than expected, so ΔVSCO ≈ 0 for z = 0.27. In contrast ΔVSCO in the FeNi materials shows only a small variation between 0.83 ≥ z ≥ 0.46, before decreasing more strongly at higher dilution. ΔVSCO in each FeZn crystal is smaller than for its FeNi analogue with a similar composition. As well as the dopant ion ionic radius, the smaller ΔVSCO for the Zn‐doped materials reflects their T½ values, which are lower than for their FeNi counterparts. The contribution of T½ to this behavior is especially evident at high metal dilution.

Effect of Anterior Uveitis on Corneal Endothelial Cells

Objective: Investigating the impact of anterior uveitis on changes occurring in corneal endothelial cells. Methods: In this prospective cross-sectional study (cases and controls), the research sample included 43 patients (86 eyes) from the ophthalmic clinic attendees at Tishreen University Hospital in Latakia during the period 2023-2024. Results: The average corneal endothelial cell count was lower in the anterior uveitis group, both granulomatous (2074.16±173.70 cells/mm²) and nongranulomatous (2188.38±165.7 cells/mm²) types, compared to the control group (2696.1±136.60 cells/mm²) with a (p-value &lt;0.01) in all age groups studied. The average percentage of hexagonal cells was lower in the both granulomatous (42.41±2.6%) and non- granulomatous (47.0±2.2%) types, compared to the control group (61.4±2.0%) with a (p-value &lt;0.01) in all age groups studied. The average cell volume change coefficient was higher in the anterior uveitis group, both granulomatous (40.16±2.1) and non-granulomatous (34.70±1.08) types, compared to the control group (29.8±1.36) with a (p-value &lt;0.01) in all age groups studied. Host and disease-related characteristics had no effect on the measured results) p-value=0.184(. ECC was negatively correlated to the duration of uveitis (a=-0.513; p-value&lt;0.001), maximum intraocular pressure during the course of disease (a=-0.472; p-value = 0.0001), and the number of attacks (a=-0.515; p-value&lt;0.001). Conclusion: Corneal endothelial cells are affectd in patients with anterior uveitis, and this negative impact increases with the duration of the disease, the number of attacks, and the presence of elevated intraocular pressure. This negative impact is more pronounced in granulomatous uveitis.

RhoB plays a central role in hyperosmolarity-induced cell shrinkage in renal cells.

The small Rho GTP-binding proteins are important cell morphology, function, and apoptosis regulators. Unlike other Rho proteins, RhoB can be subjected to either geranylgeranylation (RhoB-GG) or farnesylation (RhoB-F), making that the only target of the farnesyltransferase inhibitor (FTI). Fluorescence resonance energy transfer experiments revealed that RhoB is activated by hyperosmolarity. By contrast, hyposmolarity did not affect RhoB activity. Interestingly, treatment with farnesyltransferase inhibitor-277 (FTI-277) decreased the cell size. To evaluate whether RhoB plays a role in volume reduction, renal collecting duct MCD4 cells and Human Kidney, HK-2 were transiently transfected with RhoB-wildtype-Enhance Green Fluorescence Protein (RhoB-wt-EGFP) and RhoB-CLLL-EGFP which cannot undergo farnesylation. A calcein-based fluorescent assay revealed that hyperosmolarity caused a significant reduction of cell volume in mock and RhoB-wt-EGFP-expressing cells. By contrast, cells treated with FTI-277 or expressing the RhoB-CLLL-EGFP mutant did not properly respond to hyperosmolarity with respect to mock and RhoB-wt-EGFP expressing cells. These findings were further confirmed by 3D-LSCM showing that RhoB-CLLL-EGFP cells displayed a significant reduction in cell size compared to cells expressing RhoB-wt-EGFP. Moreover, flow cytometry analysis revealed that RhoB-CLLL-EGFP expressing cells as well as FTI-277-treated cells showed a significant increase in cell apoptosis. Together, these data suggested that: (i) RhoB is sensitive to hyperosmolarity and not to hyposmolarity; (ii) inhibition of RhoB farnesylation associates with an increase in cell apoptosis, likely suggesting that RhoB might be a paramount player controlling apoptosis by interfering with responses to cell volume change.

Innovative, Three-Dimensional Model for Time-Dependent, Mechanical Battery Module Behaviour Due to Cell Volume Change

Innovative, Three-Dimensional Model for Time-Dependent, Mechanical Battery Module Behaviour Due to Cell Volume Change

Impact of trypsin on cell cytoplasm during detachment of cells studied by terahertz sensing

Trypsin is a very common enzyme used in cell culture to harvest cells by cleaving the proteins responsible for cell adhesion. However, trypsin also induces undesirable effects on cells, such as altering membrane proteins and the cytoskeleton, changing the composition of the cytoplasm and the cell volume, and even leading to cell death when used improperly. Using attenuated total reflection in the terahertz domain, confocal microscopy, and the propidium iodide test, we quantified in real time the change in cytoplasmic content induced by trypsin proteolysis on Madin-Darby canine kidney epithelial cells. We have observed a cytoplasmic modification from the very first seconds of trypsinization, following the change of cell volume due to mechanical re-equilibrium of the membrane. We found that the cytoplasmic alteration is associated with a transfer of small solutes: electrolytes and metabolites. We also found a very good nonlinear correlation between the side effects monitored by terahertz sensing and the cell height, regardless of the dependence of the cell height on trypsin concentration and exposure time.

Mechanosynthesis and microstructural characterization of F− and CO32− mono- and co-substituted hydroxyapatite

An investigation into the microstructural properties and mechanosynthesis mechanisms of three distinct calcium phosphate compounds, namely, carbonate-substituted hydroxyapatite (CHA), fluorapatite (FA), and carbonate- and fluoride-substituted hydroxyapatite (CFHA), was undertaken in this study. Significant insights into the crystalline structures of CHA, FA, and CFHA were revealed through Rietveld refinement analysis. In the CaCO3‒Ca(OH)2‒P2O5 ternary system, the transformation of the biphasic structure composed of CHA and dicalcium phosphate anhydrous (DCPA) into a single-phase A-type CHA was observed as milling duration increased. In the CaO‒Ca(OH)2‒CaF2‒P2O5 quaternary system, the formation of FA was influenced by milling time, and within 1‒5 h, a composite structure was formed. The progression from a composite structure to the formation of fully crystalline nanosized CFHA was also observed over the same milling periods in the CaCO3‒Ca(OH)2‒CaF2‒P2O5 quaternary system. The central finding highlights the substantial influence of milling time on the structural properties of the mechanosynthesized nanopowders, with marked changes in crystallite size, micro-strain, and unit cell volume being observed over different milling durations. The atomic coordinates and displacement parameters of the refined structures were also provided, revealing the presence of apatitic groups. Moreover, a detailed examination of the mechanochemical synthesis processes uncovered intricate sub-reactions that occur during ball milling. This work sets the stage for future investigations, facilitating a better grasp of their distinctive attributes and potential applications across various domains of regenerative medicine.

Sintesis Lapis Empat Fasa Aurivillius Ca1-xBaxBi3,5La0,5Ti4O15 Dengan Metode Lelehan Garam

The four-layer Aurivillius phase Ca1-xBaxBi3.5La0.5Ti4O15 (x = 0.2, 0.4, 0.6, 0.8, and 1) has been synthesized by molten salt method. The effect of varying x on the structure, morphology, and dielectric properties was studied. X-ray diffraction (XRD) and Le Bail refinement revealed that the compounds with the composition x = 0, 0.2, and 0.4 were single-phase product with orthorhombic A21am structure, whereas for higher x value (composition of Ba doped), a Ba2TiO4 impurity is found in products. Changes in unit cell volume were investigated, and the size increased with larger x. The substitution of larger Ba2+ ions resulted in a shorter Ti-O bond, shifting vibration mode to higher wave number that showed in FTIR spectra. SEM images show anisotropic plate-like grain with distributed particle sizes at 1.9 – 3.1μm. The dielectric constant values decrease with increasing x, otherwise the dielectric loss values increase for x = 0 and 0.2, however decrease for x = 0.4. The resulting Aurivillius compound has potential for applications in ferroelectric and piezoelectric devices.