Cell Suspension Research Articles

DIVERGENT PROPERTIES OF SKELETAL STEM CELLS FROM THE NECROTIC AND NON-NECROTIC ZONES OF FEMORAL HEADS IN OSTEONECROSIS OF THE FEMORAL HEAD

Bone marrow stem cells (BMSCs) represent a collection of different cell types exhibiting stem cell characteristics but with notable heterogeneity. Among these, Skeletal Stem Cells (SSCs) represent a distinct matrix subgroup within BMSC and demonstrate a specialized capacity to facilitate bone formation, recruit chondrocytes, and contribute to hematopoiesis. SSCs play a pivotal role in orchestrating the functions of skeletal organs. Local ischemia has a significant impact on cell survival and function. We hypothesize that bone ischemia induces alterations in the differentiation potential of SSCs, consequently influencing changes in bone structure.We mechanically dissected tissue from the necrotic segment in the femoral head and more normal appearing areas from the femoral neck of specimens from 5 patients diagnosed with osteonecrosis of the femoral head (ONFH). These tissues were enzymatically broken down into individual cell suspensions. Utilizing fluorescence-activated cell sorting (FACS) based on specific surface markers indicative of human skeletal stem cells (hSSC), namely CD45- CD235a- CD31- TIE2- Podoplanin (PDPN)+ CD146- CD73+ CD164+, we isolated a distinct cell population. Subsequent in vitro evaluations, focusing on clonogenicity, osteogenesis, and chondrogenesis were conducted to assess the functional prowess of these SSCs. Moreover, we introduced BMP2 at a concentration of 50ng/ml to SSCs extracted from necrotic regions to potentially reinstate their osteogenic capabilities.We effectively isolated SSCs from both Necrotic and Non-necrotic Zones. We observed an augmented clonal formation capacity and chondrogenesis ability of SSCs isolated from the necrotic region, accompanied by a significant decline in osteogenic ability (P＜0.01), an effect not reversible even with the addition of BMP2.Ischemia adversely affects the proliferation and function of SSCs, resulting in a diminished osteogenic capacity and an insensitivity to BMP2, ultimately leading to structural alterations in bone tissue.

Off-axis digital lensless holographic microscopy based on spatially multiplexed interferometry.

Digital holographic microscopy (DHM) is a label-free microscopy technique that provides time-resolved quantitative phase imaging (QPI) by measuring the optical path delay of light induced by transparent biological samples. DHM has been utilized for various biomedical applications, such as cancer research and sperm cell assessment, as well as for in vitro drug or toxicity testing. Its lensless version, digital lensless holographic microscopy (DLHM), is an emerging technology that offers size-reduced, lightweight, and cost-effective imaging systems. These features make DLHM applicable, for example, in limited resource laboratories, remote areas, and point-of-care applications. In addition to the abovementioned advantages, in-line arrangements for DLHM also include the limitation of the twin-image presence, which can restrict accurate QPI. We therefore propose a compact lensless common-path interferometric off-axis approach that is capable of quantitative imaging of fast-moving biological specimens, such as living cells in flow. We suggest lensless spatially multiplexed interferometric microscopy (LESSMIM) as a lens-free variant of the previously reported spatially multiplexed interferometric microscopy (SMIM) concept. LESSMIM comprises a common-path interferometric architecture that is based on a single diffraction grating to achieve digital off-axis holography. From a series of single-shot off-axis holograms, twin-image free and time-resolved QPI is achieved by commonly used methods for Fourier filtering-based reconstruction, aberration compensation, and numerical propagation. Initially, the LESSMIM concept is experimentally demonstrated by results from a resolution test chart and investigations on temporal stability. Then, the accuracy of QPI and capabilities for imaging of living adherent cell cultures is characterized. Finally, utilizing a microfluidic channel, the cytometry of suspended cells in flow is evaluated. LESSMIM overcomes several limitations of in-line DLHM and provides fast time-resolved QPI in a compact optical arrangement. In summary, LESSMIM represents a promising technique with potential biomedical applications for fast imaging such as in imaging flow cytometry or sperm cell analysis.

Dissociation of Human and Mouse Tumor Tissue Samples for Single-cell RNA Sequencing.

Human tumor samples hold a plethora of information about their microenvironment and immune repertoire. Effective dissociation of human tissue samples into viable cell suspensions is a required input for the single-cell RNA sequencing (scRNAseq) pipeline. Unlike bulk RNA sequencing approaches, scRNAseq enables us to infer the transcriptional heterogeneity in tumor specimens at the single-cell level. Incorporating this approach in recent years has led to many discoveries, such as identifying immune and tumor cellular states and programs associated with clinical responses to immunotherapies and other types of treatments. Moreover, single-cell technologies applied to dissociated tissues can be used to identify accessible chromatin regions T and B cell receptor repertoire, and the expression of proteins, using DNA barcoded antibodies (CITEseq). The viability and quality of the dissociated sample are critical variables when using these technologies, as these can dramatically affect the cross-contamination of single cells with ambient RNA, the quality of the data, and interpretation. Moreover, long dissociation protocols can lead to the elimination of sensitive cell populations and the upregulation of a stress response gene signature. To overcome these limitations, we devised a rapid universal dissociation protocol, which has been validated on multiple types of human and murine tumors. The process begins with mechanical and enzymatic dissociation, followed by filtration, red blood lysis, and live dead enrichment, suitable for samples with a low input of cells (e.g., needle core biopsies). This protocol ensures a clean and viable single-cell suspension paramount to the successful generation of Gel Bead-In Emulsions (GEMs), barcoding, and sequencing.

Dielectrophoretic characterization of peroxidized retinal pigment epithelial cells as a model of age-related macular degeneration

BackgroundAge-related macular degeneration (AMD) is a prevalent ocular pathology affecting mostly the elderly population. AMD is characterized by a progressive retinal pigment epithelial (RPE) cell degeneration, mainly caused by an impaired antioxidative defense. One of the AMD therapeutic procedures involves injecting healthy RPE cells into the subretinal space, necessitating pure, healthy RPE cell suspensions. This study aims to electrically characterize RPE cells to demonstrate a possibility using simulations to separate healthy RPE cells from a mixture of healthy/oxidized cells by dielectrophoresis.MethodsBPEI-1 rat RPE cells were exposed to hydrogen peroxide to create an in-vitro AMD cellular model. Cell viability was evaluated using various methods, including microscopic imaging, impedance-based real-time cell analysis, and the MTS assay. Healthy and oxidized cells were characterized by recording their dielectrophoretic spectra, and electric cell parameters (crossover frequency, membrane conductivity and permittivity, and cytoplasm conductivity) were computed. A COMSOL simulation was performed on a theoretical microfluidic-based dielectrophoretic separation chip using these parameters.ResultsIncreasing the hydrogen peroxide concentration shifted the first crossover frequency toward lower values, and the cell membrane permittivity progressively increased. These changes were attributed to progressive membrane peroxidation, as they were diminished when measured on cells treated with the antioxidant N-acetylcysteine. The changes in the crossover frequency were sufficient for the efficient separation of healthy cells, as demonstrated by simulations.ConclusionsThe study demonstrates that dielectrophoresis can be used to separate healthy RPE cells from oxidized ones based on their electrical properties. This method could be a viable approach for obtaining pure, healthy RPE cell suspensions for AMD therapeutic procedures.

Production and characterization of novel Anti-HIV Fc-fusion proteins in plant-based systems: Nicotiana benthamiana & tobacco BY-2 cell suspension

Multifunctional anti-HIV Fc-fusion proteins aim to tackle HIV efficiently through multiple modes of action. Although results have been promising, these recombinant proteins are hard to produce. This study explored the production and characterization of anti-HIV Fc-fusion proteins in plant-based systems, specifically Nicotiana benthamiana plants and tobacco BY-2 cell suspension. Fc-fusion protein expression in plants was optimized by incorporating codon optimization, ER retention signals, and hydrophobin fusion elements. Successful transient protein expression was achieved in N. benthamiana, with notable improvements in expression levels achieved through N-terminal hydrophobin fusion and ER retention signals. Stable expression in tobacco BY-2 resulted in varying accumulation levels being at highest 2.2.mg/g DW. The inclusion of hydrophobin significantly enhanced accumulation, providing potential benefits for downstream processing. Mass spectrometry analysis confirmed the presence of the ER retention signal and of N-glycans. Functional characterization revealed strong binding to CD64 and CD16a receptors, the latter being important for antibody-dependent cellular cytotoxicity (ADCC). Interaction with HIV antigens indicated potential neutralization capabilities. In conclusion, this research highlights the potential of plant-based systems for producing functional anti-HIV Fc-fusion proteins, offering a promising avenue for the development of these novel HIV therapies.

Differentiation potential of SOX2-positive stem cells in the bovine pituitary gland

The pituitary gland is the master endocrine gland, harboring stem cells with various genetic characteristics; however, data from non-rodent and non-human sources are scarce. In this study, we isolated putative stem cells from the bovine pituitary gland and investigated their potential for differentiation into hormone-producing cells. Immunohistochemical analysis revealed that in calves and heifers, stem cell marker sex-determining region Y-box 2 (SOX2)-positive cells were widely present in the pituitary gland and partially co-localized with anterior pituitary hormones. Next, a single-cell suspension of primary anterior lobe cells from bovines aged 0 and 12 months was subjected to two-dimensional culture. Consequently, some cells proliferated in the culture dishes. The expression levels of Sox2 and several other stem cell markers were higher in these cells after culture. In addition, almost all proliferating cells were positive for SOX2, whereas all were negative for hormones. In three-dimensional cultures, SOX2-positive cells presented a spheroid-like morphology and differentiated into endocrine cells. These results provide evidence that SOX2-positive cells are pituitary stem cells with the potential to differentiate into hormone-producing cells, regardless of age. Our data lay a theoretical foundation for further studies on controlling fundamental processes, such as body growth, reproduction, and lactation.

Therapeutically targeting the CALR/CD47 pathway in MPN to reactivate natural immunosurveillance mechanisms within the body to enhance treatment outcomes.

170 Background: MPNs are a group of related myeloid malignancies characterized by alterations in mature blood cell production/bone marrow environment and have a tendency to evolve into acute myeloid leukaemia. We demonstrated that CD47 blockade in combination with ruxolitinib, increased CALR expression enhancing cytotoxicity in vitro, promoting enhanced neoplastic clone clearance. With this study we describe a potential methodology for assessing effect of new compounds or combinations and the impact of modulating the immunoresponse upon myeloid malignant clones. Methods: Utilising HEL 92.1.7 and SET-2 cells (JAK2 mutated), Marimo cells (CALR mutated) and K562 cell line models; we will incubate with routine therapies (hydroxyurea, anagrelide, ruxolitinib) in combination with a range of anti-CD47 compounds (Anti-CD47 monocloncal antibodies, BET-1 inhibitors, SIRa inhibitor) and will determine the impact upon CD47 and CALR cell surface expression via flow cytometry. Monocyte derived macrophage (MDM) will be produced through Phorbol 12-myristate 13-acetate (PMA) differentiation of a monocytic Thp-1 cell line. Expression of macrophage cell surface markers (CD11b, CD14), as well as intracellular markers (CD68), will be detected by flow cytometry. MDM will then be polarized to either a pro-inflammatory M1, or anti-inflammatory M2 phenotype, with lipopolysaccharide/interferon gamma or interleukins 4 and 13, respectively. Co-culture experiments will then be undertaken to determine how different anti-CD47 therapy combination impact macrophage polarization and destruction of MPN cell lines. Results: We predict that CALR/CD47 levels on each cell line subtype will respond differently highlighting heterogeneity within MPNs and demonstrating the clear need for a more personalised immunotherapy approach. Alterations in JAK/STAT pathway and BET inhibition may hinder macrophage polarisation to the anti-tumorigenic M1 macrophage phenotype. We theorise that indirect co-culture of M1 macrophage with MPN suspension cells under different treatment modalities will enhance MPN cell death and decrease CD47 expression to a greater level than that which we expect to see in M2 polarised macrophage. We also anticipate that the M2 polarised macrophage, which dominate in the tumour microenvironment as MPN progresses, will fail to phagocytose MPN cells and may not be rescued by novel immunotherapeutics. Conclusions: Our group demonstrated the role of CD47 and CALR expression as a key mechanism and a potential target to enhance presentation of the cancer cell to the immune system, and we believe that understanding the interaction of CD47/CALR – macrophages, will drive new therapeutical approaches able to modulate the immune response and improve patients outcomes, potentially leading to complete MPN clone eradiation and cure.

Label-free, non-contact determination of resting membrane potential using dielectrophoresis

Measurement of cellular resting membrane potential (RMP) is important in understanding ion channels and their role in regulation of cell function across a wide range of cell types. However, methods available for the measurement of RMP (including patch clamp, microelectrodes, and potential-sensitive fluorophores) are expensive, slow, open to operator bias, and often result in cell destruction. We present non-contact, label-free membrane potential estimation which uses dielectrophoresis to determine the cytoplasm conductivity slope as a function of medium conductivity. By comparing this to patch clamp data available in the literature, we have demonstratet the accuracy of this approach using seven different cell types, including primary suspension cells (red blood cells, platelets), cultured suspension cells (THP-1), primary adherent cells (chondrocytes, human umbilical mesenchymal stem cells), and adherent (HeLa) and suspension (Jurkat) cancer cell lines. Analysis of the effect of ion channel inhibitors suggests the effects of pharmaceutical agents (TEA on HeLa; DMSO and neuraminidase on red blood cells) can also be measured. Comparison with published values of membrane potential suggest that the differences between our estimates and values recorded by patch clamp are accurate to within published margins of error. The method is low-cost, non-destructive, operator-independent and label-free, and has previously been shown to allow cells to be recovered after measurement.

Elicitation and precursor induced approaches for the enhancement of α−tocopherol production using suspension cultures of Solanum lycopersicum

Elicitation and precursor feeding are the effective strategies for enhancing the synthesis of bioactive compounds in plant cell suspension cultures. The present study aimed to explore an efficient elicitation and precursor feeding protocol and its effect on inducing the accumulation of α-tocopherol in Solanum lycopersicum (tomato) suspension cell culture. The tomato cell suspension cultures were treated with different elicitors (Methyl Jasmonate, Salicylic acid and Yeast extract) and precursors (Homogentisic acid, Tyrosine, Hydroxypyruvic acid and Phytol) and the effect of α-tocopherol production was studied. Significant increase in the α-tocopherol was observed on day 5 upon methyl jasmonate treatment which represented 17.7 fold increase in comparison to the control. The treatment of precursor in combination viz., 150 μM Homogentisic acid + 150 μM Phytol showed the maximum enhancement of α-tocopherol up to 22 fold on day 10 compared to the untreated control. These results suggested that the suspension cultures combining with the optimal precursor feeding and elicitors enhanced the production of α-tocopherol in economically important tomato cell cultures.

Metagenomes, metagenome-assembled genomes, and metatranscriptomes from a chlorinated ethene-dechlorinating culture amended with biochar pyrolyzed at different temperatures.

We investigated the effects of biochar and pyrolysis temperature on a chlorinated ethene-dechlorinating anaerobic consortium. Sequencing of nucleic acids from suspended and biochar-attached cells yielded 9 metagenomes, 122 metagenome-assembled genomes, and 18 metatranscriptomes that provide insights into the structure, function, activity, and interactions of the dehalogenating consortium with biochar.

Prediction of the clinical supply of blood components in Xi'an City from 2023 to 2025

Objective: To construct a prediction model for the clinical supply of blood components in Xi'an City from 2023 to 2025. Methods: Based on the blood supply data of the Blood Management Information System of Shaanxi Provincial Blood Center from January 2013 to December 2022, a gray prediction model and an exponential curve fitting model were used to construct the prediction model, and the optimal prediction model was determined according to the error parameters of the relevant indicators of the model. The supply of blood components in Xi'an from 2023 to 2025 was predicted. Results: The fitting equations of the exponential curve fitting model to predict the supply of suspended red blood cells, platelets and cryoprecipitate in Xi'an were, x（1）（t+1）=1.16e0.04t，x（1）（t+1）=1.04e0.12t and x（1）（t+1）=1.01e1.10t, respectively. The mean absolute errors (mean relative errors) of the exponential curve fitting model in predicting the supply of suspended red blood cells, platelets and cryoprecipitate in Xi'an were 10 488.7 (0.05%), 2 114.9 (0.08%) and 3 089.6 (0.07%), respectively, which were lower than those of the gray prediction model, about 10 488.7 (3.44%), 2 152.78 (8.20%) and 3 441.35 (7.92%), respectively. The exponential curve fitting model predicted that the clinical supply of blood components in Xi'an would increase year by year from 2023 to 2025, and the clinical supply of suspended red blood cells, platelets, and cryoprecipitate in Xi'an would increase to 409 467 U, 69 818 therapeutic volume and 94 724 U, respectively by 2025. Conclusion: The exponential curve fitting model can make a good prediction of the clinical supply of blood components in Xi'an City.

Gentiana capitata Buch.-Ham. ex D.Don Cell Suspension Culture as a New Source of Isosaponarin and 3,7,8-Trimethoxy-9-oxo-9H-xanthen-1-yl 6-O-β-D-ribopyranosyl-β-D-allopyranoside and Their Effect on PC-12 Cell Viability.

Some species of the Gentianaceae family are a valuable source of secondary metabolites. However, the phytochemical knowledge of some of these species remains insufficient. Therefore, this work focused on the isolation of the two main secondary metabolites in the methanolic extract from a Gentiana capitata cell suspension using preparative HPLC and the determination of their structure using UHPLC-DAD-IT-MS/MS and NMR methods. Their content in the methanolic extract was quantified using a previously validated HPLC method. The toxicity of the extract and two isolated compounds was also tested on the PC-12 cell line. The structures of the main secondary metabolites were identified as isosaponarin and 3,7,8-Trimethoxy-9-oxo-9H-xanthen-1-yl 6-O-β-D-ribopyranosyl-β-D-allopyranoside by comparing the UHPLC-DAD-IT-MS/MS and NMR results with the literature data. The content of isosaponarin was determined to be 0.76 ± 0.04%, and the content of 3,7,8-trimethoxy-9-oxo-9H-xanthen-1-yl 6-O-β-D-ribopyranosyl-β-D-allopyranoside was found to be 0.31 ± 0.02% in the dry extract. Additionally, a two-fold increase in the viability of the PC-12 cell line was observed compared to the control after treatment with the methanolic extract at a concentration of 500 µg/mL. These results suggest the potential use of G. capitata cell suspension methanolic extract as a new source of isosaponarin and 3,7,8-trimethoxy-9-oxo-9H-xanthen-1-yl 6-O-β-D-ribopyranosyl-β-D-allopyranoside, highlighting their lack of toxicity to the PC-12 (rat pheochromocytoma) cell line.

Spontaneous cytokine production by the cells from peripheral blood, lymph nodes, spleen, thymus and skin in a murine model of acute psoriasis-like dermatitis

Imiquimod-induced model of psoriasis in mice is used for the studies in psoriasis. Imiquimod administered as skin application triggers a complex multi-stage process simulating psoriatic inflammation of the skin, accompanied by changes in production of cytokines. The aim of this work was a comprehensive study of their contents in cell supernatants isolated from skin, blood, from central and peripheral lymphoid organs and the effect of imiquimod on these parameters. Forty-six C57BL/6 mice were divided into two groups: (1) control (n = 22), and (2) experimental (n = 24). Development of experimental pathology was evaluated by van de Fits et al. The mice from experimental group were treated with a cream containing 5% imiquimod (62.5 mg/ cm2/ day/mouse) for 7 days. On the 7th day of experiment, the animals were subject to blood sampling, extraction of spleen, lymph nodes, thymus, and skin biopsies were also made. To obtain cell suspensions, the tissues of spleen, lymph nodes, and thymus were crushed in a homogenizer, and then passed through cell filters (50 mcm pore size). The method of spontaneous migration was used to isolate skin cells. The cultures of blood, spleen, lymph nodes, thymus, and skin cells were incubated for 24 hours in RPMI-1640 followed by assessment of spontaneous cytokine production in supernatants. The cytokine level (IFNγ, IL-1β, IL-5, IL-6, IL-10, IL- 17, TNFα, IL-10) was determined using the murine Th1/Th2/Th17 Panel test system. Our study revealed that the cells isolated from blood and lymphoid organs synthesize increased amounts of pro-inflammatory cytokines: IL-1 and IL-17. The most pronounced changes in the cytokine profile are observed in cell supernatants from blood, skin and spleen cultures.

Enhancing Withanolide Production in the Withania Species: Advances in In Vitro Culture and Synthetic Biology Approaches.

Withanolides are naturally occurring steroidal lactones found in certain species of the Withania genus, especially Withania somnifera (commonly known as Ashwagandha). These compounds have gained considerable attention due to their wide range of therapeutic properties and potential applications in modern medicine. To meet the rapidly growing demand for withanolides, innovative approaches such as in vitro culture techniques and synthetic biology offer promising solutions. In recent years, synthetic biology has enabled the production of engineered withanolides using heterologous systems, such as yeast and bacteria. Additionally, in vitro methods like cell suspension culture and hairy root culture have been employed to enhance withanolide production. Nevertheless, one of the primary obstacles to increasing the production of withanolides using these techniques has been the intricacy of the biosynthetic pathways for withanolides. The present article examines new developments in withanolide production through in vitro culture. A comprehensive summary of viable traditional methods for producing withanolide is also provided. The development of withanolide production in heterologous systems is examined and emphasized. The use of machine learning as a potent tool to model and improve the bioprocesses involved in the generation of withanolide is then discussed. In addition, the control and modification of the withanolide biosynthesis pathway by metabolic engineering mediated by CRISPR are discussed.

Influence of the Culture Conditions on Camellia sinensis Cell Cultures.

Since the last century, it has been shown that dedifferentiated cells of Camellia sinensis can produce catechins and other secondary metabolites under in vitro conditions, with potential applications in the cosmetic, pharmaceutical and food industries. In this work, cell suspension cultures of a C. sinensis cell line (LSC-5Y) were established in a liquid medium in order to optimize the biomass productivity, catechin monomer (GC, EGC, C, EC, CG, and ECG) and alkaloid (TB and CAF) productivity. The following factors were evaluated: concentration of growth regulators (BA and IBA), inoculum size, age of the cell line, light exposure, and effect of biotic elicitors (MeJA and extracts of Ciborinia camelliae). GC, EGC, and ECG increased approximately 1.80-fold when the auxin IBA concentration was increased from 0.1 to 2.0 mg/L. In addition, better productivity of EGC, C, EC, and CAF was achieved by using inoculum densities between 50 and 100 g/L. Although lower inoculum densities (25 g/L) showed a higher growth rate (0.20 d-1), the use of inoculum densities higher than 25 g/L favors a 2-4-fold increase in total catechin (TC) productivity, with maximum productivity being reached after 21 days of culture. However, the cell line showed instability in TC productivity: in the short term (in three successive subcultures), the coefficient of variation was 32.80%, and catechin production capacity was 2.5 years with maximum productivity at 0.5 years. Finally, it was observed that ethanol, used as an elicitor solvent, has a strong elicitor effect capable of increasing the accumulation of catechins up to 5.24 times compared to the treatment without an elicitor.

Particle-based modeling and GPU-accelerated simulation of cellular blood flow

Computational modeling and simulation of cellular blood flow is highly desired for understanding blood microcirculation and blood-related diseases such as thrombosis and tumor, but it remains a challenging task primarily because blood in microvessels should be described as a dense suspension of different types of deformable cells. The focus of the present work is on the development of a particle-based and GPU-accelerated numerical method that is able to quickly simulate the various behaviors of deformable cells in three-dimensional arbitrarily complex geometries. We employ a two-fluid model to describe blood flow, incorporating the deformation and aggregation of cells. A smoothed dissipative particle dynamics is used to solve the two-fluid model, and a discrete microstructure model is applied for the cell deformation, as well as a Morse potential model for the cell aggregation. The heterogeneous CPU-GPU environment is established, where each GPU thread is dedicated to a particle, and the CPU is mainly responsible for loading and exporting data. Five test cases are conducted against analytical theory, experimental data, and previous numerical results, for pure fluid, cell deformation, cell aggregation, cell suspension and the cellular flow in a complex network, respectively. It is shown that the methodology can accurately predict various behaviors of cells, and the GPU is well suited for particle-based modeling. Especially for cellular blood flow, where calculating cellular forces is a compute-intensive and time-consuming task, the GPU offers exceptional parallel capabilities, significantly enhancing the simulation efficiency. The speedup is about 3.5 times faster than the CPU parallelization with 96 cores for the pure fluid, and this acceleration nearly reaches 20 times when cells are included in the simulations. Particularly, the calculations for deformation and aggregation forces demonstrate a substantial speedup, achieving the improvements of up to 120 and 640 times, respectively, compared to their serial counterparts. The present methodology can effectively integrate various behaviors of cells, and has the potential in simulating very large microvascular networks at organ levels.

Heraclenin promotes the osteogenic differentiation of bone marrow stromal cells by activating the RhoA/ROCK pathway.

Osteoporosis is a devastating skeletal disease, the pathogenesis of which is related to abnormal bone metabolism, featured by the imbalance between osteoblastic bone formation and osteoclastic bone resorption. Stem cell-based therapies have been demonstrated to improve osteoporosis treatment. Previously, the linear furanocoumarin heraclenin was reported to enhance osteoblast differentiation and mineralization in mouse mesenchymal stem cells (MSCs), suggesting its potential for osteogenic differentiation and bone regeneration. Our study was designed to confirm the promotive role of heraclenin on osteogenic differentiation of human bone MSCs (BMSCs) and explore the underlying mechanisms. Human BMSCs were treated for 24, 48, and 72h with heraclenin (5, 10, 20, 40, and 80 μM), and cell viability was determined by Cell Counting Kit-8 (CCK-8) assay. To further evaluate the cytotoxicity of heraclenin, cell suspension obtained from BMSCs treated with heraclenin (5, 10, and 20 μM) for 72h was subjected to a MUSE™ cell analyzer for cell viability and count assay. BMSCs were incubated in osteogenic induction medium for 7 days. Then, osteogenic differentiation and mineralization of BMSCs were assessed through alkaline phosphatase (ALP) and Alizarin Red S staining. The expression of osteogenesis markers including ALP, osteocalcin (OCN), osterix (OSX), and runt-related transcription factor 2 (RUNX2) was detected via reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting. The effects of heraclenin on the RhoA/ROCK pathway were estimated through western blotting. Y-27632, the ROCK inhibitor, was used to confirm the role of the RhoA/ROCK pathway in heraclenin-mediated osteogenic differentiation of BMSCs. Heraclenin (5-80 μM) was non-toxic on human BMSCs. Heraclenin treatment (5-20 μM) dose-dependently enhanced ALP activity and calcium deposition. Furthermore, heraclenin promoted ALP, OCN, OSX, and RUNX2 mRNA and protein expression. Mechanically, heraclenin treatment increased RhoA and ROCK1 mRNA expression, stimulated the translocation of ROCK from the cytosolic to the membrane fraction, and elevated the protein levels of phosphorylated cofilin (p-cofilin) and active RhoA. Additionally, treatment with Y-27632 overturned the promotion of heraclenin on ALP activity, calcium deposition, the expression of osteogenesis markers, and the RhoA/ROCK signaling pathway. Heraclenin facilitates the osteogenic differentiation of human BMSCs through the activation of the RhoA/ROCK pathway.

Controlling Pericellular Oxygen Tension in Cell Culture Reveals Distinct Breast Cancer Responses to Low Oxygen Tensions.

In oxygen (O2)-controlled cell culture, an indispensable tool in biological research, it is presumed that the incubator setpoint equals the O2 tension experienced by cells (i.e., pericellular O2). However, it is discovered that physioxic (5% O2) and hypoxic (1% O2) setpoints regularly induce anoxic (0% O2) pericellular tensions in both adherent and suspension cell cultures. Electron transport chain inhibition ablates this effect, indicating that cellular O2 consumption is the driving factor. RNA-seq analysis revealed that primary human hepatocytes cultured in physioxia experience ischemia-reperfusion injury due to cellular O2 consumption. A reaction-diffusion model is developed to predict pericellular O2 tension a priori, demonstrating that the effect of cellular O2 consumption has the greatest impact in smaller volume culture vessels. By controlling pericellular O2 tension in cell culture, it is found that hypoxia vs. anoxia induce distinct breast cancer transcriptomic and translational responses, including modulation of the hypoxia-inducible factor (HIF) pathway and metabolic reprogramming. Collectively, these findings indicate that breast cancer cells respond non-monotonically to low O2, suggesting that anoxic cell culture is not suitable for modeling hypoxia. Furthermore, it is shown that controlling atmospheric O2 tension in cell culture incubators is insufficient to regulate O2 in cell culture, thus introducing the concept of pericellular O2-controlled cell culture.

In Vitro Superparamagnetic Hyperthermia Employing Magnetite Gamma-Cyclodextrin Nanobioconjugates for Human Squamous Skin Carcinoma Therapy.

In vitro alternative therapy of human epidermoid squamous carcinoma (A431) by superparamagnetic hyperthermia (SPMHT) using Fe3O4 (magnetite) superparamagnetic nanoparticles (SPIONs) with an average diameter of 15.8 nm, bioconjugated with hydroxypropyl gamma-cyclodextrins (HP-γ-CDs) by means of polyacrylic acid (PAA) biopolymer, is presented in this paper. The therapy was carried out at a temperature of 43 °C for 30 min using the concentrations of Fe3O4 ferrimagnetic nanoparticles from nanobioconjugates of 1, 5, and 10 mg/mL nanoparticles in cell suspension, which were previously found by us to be non-toxic for healthy cells (cell viabilities close to 100%), according to ISO standards (cell viability must be greater than 70%). The temperature for the in vitro therapy was obtained by the safe application (without exceeding the biological limit and cellular damage) of an alternating magnetic field with a frequency of 312.4 kHz and amplitudes of 168, 208, and 370 G, depending on the concentration of the magnetic nanoparticles. The optimal concentration of magnetic nanoparticles in suspension was found experimentally. The results obtained after the treatment show its high effectiveness in destroying the A431 tumor cells, up to 83%, with the possibility of increasing even more, which demonstrates the viability of the SPMHT method with Fe3O4-PAA-(HP-γ-CDs) nanobioconjugates for human squamous cancer therapy.

Advanced Microfluidic Platform for Tumor Spheroid Formation and Cultivation Fabricated from OSTE+ Polymer

In the evolving landscape of cancer research, 3D cell cultures, particularly tumor cell spheroids, are increasingly preferred in drug screening due to their enhanced mimicry of in vivo tumor environments, especially in drug resistance aspects. However, the consistent formation of uniform spheroids and their precise manipulation remain complex challenges. Among various methodologies, droplet microfluidics emerges as a highly effective approach for tumor spheroid formation. This paper introduces a novel, multifaceted microfluidic system that streamlines the entire spheroid cultivation process: (i) generating tumor spheroids from cell suspensions within individual droplets, (ii) merging these droplets into a continuous aqueous phase once spheroid formation is complete, and (iii) transferring the spheroids to a specialized cultivation area within the chip, equipped with trapping elements for extended cultivation in perfusion mode. Remarkably, this process requires no hydrogel encapsulation or external handling, as all operations are conducted within the microfluidic chip. Fabricated from the innovative OSTE+ (off-stoichiometry thiol-ene epoxy) polymer, the chip is designed for repeated use. To show its efficacy, we successfully formed spheroids from MCF-7, GAMG, and U87 cell lines in our system and compared them with spheroids prepared by a traditional agarose microwell method. Additionally, our methodology has successfully enabled the in-chip release of spheroids from droplets, followed by their effective trapping for subsequent cultivation, a process we have exemplified with MCF-7 spheroids. To our knowledge, this research represents the first instance of a fully integrated droplet microfluidic platform achieving scaffoldless tumor spheroid formation and handling. Our method holds promise for improving high-throughput, automated procedures in the formation, transfer, and cultivation of tumor cell spheroids.Graphical abstract