Cellular Construction Research Articles

Staphylococcus aureus major cell division protein FtsZ assembly is inhibited by silibinin, a natural flavonolignan that also blocked bacterial growth and biofilm formation

The bacterial cell division protein FtsZ has been considered a potential therapeutic target due to its rapid treadmilling that induces cellular wall construction in bacteria. The current study discovered a novel antimicrobial compound, silibinin, a natural flavonolignan and its impact on the recombinant S. aureus FtsZ (SaFtsZ). Silibinin inhibited S. aureus Newman growth in a dose-dependent manner. The IC50 and MIC values for silibinin were 75 μM and 200 μM, respectively. It had no cytotoxicity against HEK293 cells in vitro. Silibinin also enlarged the bacterial cell morphology by ∼40 folds and showed antibiofilm property. It perturbed the S. aureus membrane potential both at IC50 conc. and at MIC conc. Further, it inhibited both the polymerization and GTPase activity of SaFtsZ. It did not inhibit tubulin assembly, a eukaryotic FtsZ homolog. A fluorescence quenching study yielded the Kd value for SaFtsZ-Silibinin interaction and binding stoichiometry 0.857 ± 0.188 μM and 1:1, respectively. Both in silico study and competition assay indicated that silibinin binds at the GTP binding site on SaFtsZ. The Ki value for the silibinin-mediated inhibition of SaFtsZ was 8.8 μM. Therefore, these findings have comprehensively shown the antimicrobial behavior of silibinin on S. aureus Newman cells targeting SaFtsZ.

“GC-MS profiling, sub-acute toxicity study and total phenolic and flavonoid content analysis of methanolic leaf extract of Schima wallichii (D.C.) Korth-a traditional antidiabetic medicinal plant”

Ethnopharmacological relevanceSchima wallichii (D.C.) Korth is traditionally used in Manipur, India for treatment of diabetes and hypertension. However, there is no data reported regarding safety profile of this medicinal plant upon repeated per oral administration over a period of time. Aim of the studyIn the current study phytochemical profile, toxicological profile and total phenolic and flavonoid compound content of Schima wallichii leaves extract were evaluated. Materials and methodsGas chromatography coupled to mass spectrometry was performed for chemical profiling by using Gas Chromatography-Mass Spectrometry/Mass Spectrometry (GC-MS/MS), Shimadzu, TQ8040 system. A 28 days sub-acute toxicity study was carried out using albino Wistar rats by administering 3 different doses (200, 400 and 800 mg/kg body weight per oral) of methanol leaves extract. Changes in body weights were recorded weekly. Serum biochemical parameters were estimated as well as blood-cell count was done to check the effect of extract on haematopoietic system. Histopathology of vital organs viz. kidney, heart, brain, liver was performed to find any pathological indications. Since, liver is main the site for xenobiotic metabolism, estimation of the level of glutathione, catalase and lipid peroxidation were done. Further, total phenolic and flavonoid compound content estimation was performed for the leaves extract. ResultsGC-MS revealed 14 major compounds with area percentage >1% of which quinic acid, n-Hexadecanoic acid, 9,12,15-Octadecatrienoic acid, (Z,Z,Z)-, Octatriacontyl trifluoroacetate, are three major compounds. No mortality was observed after the treatment with extract. Blood-cell count and biochemical parameters didn't show significant deviation as compared to control group. Histopathology study of vital organs viz. (liver, kidney, heart and brain) showed normal cellular construction comparing to control group. There was no sign of membrane lipid peroxidation, depletion of catalase level and glutathione level in liver. The result demonstrates that NOAEL (no-observed-adverse-effect levels) in the sub-acute toxicity was above 800 mg/kg. The leaves extract showed significant total phenol and flavonoid content. ConclusionThe present study revealed that Schima wallichii possessed important bioactive compounds with therapeutic values. The plant was safe for consumption after repeated high doses administration in rats and possesses significant amount of total phenol and flavonoid content.

Development of cellular construction material-based flax shives: Physico-mechanical and thermal characterisation

The reduction of energy consumption in construction, production of thermal insulation materials, and the solution of environmental problems by recycling by-product derived several industrial sectors are becoming greater problems. In this context, vegetable by-products are an excellent alternative product to substitute mineral aggregates because they are easily available and renewable low-cost raw materials, and have higher advantage for economy and environment concerns. The viability of using vegetable materials such as flax shives for developing a sustainable Lightweight Cellular Construction Material (LCCM) is investigated in this paper. The produced material containing different volumes of flax shives (0V (control specimen), 1V, and 2V) was lightened by creating a porous structure in the matrix through a chemical reaction between Aluminium powder and free lime from pre-formulated Tradical PF70 binder. A study conducted on hardened material properties has indicated a significant reduction in sample unit weight, thereby resulting in a level of compressive strength compatible with a load-bearing wall. The reduction in flexural strength was lower than that in compressive strength. This study has also highlighted the effect of the porous structure on the thermal conductivity that lead to provide a high degree of thermal insulation. These results show that the cellular material based on flax particle can be used as suitable insulated load-bearing walls.

New Class of Genes in D. melanogaster (Conditional Mutations, Ontogenes, and Biological Role of Ontogenes)

The review briefs the history of the search for non-Mendelian genes, including the rationale for their existence and the methods for their discovery in D. melanogaster. The genes are named ontogenes and their mutations, conditional mutations. Characteristic features of conditional mutations in hybridological experiments have been described. Three separate sections dwell on the experimental facts that distinctly outline the difference of this novel group of genes from the classical protein-coding (Mendelian) genes. According to these facts, the specificity in the function of ontogenes consists in (1) the warrant that an organism belongs to a particular species; (2) the control of cellular construction; and, most likely, (3) the presence of nonchemical (biophysical) way of interaction between ontogenes

Flexible MXene/Nanocellulose Composite Aerogel Film with Cellular Structure for Electromagnetic Interference Shielding and Photothermal Conversion.

With the rapid development of wearable devices and integrated systems, protection against electromagnetic waves is an issue. For solving the problems of poor flexibility and a tendency to corrode traditional electromagnetic interference (EMI) shielding materials, two-dimensional (2D) nanomaterial MXene was employed to manufacture next-generation EMI shielding materials. Vacuum-assisted filtration combined with the liquid nitrogen prefreezing strategy was adopted to prepare flexible MXene/cellulose nanofibers (CNFs) composite aerogel film with unique cellular structure. Here, CNFs were employed as the reinforcement, and such a cellular structure design can effectively improve the shielding effectiveness (SE). In particular, the composite shows an outstanding EMI SE of 54 dB. Furthermore, the MXene/CNFs composite aerogel film exhibited prominent and steady photothermal conversion ability, which could obtain the maximum equilibrium temperature of 89.4 °C under an 808 nm NIR laser. Thus, our flexible composite aerogel film with appealing cellular construction holds great promise for wearable EMI shielding materials and heating applications in a cold and complex practical environment.

Simultaneous 3D Construction and Imaging of Plant Cells Using Plasmonic Nanoprobe-Assisted Multimodal Nonlinear Optical Microscopy.

Nonlinear optical (NLO) imaging has emerged as a promising plant cell imaging technique due to its large optical penetration, inherent 3D spatial resolution, and reduced photodamage; exogenous nanoprobes are usually needed for nonsignal target cell analysis. Here, we report in vivo, simultaneous 3D labeling and imaging of potato cell structures using plasmonic nanoprobe-assisted multimodal NLO microscopy. Experimental results show that the complete cell structure can be imaged via the combination of second-harmonic generation (SHG) and two-photon luminescence (TPL) when noble metal silver or gold ions are added. In contrast, without the noble metal ion solution, no NLO signals from the cell wall were acquired. The mechanism can be attributed to noble metal nanoprobes with strong nonlinear optical responses formed along the cell walls via a femtosecond laser scan. During the SHG-TPL imaging process, noble metal ions that crossed the cell wall were rapidly reduced to plasmonic nanoparticles with the fs laser and selectively anchored onto both sides of the cell wall, thereby leading to simultaneous 3D labeling and imaging of the potato cells. Compared with the traditional labeling technique that needs in vitro nanoprobe fabrication and cell labeling, our approach allows for one-step, in vivo labeling of plant cells, thus providing a rapid, cost-effective method for cellular structure construction and imaging.

Lessons from nature [Biomimicry- Construction

Two finalists in the 2022 Ray of Hope Prize have looked to nature for innovative ways to transform the sector and improve the environmental impact of urban construction, ultimately making cities more sustainable. Biomimicry plays a key role in these innovations, with both Mycocycle and Metavoxel drawing inspiration from natural processes to create new solutions for the construction industry. Metavoxel has invented new composite building materials that have taken inspiration from the cellular construction of materials such as bone, wood, and sea sponge. These programmable, cellular building materials are based on discrete assembly of modular building-block parts. By leveraging the benefits of cellular architecture, Metavoxel can address a range of performance regimes with significantly less material while offering improved performance through application-specific tunability. This means that the construction industry can cut the cost of building projects and improve structural efficiency, as Metavoxel's cellular innovations are around 98% air but maintain a high level of structural performance. Mycocycle, on the other hand, works with fungi to break down complex construction waste materials. Inspired by biomimicry, Mycocycle not only processes the waste but also recycles it into building materials that can be used in new products. This innovative approach to waste management not only addresses the growing issue of unsustainable disposal of waste materials but also provides a sustainable source of building materials.

Ontogenes and Their Role in Cellular Construction

The genes referred to as ontogenes are responsible for conditional mutations. Based on the results of the research of conditional mutations in D. melanogaster, we attempt to figure out the biological role of ontogenes. We conclude that ontogenes in the process of individual development control the construction of the living organisms of cells (cellular construction), which comprises the induction of cell division, determination of division plane, and the location of daughter cells after the division is completed. The process of morphogenesis consists of cellular construction and protein synthesis. Protein synthesis is controlled by protein-coding (Mendelian) genes. Mendelian genes are switched on by ontogenes. In terms of the two-component genome composed of Mendelian genes and ontogenes, we consider 1) the concept of biological character; 2) interspecific incompatibility; 3) ontogenesis; 4) phylogenesis; and 5) mutagenesis. Ontogenes, which control cellular construction, possess the specific features unusual for Mendelian genes, namely, 1) the activity in germ line tissue; 2) remote interaction; and 3) activity in a compacted state (heterochromatization). These specific features of ontogenes suggest that unlike the Mendelian genes with their chemical activity, ontogenes possess another type of activity (biophysical) involving induction of an electromagnetic field.

Experimental Testing of Cellular Construction Materials Containing Flax Particles

The feasibility of a sustainable non-autoclaved cellular concrete, based on flax vegetable co-products, for the production of usable specimen in the lightweight construction field, has been investigated experimentally. The produced specimen, containing various volume ratios of flax particles with respect to preformulatd Tradical PF70 lime binder of 0, 1, and 2, were lightened by creating a porous structure in the matrix through the addition of 0.3% wt. Aluminium powder (able to react with calcium hydroxide from the binder and result in microscopic air-bubbles). Fresh and hardened specimen properties, including hydration, fresh density, porosity, hardened density, compressive and flexural strengths, toughness energy, and dry thermal conductivity at different temperatures, were assessed for varying flax-to-binder ratios. Results have shown that the addition of Aluminum powder leads to restrain the setting time delay of binder-based lime. Moreover, the hardened material displays a significant decrease in specimen density, thereby resulting in a compressive strength level compatible with that required in the cellular construction materials sector. Results also highlighted the ability of added flax to induce a change in the specimen from brittle to ductile behavior. Moreover, a high degree of thermal insulation can be achieved, which makes the cellular specimen based on flax particle suitable as insulated-bearing walls material.

Effect of copper and zinc ions on type I collagen self-assembly

Owing to their central roles in cellular signaling, construction, and biochemistry, collagen-collagen interactions, and collagen self-assembly have become a major focus of molecular design and synthetic biology. The well-ordered assembly of collagen molecules on mica has attracted extensive attention for its essential applications and studies on the self-assembly process as a model system. Although collagen assembly mediated by various ions on mica has been reported over these years, specific effects of transition metal ions in this field have never been deeply surveyed and discussed till now. In this work, type I collagen extracted from rat tail tendon by pepsin solubilization method was selected to explore the kinetic process and self-assembly characteristics. In the presence of Cu2+ and Zn2+ sulfates, the turbidity method was used to directly measure the kinetic process of collagen self-assembly and atomic force microscopy (AFM) was applied to observe the patterns of collagen self-assembly on mica. The results showed that the favorable properties of transition metal coordination (bonding strength, directionality, and reversibility) were helpful for increasing the collagen fibrillogenesis rate, and at different ion concentrations, Cu2+ and Zn2+ ions affected the interactions between collagen molecules and mica surface by destroying the hydration membranes on the surface of collagen molecules and the hydrogen bonds between the amino acid residues of collagen molecules. Circular dichroism (CD) analysis demonstrated that collagen had complete triple-strand conformation in the presence of Cu2+ and Zn2+. These results and analysis would be helpful for directing the patterns of collagen self-assembly on a solid surface and provide theoretical guidance for creating collagen-based high-performance materials and/or adding functionality in materials for various applications.

CSMC

The rise concern about mobile communication performance has driven the growing demand for the construction of mobile network signal maps which are widely utilized in network monitoring, spectrum management, and indoor/outdoor localization. Existing studies such as time-consuming and labor-intensive site surveys are difficult to maintain an update-to-date finegrained signal map within a large area. The mobile crowdsensing (MCS) paradigm is a promising approach for building signal maps because collecting large-scale MCS data is low-cost and with little extra-efforts. However, the dynamic environment and the mobility of the crowd cause spatio-temporal uncertainty and sparsity of MCS. In this work, we leverage MCS as an opportunity to conduct the city-wide mobile network signal map construction. We propose a fine-grained city-wide Cellular Signal Map Construction (CSMC) framework to address two challenges including (i) the problem of missing and unreliable MCS data; (ii) spatio-temporal uncertainty of signal propagation. In particular, CSMC captures spatio-temporal characteristics of signals from both inter- and intra- cellular base stations and conducts missing signal recovery with Bayesian tensor decomposition to build large-area fine-grained signal maps. Furthermore, CSMC develops a context-aware multi-view fusion network to make full use of external information and enhance signal map construction accuracy. To evaluate the performance of CSMC, we conduct extensive experiments and ablation studies on a large-scale dataset with over 200GB MCS signal records collected from Shanghai. Experimental results demonstrate that our model outperforms state-of-the-art baselines in the accuracy of signal estimation and user localization.

On the possibility of redistribution of loads from the aggregate in silos as a result of seismic impacts

Based on the calculation justification and analysis of experimental data, it is shown that in silos, as in hydraulic structures of cellular construction, as a result of seismic influences, in addition to inertial mass forces and alternating pressures of the filler on the walls, additional pressures associated with an increase in its hanging on the walls and the redistribution of loads that persist for a certain time may arise. The resulting pressures on the walls can be determined according to the author's formula and for a sand aggregate exceed static ones: 1.57 times – lateral, 1.2 times – vertical, associated with the development of friction forces The reason for the occurrence of load redistribution is the development of friction forces at the walls, which occurs as a result of aggregate precipitation during vibration compaction as a result of seismic influences. This phenomenon can be observed in silos, in which large values of dynamic coefficients arise during fluctuations. Calculations supported by experimental data show that under 9-point seismic impacts, the redistribution of loads with an increase in pressure to the above values can be observed along the entire height in silos with sand aggregate up to 25 m high with a diameter of 3m to 6 m, and in silos with a diameter of 8 m – in the upper part to a depth of 13 m. At 8-point seismic impacts, this phenomenon can occur in silos with small diameters of 3m and 4m with an increase in pressure in their upper part with a depth of 3m to 5m, and at 7-point – it covers only the upper part of structures with a depth of 1...1.5 m, that is, practically absent.

Three Dimensional Cellular Automata Sand Castle construction Model Based on Step Factor

It seems that everyone has the experience of making sandcastles on the leisure beach. In order to know how to build a beautiful and sturdy beach castle, this article simulates and analyzes the process of sand castles being eroded by water, and obtains some factors that extend the life of sand castles. First, we model the waves. Simplify the waves into a sine wave. Using calculus and fluid mechanics, the water wave impact force on a particle on the sand castle was calculated. Second, we model the sandcastle. Discretizing time, space, and state, we innovatively introduce the concepts of friction and impact into the model, and propose a new Three-dimensional Cellular Automaton model combined with step factors. We consider each gravel or water molecule as a cell, and simultaneously introduce the moving probability and collision probability to describe the moving trend and collision between the gravel cells, respectively. In order to effectively describe the loss of sand castles in the waves, the gravel cells that are in direct contact with the water cells will receive an impact force calculated by the first model. According to the law of large numbers, we use enough cells to simulate the erosion of sandcastles by the waves. It was found that within a certain range, the farther from the ocean and the more the total gravel, the stronger the anti-erosion ability of the sand castle.

Cellular fluidic-based vascular networks for tissue engineering

• Constructing vascularized networks is critical to artificial tissues and organs. • “Cellular fluidics” is a novel concept of deterministic fluid control based on well-designed unit cells. • The cellular fluidic platform is promising for building vascular networks in tissue engineering. Artificial organs are devices implanted into the living body as a substitute for damaged or diseased organs. Current efforts focus on the construction of fully functionalized artificial tissues/organs with vascular networks. Although engineering efforts have been made in creating artificial vessels with simple or complex configurations, building vascular networks with hierarchical architectures approximating native counterparts remains challenging. Herein, we give a perspective of cellular fluidics-based construction of vascular networks for tissue engineering, with inspirations drawn from a novel concept of 3D fluidic control platform based on unit-cell constructs. Through architected design of the unit cells, it enables programmed control over gas-liquid-solid interfaces and fluid flow processes in open-cell structures. This cellular-fluidics concept and the associated platform provide lots of inspirations for constructing artificial vascular networks. We believe that cellular fluidics opens a new avenue for fluid control and deterministic delivery, and would find vast opportunities in tissue engineering.

A Highly Heterogeneous Mutational Pattern in POEMS Syndrome

Background: POEMS syndrome is a rare plasma cell dyscrasia. Despite the presence of monoclonal protein, POEMS syndrome patients commonly have less than 5% monoclonal plasma cells in the bone marrow. Only one study has reported the genetic and transcriptional features of bone marrow plasma cells, and the underlying role of aberrant plasma cells is not well understood. Herein, in the current study, we aimed to characterize the genetic profile of bone marrow CD138-positive cells from Chinese patients with newly diagnosed POEMS syndrome. Methods: Forty-two patients with newly diagnosed POEMS syndrome based on the International Myeloma Working Group criteria at our institute were included in our study. Twenty milliliters of bone marrow aspirates was obtained and sorted by magnetic microbeads conjugated to monoclonal human anti-CD138 antibodies. The mutational features of these bone marrow plasma cells were analyzed using a two-step strategy. DNA of the bone marrow plasma cells from ten patients was first sequenced by whole exome sequencing to find significantly mutated genes and mutated driver genes, with paired peripheral blood mononuclear cells as a control. Bone marrow plasma cells of an additional thirty-two patients were then analyzed by target region sequencing to validate the mutations. Results: Whole exome sequencing of 10 newly diagnosed patients showed a total of 170 somatic mutations in exonic regions and splicing sites. Three significantly mutated genes-LILRB1 (10%), HEATR9 (20%), and FMNL2 (10%)-and eight mutated known driver genes (MYD88, NFKB2, CHD4, SH2B3, POLE, STAT3, CHD3, CUX1) were identified in five patients. The mutation spectrum of WES revealed C > T/G > A as the most common mutation type, while the mutation signature was not the same as known signatures reported in various cancer types. For significant pathway and gene ontology analysis, 69 genes with possibly pathogenic nonsynonymous mutations were selected. Mutated genes were enriched in pathways including "chromatin organization", "chromatin modifying enzymes", and "apoptosis", and terms such as "cellular anatomical entity", "regulatory region nucleic acid binding" and "centrosome" that are used to describe cellular structure construction. To evaluate the mutation prevalence of genes identified in WES, we performed target region sequencing of 77 candidate genes in 32 other patients. The candidate gene list consisted of significantly mutated genes and known driver genes identified in WES, recurrently mutated genes previously detected in POEMS syndrome, the VEGF gene, and genes of light-chain amyloidosis, multiple myeloma, hematopoietic disease or lymphoid neoplasm in the public databases. As a result, a total of 32 mutated genes were identified in 28 of 32 patients. Genes recurrently mutated in more than three patients included CUX1 (19%), DNAH5 (16%), USH2A (16%), KMT2D (16%), and RYR1 (12%). Driver genes of multiple myeloma (BIRC3, LRP1B, KDM6A, ATM) and eleven genes reported in light-chain amyloidosis were also identified in target region sequencing. Notably, VEGFA mutations were detected in one patient. Conclusions: Heterogeneous genomic profiles of bone marrow plasma cells in POEMS syndrome were revealed in our study. The mutational landscape of POEMS syndrome might share some similarity to that of other plasma cell diseases. Disclosures No relevant conflicts of interest to declare.

The Necessity to Assess the Electromagnetic Environment Near 5-G Radio-Emitting Objects with Instrumental Procedure

The features of the new 5G standard if compared to the currently used 4G lie within a significant frequency range expansion, and the implementation of the Internet of things. They made it impossible to expand the existing safety standard of broadband cellular network construction in large cities to the new standard. Differences between the Western and Russian approaches to the maximum permissible power level assessment and the lack of publications on the subject prompt measurement experiments in order to obtain an approximate electromagnetic environment assess near radio-emitting objects. At the preliminary stage of the measurements, it is necessary to choose the right measuring instruments and procedures, since the choice determines the price-quality relationship of the experiment. In the paper the results of the analysis for the known measuring instruments are given with an account to the special requirements formulated according to 5G standard features. The conclusion on the availability of the measuring instruments with the required characteristics is made. It is shown that the experiment efficiency depends on the measurement area dimensions and the measurement points spacing. In case of reflector antenna of 0.9 m diameter operating at 6 GHz the number of measurement points can be reduced without a loss of accuracy if the measured antenna passport data as well as the recommendations given in the paper are taken into an account.

Bosonic crystalline symmetry protected topological phases beyond the group cohomology proposal

It is demonstrated by explicit construction that three-dimensional bosonic crystalline symmetry protected topological (cSPT) phases are classified by $H_{\phi}^{5}(G;\mathbb{Z})\oplus H_{\phi}^{1}(G;\mathbb{Z})$ for all 230 space groups $G$, where $H^n_\phi(G;\mathbb{Z})$ denotes the $n$th twisted group cohomology of $G$ with $\mathbb{Z}$ coefficients, and $\phi$ indicates that $g\in G$ acts non-trivially on coefficients by sending them to their inverses if $g$ reverses spacetime orientation and acts trivially otherwise. The previously known summand $H_{\phi}^{5}(G;\mathbb{Z})$ corresponds only to crystalline phases built without the $E_8$ state or its multiples on 2-cells of space. It is the crystalline analogue of the "group cohomology proposal" for classifying bosonic symmetry protected topological (SPT) phases, which takes the form $H_{\phi}^{d+2}(G;\mathbb{Z})\cong H_{\phi}^{d+1}(G;U(1))$ for finite internal symmetry groups in $d$ spatial dimensions. The new summand $H_{\phi}^{1}(G;\mathbb{Z})$ classifies possible configurations of $E_8$ states on 2-cells that can be used to build crystalline phases beyond the group cohomology proposal. The completeness of our classification and the physical meaning of $H_{\phi}^{1}(G;\mathbb{Z})$ are established through a combination of dimensional reduction, surface topological order, and explicit cellular construction. The value of $H_{\phi}^{1}(G;\mathbb{Z})$ can be easily read off from the international symbol for $G$. Our classification agrees with the prediction of the "generalized cohomology hypothesis," which concerns the general structure of the classification of SPT phases, and therefore provides strong evidence for the validity of the said hypothesis in the realm of crystalline symmetries.

Spatial analysis for calculating closest distance of operators’ location to Base Transceiver Station (BTS) in Banda Aceh city

Base Transceiver Station (BTS) is used to generate auxiliary signal for cellular uses. BTS will support all the activities regarding data exchange such as messaging and web browsing. The spatial data plays important role to support BTS’s signal coverage area. The spatial data also can be used for designing of new cellular networks and construction new BTS. This research purpose is to help operator manager find the distance of BTS distribution that will be used to make group of BTS position for the operators. In this research Geographic Information Systems (GIS) has been utilized to analyse the nearest distance and to create group of BTS. Spatial network analyst uses network data path to find out the nearest distance from operators’ location to all of BTS in Banda Aceh by using tools closest facility, and to analyse the operators’ location grouping based on the mean value BTS distance by using buffer method. The result of this research has calculated the average distance from the operators’ location to all BTS is 6.2 Kilometres. Based on the average distance the first team will manage 7 BTS and the second team will manage 14 BTS.

Quantitative 3D structural analysis of the cellular microstructure of sea urchin spines (I): Methodology

The mineralized skeletons of echinoderms are characterized by their complex, open-cell porous microstructure (also known as stereom), which exhibits vast variations in pore sizes, branch morphology, and three-dimensional (3D) organization patterns among different species. Quantitative description and analysis of these cellular structures in 3D are needed in order to understand their mechanical properties and underlying design strategies. In this paper series, we present a framework for analyzing such structures based on high-resolution 3D tomography data and utilize this framework to investigate the structural designs of stereom by using the spines from the sea urchin Heterocentrotus mamillatus as a model system. The first paper here reports the proposed cellular network analysis framework, which consists of five major steps: synchrotron-based tomography and hierarchical convolutional neural network-based reconstruction, machine learning-based segmentation, cellular network registration, feature extraction, and data representation and analysis. This framework enables the characterization of the porous stereom structures at the individual node and branch level (~10 µm), the local cellular level (~100 µm), and the global network level (~1 mm). We define and quantify multiple structural descriptors at each level, such as node connectivity, branch length and orientation, branch profile, ring structure, etc., which allows us to investigate the cellular network construction of H. mamillatus spines quantitatively. The methodology reported here could be tailored to analyze other natural or engineering open-cell porous materials for a comprehensive multiscale network representation and mechanical analysis. Statement of SignificanceThe mechanical robustness of the biomineralized porous structures in sea urchin spines has long been recognized. However, quantitative cellular network representation and analysis of this class of natural cellular solids are still limited in the literature. This constrains our capability to fully understand the mechanical properties and design strategies in sea urchin spines and other similar echinoderms’ porous skeletal structures. Combining high-resolution tomography and computer vision-based analysis, this work presents a multiscale 3D network analysis framework, which allows for extraction, registration, and quantification of sea urchin spines’ complex porous structure from the individual branch and node level to the global network level. This 3D structural analysis is relevant to a diversity of research fields, such as biomineralization, skeletal biology, biomimetics, material science, etc.

Molecular Aspects of Adipose-Derived Stromal Cell Senescence in a Long-Term Culture: A Potential Role of Inflammatory Pathways

Long-term culture of mesenchymal stromal/stem cells in vitro leads to their senescence. It is very important to define the maximal passage to which the mesenchymal stromal/stem cells maintain their regenerative properties and can be used for cellular therapies and construction of neo-organs for clinical application. Adipose-derived stromal/stem cells were isolated from porcine adipose tissue. Immunophenotype, population doubling time, viability using bromodeoxyuridine assay, MTT assay, clonogencity, β-galactosidase activity, specific senescence-associated gene expression, apoptosis, and cell cycle of adipose-derived mesenchymal stromal/stem cells (AD-MSCs) were analyzed. All analyses were performed through 12 passages (P). Decreasing viability and proliferative potential of AD-MSCs with subsequent passages together with prolonged population doubling time were observed. Expression of β-galactosidase gradually increased after P6. Differentiation potential of AD-MSCs into adipogenic, chondrogenic, and osteogenic lineages decreased at the end of culture (P10). No changes in the cell cycle, the number of apoptotic cells and expression of specific AD-MSC markers during the long-term culture were revealed. Molecular analysis showed increased expression of genes involved in activation of inflammatory response. AD-MSCs can be cultured for in vivo applications without loss of their properties up to P6.