Bridge Formation Research Articles

Preparation of Chitosan Oleogel from Capillary Suspension and Its Application in Pork Meatballs

In the oil dispersion of chitosan, the formation of a capillary bridge was triggered by adding a small amount of water to obtain an oleogel. With this method, the types of liquid oil and the ratio of oil/chitosan/water were explored to achieve an optimal oleogel. MCT performed best, followed by soybean oil, which was chosen for its edibility and cost. Increasing chitosan from 15% to 45% reduced oil loss from 46% to 13%, and raising the water/chitosan ratio from 0 to 0.8 lowered oil loss from 37% to 13%. After normalization, the optimal soybean oil, chitosan, and water ratio was 1:0.45:0.36, yielding a solid-like appearance, minimal oil loss of 13%, and maximum gel strength and viscosity. To assess the potential application of the optimized oleogel, it was incorporated into pork meatballs as a replacement for pork fat. Textural and cooking experiments revealed that as the oleogel content increased, the hardness of the pork meatballs increased, while the cooking loss decreased. It suggested that the chitosan oleogel could enhance the quality of pork meatballs while also contributing to a healthier product by reducing saturated fat content.

Structural basis of the allosteric regulation of cyanobacterial glucose-6-phosphate dehydrogenase by the redox sensor OpcA

The oxidative pentose phosphate (OPP) pathway is a fundamental carbon catabolic route for generating reducing power and metabolic intermediates for biosynthetic processes. In addition, its first two reactions form the OPP shunt, which replenishes the Calvin-Benson cycle under certain conditions. Glucose-6-phosphate dehydrogenase (G6PDH) catalyzes the first and rate-limiting reaction of this metabolic route. In photosynthetic organisms, G6PDH is redox-regulated to allow fine-tuning and to prevent futile cycles while carbon is being fixed. In cyanobacteria, regulation of G6PDH requires the redox protein OpcA, but the underlying molecular mechanisms behind this allosteric activation remain elusive. Here, we used enzymatic assays and in vivo interaction analyses to show that OpcA binds G6PDH under different environmental conditions. However, complex formation enhances G6PDH activity when OpcA is oxidized and inhibits it when OpcA is reduced. To understand the molecular basis of this regulation, we used cryogenic electron microscopy to determine the structure of Synechocystis G6PDH and the G6PDH-OpcA complex. OpcA binds the G6PDH tetramer and induces conformational changes in the active site of G6PDH. The redox sensitivity of OpcA is achieved by intramolecular disulfide bridge formation, which influences the allosteric regulation of G6PDH. In vitro assays reveal that the level of G6PDH activation depends on the number of bound OpcA molecules, which implies that this mechanism allows delicate fine-tuning. Our findings unveil a unique molecular mechanism governing the regulation of the OPP in Synechocystis.

Annexin- and calcium-regulated priming of legume root cells for endosymbiotic infection

Legumes establish endosymbioses with arbuscular mycorrhizal (AM) fungi or rhizobia bacteria to improve mineral nutrition. Symbionts are hosted in privileged habitats, root cortex (for AM fungi) or nodules (for rhizobia) for efficient nutrient exchange. To reach these habitats, plants form cytoplasmic cell bridges, key to predicting and guiding fungal hyphae or rhizobia-filled infection thread (IT) root entry. However, the underlying mechanisms are poorly studied. Here we show that unique ultrastructural changes and calcium (Ca2+) spiking signatures, closely associated with Medicago truncatula Annexin 1 (MtAnn1) accumulation, accompany rhizobia-related bridge formation. Loss of MtAnn1 function in M. truncatula affects Ca2+ spike amplitude, cytoplasmic configuration and rhizobia infection efficiency, consistent with a role of MtAnn1 in regulating infection priming. MtAnn1, which evolved in species establishing intracellular symbioses, is also AM-symbiosis-induced and required for proper arbuscule formation. Together, we propose that MtAnn1 is part of an ancient Ca2+-regulatory module for transcellular endosymbiotic infection.

Preparation, oil removal and flocculation efficiency evaluation of a PAC-P(AM-BA) hybrid polymer flocculant based on response surface method

In this study, a novel inorganic-organic hybrid polymer flocculant PAC-P(AM-BA) with hydrophobic groups was synthesized using the aqueous solution free radical micelle polymerization method. The raw materials used were polyaluminum chloride (PAC), polyacrylamide (AM), and butadiene acetate (BA). Experimental results demonstrated that the optimal preparation conditions for PAC-P(AM-BA) were as follows: initiator mass fraction of 0.15% (based on total monomer), n(AM):n(BA)=98:2, urea mass fraction of 3.00%, total monomer mass fraction of 15.597%, inorganic component (PAC) mass fraction of 1.346%, and polymerization temperature of 24.225℃. In PAC-P(AM-BA), BA was chemically bonded within PAM, while PAC was connected to the organic long chain through ion bonding. Moreover, the thermal decomposition temperature of PAC-P(AM-BA) was found to be 275.93℃. The hybrid flocculant exhibited a rough surface and displayed strong adsorption bridge formation as well as net capture and sweeping performance.

Synthesis and Structural Characterization of 2,2’-Bipyridine Zinc Formate: Analysis of Formate Bonding and Hydrosilylation of CO2 and Carbonyl Compounds

The zinc formate compound (bipy)Zn(O2CH)2 is obtained via the reaction of Zn(O2CH)2 with 2,2’-bipyridine (bipy). In addition, (bipy)Zn(O2CH)2 may be formed from zinc hydride via addition of bipy followed by addition of (i) HCO2H and (ii) CO2. The molecular structure of (bipy)Zn(O2CH)2 has been determined by X-ray diffraction, thereby demonstrating that it exists as a monomeric species with a distorted tetrahedral zinc center and κ1-monodentate formate ligands. As such, the coordination environment of the zinc provides a contrast to the octahedral sites in the isomeric 4,4’-bipyridine counterpart, (bipy4,4’)Zn(O2CH)2, and the aqua derivative, (bipy)Zn(O2CH)2(OH2)•H2O, both of which feature bridging formate ligands. Analysis of the bonding within the formate ligand indicates that the zinc–formate moiety is not best represented by a Zn–O–C(=O)H resonance structure, but instead possesses a significant ionic component that reduces the C=O bond order and increases the C–O bond order. The formate compound (bipy)Zn(O2CH)2 participates in hydrosilylation transformations involving CO2 and carbonyl compounds, including (i) the reaction of CO2 with (MeO)3SiH to afford HCO2Si(OMe)3 and (ii) insertion of Ph2CO, PhC(O)Me, Me2CO and PhCHO into the Si–H bonds of PhSiH3 to afford PhSi[OCH(R)R’]3via PhSiH2[OCH(R)R’] and PhSiH[OCH(R)R’]2.

Convergent evolution of berberine biosynthesis.

Berberine is an effective antimicrobial and antidiabetic alkaloid, primarily extracted from divergent botanical lineages, specifically Coptis (Ranunculales, early-diverging eudicot) and Phellodendron (Sapindales, core eudicot). In comparison with its known pathway in Coptis species, its biosynthesis in Phellodendron species remains elusive. Using chromosome-level genome assembly, coexpression matrix, and biochemical assays, we identified six key steps in berberine biosynthesis from Phellodendron amurense, including methylation, hydroxylation, and berberine bridge formation. Notably, we discovered a specific class of O-methyltransferases (NOMT) responsible for N-methylation. Structural analysis and mutagenesis of PaNOMT9 revealed its unique substrate-binding conformation. In addition, unlike the classical FAD-dependent berberine bridge formation in Ranunculales, Phellodendron uses a NAD(P)H-dependent monooxygenase (PaCYP71BG29) for berberine bridge formation, originating from the neofunctionalization of tryptamine 5-hydroxylase. Together, these findings reveal the convergence of berberine biosynthesis between Coptis and Phellodendron and signify the role of the convergent evolution in plant specialized metabolisms.

Comparing effectiveness of mineral trioxide aggregate, bioceramic putty and tannic acid in maintaining pulp vitality after experimental pulpotomy in rats

This study aimed to evaluate and compare the effectiveness of mineral trioxide aggregate (MTA), bioceramic putty (BP) and tannic acid (TA) for experimental pulpotomy. Our in-vivo experimental study involved sample of 45 rats that were randomly divided into 4 groups: Group 1 (subdivided into negative (1-A) and positive (1-B) subgroups), Group 2 (MTA treated), Group 3 (BP treated) and Group 4 (TA treated). 4 weeks post pulpotomy, specimens were analyzed histologically, immunohistochemically using dentin sialoprotein marker, and histomorphometrically by assessing the thickness of newly formed dentin bridge. Group 1-B showed pulp necrosis without hard tissue formation. Group 2 showed moderate dentin formation while group 3 presented a thick layer of calcific barrier. Group 4 showed dentin bridge formation, however, irregular pulp calcifications and radicular pulp necrosis were seen. The thickness of newly formed dentin bridge showed a significant difference between group 1-B and group 2, 3 &4. Significant difference was found between group 2&3 and group 3&4. Dentin sialoprotein immunohistochemical expression was negative in group 1-B, mild in group 2, strong in group 3 and moderate in group 4. MTA and BP proved to be effective pulpotomy agents with BP being superior. For TA, further studies are required to explain the recorded unfavorable effects in some specimens.

Effect of Salt Bridge Formation on Proton Transport in CNTs

Various sectors have initiated technology development projects aimed at realizing a hydrogen-based society with low carbon dioxide (CO2) emissions. A proton (H+) transfer system with high permeability and selectivity is essential for the hydrogen infrastructure and fuel cells that support a hydrogen-based society. Therefore, intensive research is underway to design bioinspired artificial proton channels. Natural proteins achieve high proton selectivity by organizing proton-conducting pathways with scattered ionizable side chains and controlling proton transport through Vehicle and Grotthuss mechanisms. The Hv1 channel is a proton-selective protein that contains the amino acids aspartic acid (Asp) and arginine (Arg) in its pathway. As shown in Figure 1, the proton transport mechanism of Hv1 channels is suggested that Asp and Arg can be protonated, allowing them to transport protons via the Grotthuss mechanism. Additionally, Asp and Arg form salt bridges to close the pathway, thereby inhibiting the transport of other ions via the vehicle mechanism. However, the relationship between Asp and Arg and their impact on the transport mechanism remains unclear. It is important to elucidate the relationship between the inhibition of transport and pore size, as well as to understand the correlation between the inhibition of transport and salt bridges, to install proton transport mechanism of Hv1 channels into artificial proton channels. In this study, carbon nanotubes (CNTs) were used as a model pore for artificial ion channels, and we analyzed the effects different sizes of CNTs modifying with Asp and Arg on ion transport properties using molecular dynamics simulations.We adopted the armchair CNTs model shown in Table 1, using the CNTs chirality (5,5), which is known to spontaneously fill with water at room temperature, as the smallest model. For the molecular models of Asp and Arg, side chain models of Asp(N)–Arg(N) and Asp(-)– Arg(+) pairs, which can form salt bridges, were modified inside CNTs.The results of the probability of hydrogen bond formation are shown in Figure 2. The results confirm that hydrogen bonds are always maintained at a pore radius R = 4.75 Å (CNTs chirality = 7,7) for both conditions. As the distance between Asp and Arg increases with increasing pore radius R above R = 4.75 Å, it appears that the hydrogen bonds cannot be maintained. Even when the pore radius is smaller than R = 4.75 Å, the probability of hydrogen bonding formation decreases. In the poster, we will present further structural analyses, such as the orientations of Asp and Arg and their relation to the hydronium ion conformation.[1] Dudev, T., Musset, B., Morgan, D. et al. Selectivity Mechanism of the Voltage-gated Proton Channel, HV1. Sci Rep 5, 10320 (2015). Figure 1

Recombinant human FOXJ1 protein binds DNA, forms higher-order oligomers, has gel-shifting domains and contains intrinsically disordered regions

Forkhead box protein J1 (FOXJ1) is the key transcriptional regulator during the conversion of mammalian primary cilium with a 9 + 0 architecture to the motile (9 + 2) one. The nucleotide sequences of the full-length and DNA-binding domain (DBD) of the open reading frame (ORF) were isolated and expressed into E. coli as 6xHis-tagged proteins. Upon induction, the DBD formed inclusion bodies that solubilized with 8 M urea. No induction of 6xHis-FOXJ1 protein was seen despite sub-cloning into several expression vectors and E. coli host strains. To improve induction and solubility, the 6xHis tag was substituted with Glutathione S-transferase (GST), and weak induction was seen in E. coli BL21(DE3). The GST-FOXJ1 showed anomalous migration on denaturing gel electrophoresis (AM-DRE), migrating at approximately 83 kDa instead of its calculated molecular weight (Mr) of 72.4 kDa. It was also unstable and led to degradation products. The 6xHis tag was substituted with Glutathione S-transferase (GST) to improve induction and solubility. Codon-optimization improved the induction, but the protein still showed AM-DRE and instability. It seemed that the recombinant protein was either toxic or posed a metabolic burden to the E. coli cells or, once produced was prone to degradation due mainly to the lack of post-translational modification (PTM). This process is required for some eukaryotic proteins after they are manufactured in the ribosomal factory. Both the purified recombinant proteins exhibited cysteine-induced oligomerization via the formation of disulphide bridges since this was reduced using dithiothreitol (DTT). Both were equally functional as these individually bound to an oligonucleotide, a consensus DNA-binding sequence for FOX proteins. Further, the recombinant polypeptides corresponding to the C-terminus and N-terminus show anomalies indicating that the highly acidic residues (known as polyacidic gel-shifting domains) in these polypeptides contribute to the AM-DRE. We demonstrate for the first time that the recombinant HsFOXJ1 and its DBD bind to DNA, its polyacidic gel-shifting domains are the reason for the AM-DRE, is unstable leading to degradation products, exhibits cysteine-induced oligomerization and harbours intrinsically disordered regions.

Methane Gas Transport in Ca-MMT Shale Nanoslits Considering Water Content Effects: Insights from Molecular Dynamics Simulations.

Two-phase flow remains a significant challenge in the development of water-bearing shale gas, particularly regarding the flow of gases through clay minerals in such formations. Nonequilibrium molecular dynamics simulation is investigated to research the two-phase flow of water (H2O) and methane (CH4) through Ca-montmorillonite (MMT) shale nanoslits. The results indicate that water molecules preferentially adsorb onto the surfaces of the Ca-MMT shale nanoslits, leading to the formation of water bridges within the nanoslits as water content increases. Notably, CH4 molecules exhibit complete solubility in the water phase, and their maximum velocity gradually decreases, resulting in a flattened parabolic flow profile with a higher gas-water percent (GWP). In the two-phase flow, CH4 continues to flow without slip in the inorganic nanopores due to water molecules occupying the surfaces and creating a water film. However, when the water content (GWP) exceeds 80.87%, CH4 gas molecules become dissolved in the water, filling the inorganic nanoslits and leading to a zero-gas flux. This condition causes CH4 retention in adjacent nanoslits, creating a "water lock gas" effect. This research provides a theoretical foundation for understanding multiphase flow in water-bearing shale gas and offers a refined description of the shale gas extraction process for future application.

POLITENESS STRATEGIES IN WEDNESDAY ADDAMS’ UTTERANCES: MAINTAINING SELF-IMAGE AND OTHERS’ AMIDST REJECTION

Communication is a form of bridge to convey thoughts between one individual and another. Every person must have their measure of being polite and harmonious according to who they are dealing with, including Wednesday Addams. This pragmatic research scrutinizes the politeness strategies employed by Wednesday Addams, the lead female protagonist in the Netflix series Wednesday. The character Wednesday Addams utilizes politeness strategies to maintain public and self-image during interactions while solving a murder case. Using descriptive qualitative methods, the researchers found that Wednesday frequently used bald on-record strategies with straightforward speech without being threatening. In contrast, off-record strategies were used less frequently. The researchers also observed that Wednesday used all the politeness strategies outlined by Brown and Levinson (1987). This study highlights the significance of politeness, not only for interpersonal relationships but also for achieving long-term goals, as demonstrated in the “Wednesday” series. However, further studies could provide additional perspectives and challenge the findings presented in this study.

The effect of surface chemistry on the caking behaviour of sucrose crystals

The caking behaviour of organic crystals presents a significant challenge in both the food and pharmaceutical industries. This study aimed to investigate how surface impurities influence the caking behaviour of sucrose (sugar) crystals. Sucrose crystals were selected as the model material due to their relevance in various industries such as food processing and pharmaceuticals. The impact of surface chemistry was assessed for sucrose crystals with varying levels of impurities, namely white sugar, light brown sugar, and dark brown sugar. These crystals were subjected to controlled cycles of humidity exposure, compaction, and drying to induce caking, simulating real-world scenarios. The caking propensity was evaluated using a compression test, while the surface chemistry was characterized through Inverse Gas Chromatography (IGC). Moisture sorption properties were evaluated using a Dynamic Vapor Sorption (DVS) technique, and the formation of solid bridges was studied using scanning electron microscopy (SEM) and X-ray computed tomography (XCT). The results indicate that impurities play a crucial role in enhancing the caking behaviour of sucrose crystals by influencing their hygroscopicity and facilitating solid bridge formation. This study provides valuable insights into the relationship between surface chemistry, moisture sorption properties, and the caking behaviour of sucrose crystals, offering strategies to mitigate caking issues.

H2O2-mediated cell wall remodeling and pectin demethylesterification are involved in maintaining postharvest texture of table grape by sulfur dioxide

Berry texture affects consumer acceptance and postharvest shelf life of table grapes. This study elucidates how sulfur dioxide (SO2) treatment maintains grape texture quality, focusing on the role of hydrogen peroxide (H2O2)-mediated cell wall modifications. SO2 treatment exhibited effects similar to those of H2O2 treatment, resulting in firmer berries with more intact cell wall structures, higher contents of chelate-soluble pectin, sodium carbonate-soluble pectin, hemicellulose, and cellulose, with lower levels of water-soluble pectin compared to untreated fruit. Moreover, it delays pectin nanostructure disassembly and reduces degree of pectin methylesterification, which facilitates the formation of calcium bridges between demethylesterified pectin and increased calcium ions, thereby strengthening the cell wall and weakening enzymatic pectin degradation. Conversely, combining ROS generation inhibitors with SO2 mitigated these effects. Overall, these findings highlight the role of H2O2-mediated cell wall modification in maintaining grape postharvest texture through SO2 treatment, providing new insights for managing grape postharvest softening.

Tetracyanoethylene as a Building Block in the π-Expansion of 1,4-Dihydropyrrolo[3,2-b]pyrroles.

The outcome of the reaction of tetracyanoethylene with 1,4-dihydropyrrolo[3,2-b]pyrroles (DHPPs) strongly depends on the character of the substituents present at positions 2 and 5. With electron-withdrawing substituents, the reaction does not occur at all, while, in contrast, the presence of electron-donating substituents yields addition-elimination products. When thiazol-2-yl substituents are located at positions 2 and 5, addition occurs at the thiazole ring, rather than of the DHPP core. In cases where very electron-rich heterocycles are present at positions 2 and 5, a second addition occurs followed by aromatization, leading to the formation of an additional benzene ring bridging two heterocyclic scaffolds. The reaction occurs only at one site since the presence of the strongly electron-withdrawing tricyanoethylene group has a profound impact on electron density at the remaining free position 6. The DHPPs possessing a tricyanoethylene group are strongly polarized and thus enable a push-pull system showing red-shifted absorption and negligible fluorescence. In contrast, dyes possessing a 1,2-dicyanobenzene moiety exhibit strong emission bathochromically shifted by over 100 nm compared to parent 1,4-dihydrotetraarylpyrroles[3,2-b]pyrroles (TAPPs). Computational studies shed light on the evolution of the photophysical properties as a function of the substitution pattern of the final systems.

Boosting the Formation of Brønsted Acids on Flame-made WOx/ZrO2 for Glucose Conversion.

WOx/ZrO2with ahigher concentrationof Brønsted acid sites (BAS) and a bigger ratio of Brønsted to Lewis acid sites (B/L) than achievable by conventional impregnation (IM)were synthesized usingflame spray pyrolysis (FSP). The rapid quenching and short residence time inherent to FSP prevent the accumulation of W atoms on the ZrO2 support and thus provide an excellent surface dispersion of WOx species. As a result, FSP-made WOx/ZrO2 (FSP-WOx/ZrO2) has a much higher surface concentration of three-dimensional Zr-WOx clusters than corresponding materials prepared by conventional impregnation (IM-WOx/ZrO2). The coordination of W-OH to the unsaturated Zr4+ sites in these clusters results in a remarkable decrease of the concentration of Lewis acid sites (LAS) on the surface of ZrO2 and promotes the formation of bridging W-O(H)-Zr hydroxyl groups acting as BAS. FSP-WOx/ZrO2 possesses ~80% of BAS and a B/L ratio of around 4, while IM-WOx/ZrO2 exhibits ~50% BAS and a B/L ratio of around 1. These catalysts were evaluated in the dehydration of glucose to HMF. The catalytic study demonstrated that B/L ratio plays a crucial role in glucose conversion. The best catalyst, FSP-WOx/ZrO2 with a W/Zr ratio of 1/10 affords nearly 100% glucose conversion and an HMF selectivity of 56-69%.

Incorporating Microbial Stimuli for Osteogenesis in a Rabbit Posterolateral Spinal Fusion Model.

Autologous bone grafts are commonly used to repair defects in skeletal tissue, however, due to their limited supply there is a clinical need for alternatives. Synthetic ceramics present a promising option but currently lack biological activity to stimulate bone regeneration. One potential approach to address this limitation is the incorporation of immunomodulatory agents. In this study, we investigate the application of microbial stimuli to stimulate bone formation. Three different microbial stimuli were incorporated in a biphasic calcium phosphate (BCP) ceramic: Bacille Calmette-Guérin (BCG), gamma-irradiated Staphylococcus aureus (γi-S. aureus), or γi-Candida albicans (γi-C. Albicans). The constructs were then implanted in both a rabbit posterolateral spinal fusion (PLF) and an intramuscular implant model for 10 weeks and compared to a nonstimulated control construct. For the PLF model, the formation of a bony bridge was evaluated by manual palpation, micro computed tomography, and histology. While complete fusion was not observed, the BCG condition was most promising with higher manual stiffness and almost twice as much bone volume in the central fusion mass compared to the control (9 ± 4.4% bone area vs. 4.6 ± 2.3%, respectively). Conversely, the γi-S. aureus or γi-C. albicans appeared to inhibit bone formation (1.4 ± 1.4% and 1.2 ± 0.6% bone area). Bone induction was not observed in any of the intramuscular implants. This study indicates that incorporating immunomodulatory agents in ceramic bone substitutes can affect bone formation, which can be positive when selected carefully. The readily available and clinically approved BCG showed promising results, which warrants further research for clinical translation.

Fe2O3/In2O3 composite materials for dual-selective detection of H2S and NO2: Study on sensing mechanisms and sensing transition

Developing concise and efficient dual-selective gas sensors has been a significant challenge in sensing technology. In this study, a Fe2O3/In2O3 (FIO) composite material was successfully synthesized via a water bath method for highly efficient dual-selective detection of H2S and NO2. The enhanced dual-selectivity of the composite material is attributed to the high-quality heterojunction formed at the Fe2O3 and In2O3 interface, which provides more active sites and optimizes the electronic structure, thereby greatly improving electron transport efficiency. Consequently, this unique structure significantly enhances the gas sensing response and stability of the composite material. The optimal FIO-3 composite shows significant responses: 14.7 at 80 °C with 100 ppm H2S and 64.3 at 100 °C with 700 ppb NO2, achieving 7- and 31-fold improvements over pure Fe2O3. Analysis indicates that the dual-selective response of the FIO composite material is attributed to synergistic enhancement mechanisms, primarily controlled by high-temperature activation effects. Further density functional theory (DFT) studies reveal changes in charge density at the composite material interface, particularly facilitated by the formation of oxygen bridges promoting electron transfer from In2O3 to Fe2O3. This study offers new insights into the sensing transition of dual-selective gas sensors.

Calcium phosphate complex of recombinant human thrombomodulin promote bone formation in interbody fusion.

Interbody fusion is an orthopedic surgical procedure to connect two adjacent vertebrae in patients suffering from spinal disc disease. The combination of synthetic bone grafts with protein-based drugs is an intriguing approach to stimulate interbody bone growth, specifically in patients exhibiting restricted bone progression. Recombinant human thrombomodulin (rhTM), a novel protein drug characterized by its superior stability and potency, shows promise in enhancing bone formation. A composite bone graft, termed CaP-rhTM, has been synthesized, combining calcium phosphate (CaP) microparticles as a delivery vehicle for rhTM to facilitate interbody fusion.In vitrostudies have demonstrated that rhTM significantly promotes the proliferation and maturation of preosteoblasts at nanogram dosage, while exerting minimal impact on osteosarcoma cell growth. The expression levels of mature osteoblast markers, including osteocalcin, osteopontin, alkaline phosphatase, and calcium deposition were also enhanced by rhTM. In rat caudal disc model of interbody fusion, CaP-rhTM with 800 ng of drug dosage was implanted along with a polylactic acid cage, to ensure structural stability within the intervertebral space. Microcomputed tomography analyses revealed that from 8 to 24 weeks, CaP-rhTM substantially improves both bone volume and trabecular architecture, in addition to the textural integrity of bony endplate surfaces. Histological examination confirmed the formation of a continuous bone bridge connecting adjacent vertebrae. Furthermore, biomechanical assessment via three-point bending tests indicated an improved bone quality of the fused disc. This study has demostrated that rhTM exhibits considerable potential in promoting osteogenesis. The use of CaP-rhTM has also shown significant improvements in promoting interbody fusion.

Cold Consolidation of Pharmaceutical Waste Glass Powders Through Alkali Activation and Binder Jet 3D Printing.

The recent COVID-19 emergency has led to an impressive increase in the production of pharmaceutical vials. This has led to a parallel increase in the amounts of waste glass; manufacturers typically recover material from faulty containers by crushing, giving origin to an unrecyclable fraction. Coarse fragments are effectively reused as feedstock for glass melting; on the contrary, fine powders (<100 microns), contaminated by metal and ceramic particles due to the same crushing operations, are landfilled. Landfilling is also suggested for pharmaceutical containers after medical use. This study aims at proposing new opportunities for the recycling of fine glass particles, according to recent findings concerning alkali activation of pharmaceutical glass, combined with novel processing, i.e., binder jetting printing. It has already been shown that pharmaceutical glass, immersed in low-molarity alkaline solution (not exceeding 2.5 M NaOH), undergoes surface dissolution and hydration; cold consolidation is later achieved, upon drying at 40-60 °C, by a condensation reaction occurring at hydrated layers of adjacent particles. Binder jetting printing does not realize a full liquid immersion of the glass powders, as the attacking solution is selectively sprayed on a powder bed. Here, we discuss the tuning of key parameters, such as the molarity of the attacking solution (from 2.5 to 10 M) and the granulometry of the waste glass, to obtain stable printed blocks. In particular, the stability depends on the formation of bridges between adjacent particles consisting of strong T-O bonds (Si-O-Si, Al-O-Si, B-O-Si), while degradation products (concentrating Na ions) remain as a secondary phase, solubilized by immersion in boiling water. Such stability is achieved by operating at 5 M NaOH.

CCR7 depletion alleviates bony growth imbalance following physeal injury in mice

Growth plates are the frequent sites of skeletal injury in children, leading to skeletal growth imbalances. Chemokines, including the receptor CCR7, play a crucial role in stem cell recruitment and cartilage homeostasis, with previous studies linking CCR7 to osteoarthritis progression. However, its role in growth plate cartilage remains unclear. We analyzed the role of CCR7 in the physeal cartilage repair process in mice model. Physeal injury was created in the proximal tibia in 3-week-old C57BL/6 mice (WT) and CCR7-knockout mice (CCR7−/−). Tibial length was measured macroscopically and sections of the physeal injury were analyzed histologically and immunohistochemically. Height and bone volume of the tibial growth plate and bone mineral density (BMD) of the subchondral area were measured by micro-CT. Mesenchymal stem cells (MSCs) were harvested and gene expression after osteogenic differentiation was analyzed using qRT-PCR. At 1, 3 and 5 weeks postoperatively, injured tibiae of CCR7−/− mice were less shortened than those of WT mice. Bone volume of the physeal bridge was significantly lower in CCR7−/− mice than in WT mice. In contrast, BMD of the subchondral area was comparable between CCR−/− and WT mice, and between sham and operated tibiae. In osteogenic differentiation, CCR7−/− mice showed significantly lowered expression of osteogenic markers such as Osterix, Runx2 and Type X collagen. We demonstrated CCR7 depletion in mice inhibited physeal bridge formation and ameliorated growth imbalances after physeal injury.