Mesenchymal stem cells reciprocally regulate the M1/M2 balance in mouse bone marrow-derived macrophages

Mesenchymal stem cells (MSCs) have been widely studied for their applications in stem cell-based regeneration. During myocardial infarction (MI), infiltrated macrophages have pivotal roles in inflammation, angiogenesis and cardiac remodeling. We hypothesized that MSCs may modulate the immunologic environment to accelerate regeneration. This study was designed to assess the functional relationship between the macrophage phenotype and MSCs. MSCs isolated from bone marrow and bone marrow-derived macrophages (BMDMs) underwent differentiation induced by macrophage colony-stimulating factor. To determine the macrophage phenotype, classical M1 markers and alternative M2 markers were analyzed with or without co-culturing with MSCs in a transwell system. For animal studies, MI was induced by the ligation of the rat coronary artery. MSCs were injected within the infarct myocardium, and we analyzed the phenotype of the infiltrated macrophages by immunostaining. In the MSC-injected myocardium, the macrophages adjacent to the MSCs showed strong expression of arginase-1 (Arg1), an M2 marker. In BMDMs co-cultured with MSCs, the M1 markers such as interleukin-6 (IL-6), IL-1β, monocyte chemoattractant protein-1 and inducible nitric oxide synthase (iNOS) were significantly reduced. In contrast, the M2 markers such as IL-10, IL-4, CD206 and Arg1 were markedly increased by co-culturing with MSCs. Specifically, the ratio of iNOS to Arg1 in BMDMs was notably downregulated by co-culturing with MSCs. These results suggest that the preferential shift of the macrophage phenotype from M1 to M2 may be related to the immune-modulating characteristics of MSCs that contribute to cardiac repair.     

Improved self-healing performance of polymeric nanocomposites reinforced with talc nanoparticles (TNPs) and urea-formaldehyde microcapsules (UFMCs)

The present work reports the self-healing performance of the epoxy based polymeric nanocomposite coatings containing different concentrations (1 and 3 wt%) of talc nanoparticles (TNPs) modified with sodium nitrate (NaNO₃), and a fixed amount (5 wt%) of urea-formaldehyde microcapsules (UFMCs) encapsulated with linseed oil (LO). The polymeric nanocomposites were developed, coated on polished steel substrates, and their structural, thermal, and self-healing characteristics were investigated using various techniques. The successful loading (~wt 10%) of NaNO₃ into TNPs, which can be ascribed to the involvement of physio-chemical adsorption mechanism, is validated and proceeds without altering the TNPs parent lamellae structure. The performed tests elucidated that the self-release of the corrosion inhibitor (NaNO₃) from TNPs is sensitive to the pH of the solution and immersion time. In addition, the release of the linseed oil (self-healing agent) from UFMCs in response to the external damage was found to be a time-dependent process. The superior self-healing and corrosion inhibition performance of the protective polymeric nanocomposites coatings containing 3 wt% TNPs and UFMCs/LO are proven using the electrochemical impedance spectroscopy (EIS) studies. A careful selection of smart carriers, inhibitor, and self-healing agent compatible with polymeric matrix has enabled to attain decent self-healing and convincing corrosion inhibition efficiency of 99.9% and 99.5%, respectively, for polymeric nanocomposites coatings containing 3 and 1 wt% TNPs, making them attractive for many industrial applications.     

Synthesis,Characterization and Biological Evaluation of Magnolol and Honokiol Derivatives with 1,3,5-Triazine of Metformin Cyclization

Herein, we sought to evaluate the contribution of the 1,3,5-triazine ring through the metformin cyclization unit to the biological activity of magnolol and honokiol-conjugates. One of the phenolic OH groups of magnolol or honokiol was replaced by a 1,3,5-triazine ring to further explore their synthesis and medicinal versatility. In this study, a robust procedure of three steps was adopted for the synthesis of magnolol and honokiol derivatives by alkylation of potassium carbonate with a 1,3,5-triazine ring. To our knowledge, this is the first report to connect one of the phenolic OH positions of magnolol or honokiol to a 1,3,5-triazine ring cyclized by metformin. The structural characterization of three new compounds was carried out via spectroscopic techniques, i.e., ¹³C NMR, ¹H NMR, and HRMS. Surprisingly, these compounds showed no cytotoxicity against RAW 264.7 macrophages but significantly inhibited the proliferation of MCF-7 (human breast cancer cells), HepG2 (human hepatoma cells), A549 (human lung carcinoma cells), and BxPC-3 (human pancreatic carcinoma cells) tumor cell lines. Furthermore, the compounds also significantly inhibited the release of inflammatory cytokines, including nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in the lipopolysaccharide (LPS)-activated mouse cells (RAW 264.7). Among them, compound 2 demonstrated promising broad-spectrum antiproliferative potential with half inhibitory concentration (IC₅₀) values ranging from 5.57 to 8.74 µM and it significantly decreased caspase-3 and Bcl-2 expression in HepG2 cells. These interesting findings show that derivatization of magnolol and honokiol with 1,3,5-triazine affects and modulates their biological properties.     

Comparison of Phenolic Metabolites in Purified Extracts of Three Wild-Growing Herniaria L. Species and Their Antioxidant and Anti-Inflammatory Activities In Vitro

The work is aimed at phytochemical characterization and In Vitro evaluation of antioxidant actions, anti-inflammatory effects, and cytotoxicity of purified extracts from three rupturewort (Herniaria L.) species, i.e., Herniaria glabra (HG), H. polygama (HP), and H. incana herb (HIh). The total phenolic content established in the purified extracts (PEs) of HIh, HP, and HG was 29.6, 24.0, and 13.0%, respectively. Thirty-eight non-saponin metabolites were identified using LC-HR-QTOF-ESI-MS; however, only 9 were common for the studied Herniaria species. The most abundant phenolic compound in HG-PE was narcissin (7.4%), HP-PE shared 3 major constituents, namely cis-2-hydroxy-4-methoxycinnamic acid 2-O-β-glucoside (cis-GMCA, 5.8%), narcissin (5.4%), and rutin (5.3%). Almost half of HIh phenolic content (14.7%) belonged to oxytroflavoside A (7-O-methylkaempferol-3-O-[3-hydroxy-3-methylglutaryl-(1→6)]-[α-rhamnopyranosyl-(1→2)]-β-galactopyranoside). Antioxidant properties of the Herniaria PEs were evaluated employing an experimental model of human blood plasma, exposed to the peroxynitrite-induced oxidative stress. The assays demonstrated significant reduction of oxidative damage to protein and lipid plasma components (estimated by measurements of 3-nitrotyrosine, protein thiol groups, thiobarbituric acid-reactive substances), and moderate protection of its non-enzymatic antioxidant capacity. Anti-inflammatory properties of the Herniaria PEs were evaluated In Vitro as inhibitory effects against cyclooxygenases (COX-1 and -2) and concanavalin A-induced inflammatory response of the peripheral blood mononuclear cells (PBMCs). None of the studied plants showed inhibitory effects on COXs but all purified extracts partly reduced the release of interleukin 2 (IL-2) and tumor necrosis factor-alpha (TNF-α) from PBMCs, which suggested their prospective ability to up-regulate inflammatory response of the cells. The purified extract from H. glabra turned out to be the most efficient suppressor of PBMCs’ inflammatory response. Additionally, cytotoxicity of purified Herniaria extracts on PBMCs was ruled out based on In Vitro studies.     

Potential cardioprotective influence of bupropion against CCl4-triggered cirrhotic cardiomyopathy

Bupropion, an atypical anti-depressant and smoking cessation aid, attenuates complications arising from the activation of inflammatory and oxidative pathways. In this study, the effect of bupropion on an inflammatory and oxidative condition induced by carbon tetrachloride (CCl₄) namely cirrhotic cardiomyopathy (CCM) was investigated in rats. CCM was induced by intraperitoneal injection of CCl₄ (0.4 g/kg, i.p.). Bupropion was treated orally at doses 30 and 60 (mg/kg, p.o.) for 8 weeks. CCl₄ treatment significantly lowered hepatic antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH) while enhanced Malondialdehyde (MDA). Elevations in serum nitric oxide (NO) metabolites nitrite/nitrate, and cardiac tumor necrosis factor alpha (TNF-α) and interleukin 1-beta (IL-1β) levels were observed. Cirrhosis also decreased contractility in response to isoproterenol (10^?10 to 10^?5 M). The spleen weight and intrasplenic pressure increased and QTc, QRS and RR intervals prolonged. Pathological damages in the liver for example focal necrosis, fibrosis and the hepatic blocking increased. On the other hand, bupropion increased GSH, CAT and SOD and lowered MDA. Bupropion reduced NO metabolites and TNF-α levels and decreased IL-1β. The cardiac contractile force improved at maximal effect (Rmax) 10^-5 M by bupropion. The intrasplenic pressure was reduced by bupropion. Bupropion reduces QTc, QRS and RR intervals and the liver tissue damages. Bupropion played a cardioprotective role reducing inflammatory and oxidative factors. It may recover the impairment of cardiac contractility and hyperdynamic condition in CCM, and this effect could be mediated at least in part by a NO-dependent mechanism.     

Anti-Inflammatory Activity and Mechanism of Isookanin,Isolated by Bioassay-Guided Fractionation from Bidens pilosa L.

Bidens pilosa L. (Asteraceae) has been used historically in traditional Asian medicine and is known to have a variety of biological effects. However, the specific active compounds responsible for the individual pharmacological effects of Bidens pilosa L. (B. pilosa) extract have not yet been made clear. This study aimed to investigate the anti-inflammatory phytochemicals obtained from B. pilosa. We isolated a flavonoids-type phytochemical, isookanin, from B. pilosa through bioassay-guided fractionation based on its capacity to inhibit inflammation. Some of isookanin’s biological properties have been reported; however, the anti-inflammatory mechanism of isookanin has not yet been studied. In the present study, we evaluated the anti-inflammatory activities of isookanin using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. We have shown that isookanin reduces the production of proinflammatory mediators (nitric oxide, prostaglandin E₂) by inhibiting the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated macrophages. Isookanin also inhibited the expression of activator protein 1 (AP-1) and downregulated the LPS-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-jun NH₂-terminal kinase (JNK) in the MAPK signaling pathway. Additionally, isookanin inhibited proinflammatory cytokines (tumor necrosis factor-a (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-1β (IL-1β)) in LPS-induced THP-1 cells. These results demonstrate that isookanin could be a potential therapeutic candidate for inflammatory disease.     

Ab initio calculations on the clustering energies and stable structures of H(M)+ + M → H(M)2+ (M = CO and N2)

The clustering energies of the reactions, H(M)⁺+ M → H(M)⁺₂ (M = CO and N₂), were calculated by ab initio single configuration LCAO SCF MO and SCEP methods. The calculated energies are in good agreement with the experimental enthalpies.     

Resveratrol,EGCG and Vitamins Modulate Activated T Lymphocytes

Vitamins and bioactives, which are constituents of the food chain, modulate T lymphocyte proliferation and differentiation, antibody production, and prevent inflammation and autoimmunity. We investigated the effects of vitamins (vitamin A (VA), D (VD), E (VE)) and bioactives (i.e., resveratrol (Res), epigallocatechin-3-gallate (EGCG)) on the adaptive immune response, as well as their synergistic or antagonistic interactions. Freshly isolated T lymphocytes from healthy individuals were activated with anti-CD3/CD28 antibodies for 4–5 days in the presence of bioactives and were analyzed by cytofluorometry. Interleukins, cytokines, and chemokines were measured by multiple ELISA. Gene expression was measured by quantitative RT-PCR. Res and EGCG increased CD4 surface intensity. EGCG led to an increased proportion of CD8⁺ lymphocytes. Anti-CD3/CD28 activation induced exuberant secretion of interleukins and cytokines by T lymphocyte subsets. VD strongly enhanced T_h2 cytokines (e.g., IL-5, IL-13), whereas Res and EGCG favored secretion of T_h1 cytokines (e.g., IL-2, INF-γ). Res and VD mutually influenced cytokine production, but VD dominated the cytokine secretion pattern. The substances changed gene expression of interleukins and cytokines in a similar way as they did secretion. Collectively, VD strongly modulated cytokine and interleukin production and favored T_h2 functions. Resveratrol and EGCG promoted the T_h1 response. VA and VE had only a marginal effect, but they altered both T_h1 and T_h2 response. In vivo, bioactives might therefore interact with vitamins and support the outcome and extent of the adaptive immune response.     

Effect of expression of manganese superoxide dismutase in baculovirus-infected insect cells

It has previously been demonstrated that baculovirus infection of the Spodoptera frugiperda Sf-9 (Sf-9) and Trichoplusia ni BTI-Tn-5B1-4 (Tn-5B1-4) insect cell lines leads to oxidative stress as measured by protein and membrane lipid oxidation and that this oxidative damage contributes to cell death. As a result of these findings, it was hypothesized that baculovirus infection stimulates superoxide radical (O ₂ ^·— synthesis in the mitochondria and that the resulting O ₂ ^·— accumulation overwhelms the cells’ antioxidant defenses. We investigated the ability of manganese superoxide dismutase (MnSOD) expression (which reduces O ₂ ^·— to H₂O₂) to overcome the oxidative damage caused by baculovirus infection. It was found that MnSOD expression significantly reduced oxidative damage in baculovirus-infected Tn-5B1-4 cells but had no significant effect on oxidative damage in baculovirus-infected Sf-9 cells. The results are consistent with the hypothesis that O ₂ ^·— accumulation in the mitochondria is at least partially responsible for the oxidative damage resulting from the baculovirus infection of insect cells.     

Apigenin Isolated from Carduus crispus Protects against H2O2-Induced Oxidative Damage and Spermatogenic Expression Changes in GC-2spd Sperm Cells

Testicular oxidative stress is one of the most common factors underlying male infertility. Welted thistle, Carduus crispus Linn., and its bioactive principles are attracting scientific interest in treating male reproductive dysfunctions. Here, the protective effects of apigenin isolated from C. crispus against oxidative damage induced by hydrogen peroxide (H₂O₂) and dysregulation in spermatogenesis associated parameters in testicular sperm cells was investigated. Cell viabilities, ROS scavenging effects, and spermatogenic associated molecular expressions were measured by MTT, DCF-DA, Western blotting and real-time RT-PCR, respectively. A single peak with 100% purity of apigenin was obtained in HPLC conditions. Apigenin treated alone (2.5, 5, 10 and 20 µM) did not exhibit cytotoxicity, but inhibited the H₂O₂-induced cellular damage and elevated ROS levels significantly (p < 0.05 at 5, 10 and 20 µM) and dose-dependently. Further, H₂O₂-induced down-regulation of antioxidant (glutathione S-transferases m5, glutathione peroxidase 4, and peroxiredoxin 3) and spermatogenesis-associated (nectin-2 and phosphorylated-cAMP response element-binding protein) molecular expression in GC-2spd cells were attenuated by apigenin at both protein and mRNA levels (p < 0.05). In conclusion, our study showed that apigenin isolated from C. crispus might be an effective agent that can protect ROS-induced testicular dysfunctions.     

Co-delivery of Andrographolide and Notch1-targeted siRNA to Macrophages with Polymer-based Nanocarrier for Enhanced Anti-inflammation

Chronic inflammatory responses induced by macrophages play a pivotal role in the progression of atherosclerosis.In the present study,a multifunctional nanocarrier based on poly(ethylene glycol)-block-poly(L-aspartic acid)grafted with diethylenetriamine,lysine and cholic acid(PEG-PAsp(DETA)-Lys-CA2)polymer was synthesized for co-delivery of andrographolide and siRNA targeting Notch1 gene to alleviate the inflammatory response in macrophages.The nanocarrier exerted low cytotoxicity as well as high performance in drug/siRNA co-delivery.In vitro studies demonstrated the co-delivery of andrographolide and Notch1 siRNA not only significantly inhibited lipopolysaccharide(LPS)-activated interleukin-6(IL-6)and monocytes chemotactic protein 1(MCP-1)expression as well as blocked nuclear factor-κB(NF-κB)signal activation,but also interfered the Notch1 gene expression and increased anti-inflammatory cytokines such as interleukin-10(IL-10)and arginase-1 expression obviously in macrophages.These results suggested that the combination therapy based on Notch1 siRNA and andrographolide co-delivered nanocarrier,i.e.suppressing the expression of proinflammatory cytokines while simultaneously increasing anti-inflammatory factors expression,be a feasible strategy for atherosclerosis treatment.     

Study on crystallographically inequivalent protons in RbH2AsO4 using static NMR and MAS NMR

Two inequivalent protons from ¹H NMR spectra of RbH₂AsO₄ in the paraelectric phase were distinguished using static NMR and MAS NMR. From the ¹H spin–lattice relaxation times in the laboratory frame, T₁, and rotating frame, T_1ρ, of the two crystallographically inequivalent hydrogen sites, i.e., H(1) and H(2), the temperature dependences of T₁ and T_1ρ for H(1) were related to the reorientational motion. The shorter H(1) bonds give rise to stronger H-bonds, and protons involved in stronger H-bonds have long relaxation times. Consequently, the RbH₂AsO₄ structure has two crystallographically inequivalent sites with two different hydrogen-bond lengths.     

Bioactive Tryptophan-Based Copper Complex with Auxiliary β-Carboline Spectacle Potential on Human Breast Cancer Cells: In Vitro and In Vivo Studies

Biocompatible tryptophan-derived copper (1) and zinc (2) complexes with norharmane (β-carboline) were designed, synthesized, characterized, and evaluated for the potential anticancer activity in vitro and in vivo. The in vitro cytotoxicity of both complexes 1 and 2 were assessed against two cancerous cells: (human breast cancer) MCF7 and (liver hepatocellular cancer) HepG2 cells with a non-tumorigenic: (human embryonic kidney) HEK293 cells. The results exhibited a potentially decent selectivity of 1 against MCF7 cells with an IC₅₀ value of 7.8 ± 0.4 μM compared to 2 (less active, IC₅₀ ~ 20 μM). Furthermore, we analyzed the level of glutathione, lipid peroxidation, and visualized ROS generation to get an insight into the mechanistic pathway and witnessed oxidative stress. These in vitro results were ascertained by in vivo experiments, which also supported the free radical-mediated oxidative stress. The comet assay confirmed the oxidative stress that leads to DNA damage. The histopathology of the liver also ascertained the low toxicity of 1.     

Anti-Inflammatory Effects of 6-Methylcoumarin in LPS-Stimulated RAW 264.7 Macrophages via Regulation of MAPK and NF-κB Signaling Pathways

Persistent inflammatory reactions promote mucosal damage and cause dysfunction, such as pain, swelling, seizures, and fever. Therefore, in this study, in order to explore the anti-inflammatory effect of 6-methylcoumarin (6-MC) and suggest its availability, macrophages were stimulated with lipopolysaccharide (LPS) to conduct an in vitro experiment. The effects of 6-MC on the production and levels of pro-inflammatory cytokines (interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α) and inflammatory mediators (nitric oxide (NO), prostaglandin E₂ (PGE₂)) in LPS-stimulated RAW 264.7 cells were examined. The results showed that 6-MC reduced the levels of NO and PGE₂ without being cytotoxic. In addition, it was demonstrated that the increase in the expression of pro-inflammatory cytokines caused by LPS stimulation, was decreased in a concentration-dependent manner with 6-MC treatment. Moreover, Western blot results showed that the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), which increased with LPS treatment, were decreased by 6-MC treatment. Mechanistic studies revealed that 6-MC reduced the phosphorylation of the mitogen-activated protein kinase (MAPK) family and IκBα in the MAPK and nuclear factor-kappa B (NF-κB) pathways, respectively. These results suggest that 6-MC is a potential therapeutic agent for inflammatory diseases that inhibits inflammation via the MAPK and NF-κB pathways.     

Enhanced photovoltaic characterization and charge transport of TIO2 nanoparticles/nanotubes composite photoanode based on indigo carmine dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) have established themselves as an alternative to conventional solar cells owing to their remarkably high power conversion efficiency, longtime stability and low-cost production. DSSCs composed of a dyed oxide semiconductor photoanode, a redox electrolyte and a counter electrode. In these devices, conversion efficiency is achieved by ultra-fast injection of an electron from a photo excited dye into the conduction band of metal oxide followed by subsequent dye regeneration and holes transportation to the counter electrode. The energy conversion efficiency of DSSC is to be dependent on the morphology and structure of the dye adsorbed metal oxide photoanode. Worldwide considerable efforts of DSSCs have been invested in morphology control of photoanode film, synthesis of stable optical sensitizers and improved ionic conductivity electrolytes. In the present investigation, a new composite nano structured photoanodes were prepared using TiO₂ nano tubes (TNTs) with TiO₂ nano particles (TNPs). TNPs were synthesized by sol–gel method and TNTs were prepared through an alkali hydrothermal transformation. Working photoanodes were prepared using five pastes of TNTs concentrations of 0, 10, 50, 90, and 100 % with TNPs. The DSSCs were fabricated using Indigo carmine dye as photo sensitizer and PMII (1-propyl-3-methylimmidazolium iodide) ionic liquid as electrolyte. The counter electrode was prepared using Copper sulfide. The structure and morphology of TNPs and TNTs were characterized by X-ray diffraction and electron microscopes (TEM and SEM). The photocurrent efficiency is measured using a solar simulator (100 mW/cm²). The prepared composite TNTs/TNPs photoanode could significantly improve the efficiency of dye-sensitized solar cells owing to its synergic effects, i.e. effective dye adsorption mainly originated from TiO₂ nanoparticles and rapid electron transport in one-dimensional TiO₂ nanotubes. The results of the present investigation suggested that the DSSC based on 10 % TNTs/TNPs showed better photovoltaic performance than cell made pure TiO₂ nanoparticles. The highest energy-conversion efficiency of 2.80 % is achieved by composite TNTs (10 %)/TNPs film, which is 68 % higher than that pure TNPs film and far larger than that formed by bare TNTs film (94 %). The charge transport and charge recombination behaviors of DSSCs were investigated by electrochemical impedance spectra and the results showed that composite TNTs/TNPs film-based cell possessed the lowest transfer resistances and the longest electron lifetime. Hence, it could be concluded that the composite TNTs/TNPs photoanodes facilitate the charge transport and enhancing the efficiencies of DSSCs.     

The rate constants of the gas-phase reactions K + Cl ⇆ K+ + Cl− and KCl + M ⇆ K+ + Cl− + M from measurements in atmospheric pressure flames

Mass spectrometric studies of the ions present in H₂/O₂/N₂ flames with potassium and chlorine added have demonstrated that ionization can occur in the forward steps of K + Cl ? K⁺ + Cl^? (II), KCl + M ? K⁺ + Cl^? + M (IV), where M is any third body. Variations of [K⁺] with time in these systems have been measured and establish that the rate coefficients (in ml molecule^?1 s^?1) of the ion-producing steps are k₂ = 5 × 10^?10T^{?$\text{1}\text{2}$} exp(?10 500/T) and k₄ = 2.2 × 10⁷T^?3.5 × exp(?60 800/T). Coefficients for ion-ion recombination have been obtained from k₂ and k₄ using the equilibrium constants of (II) and (IV) and are k_?2 = 1.7 × 10^?9T^{?$\text{1}\text{2}$} and k_?4 = 1.1 × 10^?17T^?3, with each one in the ml molecule^?1 s^?1 system of units. Replacement of the N₂ in one of these flames with sufficient Ar to maintain the temperature constant leaves the measured k₂ and k_?2 unchanged, but lowers the observed k₄ and k_?4. This confirms that ion-recombination in the backward step in (II) is a two-body process, whereas in (IV) it is termolecular.     

Synthesis and characterization of bis-isonitrile complexes Cp2M(CNR)2 (M = Ti,Zr; R = 2,6-dimethylphenyl)

Bis-isonitrile complexes Cp₂M(CNR)₂ (M  Ti, Zr), where RNC is the sterically hindered 2,6-dimethylphenyl isonitrile, can be prepared in high yield by reduction of Cp₂MCl₂ with magnesium in THF solution in the presence of the isonitrile. ¹H NMR spectroscopy reveals that with the titanium complex dissociation of the isonitrile ligands takes place in solution.     

Zur Darstellung und Struktur von M1?LnTa3O9 (Ln = Pr,Nd) Röntgenographische und elektronenmikroskopische Untersuchungen

Preparation and Structure of M1? LnTa₃O₉ (Ln = Pr, Nd), X-Ray and Electronmicroscopical Investigations New ternary compounds M1? LnTa₃O₉ (Ln = Pr, Nd) could be prepared by chemical transport reaction in a temperature gradient T₂ → T₁ (T₂ = 1100°C; T₁ = 1000°C; CI₂ as transport agent). M1 NdTa₃O₉ crystallizes in the monoclinic space group P 2₁/m with a = 5.3840(9) Å, b = 7.550(1) Å, c = 8.1911(9) Å and β = 92.46(1)°. The structure was refined to give R = 6.29% and R_w = 6.20%. It is built of double and single chains of corner-sharing TaO₆ octahedra extended along the b-axis. Tunnels running along [010] are created by the framework of TaO₆ octahedra. Ln (Ln = Pr, Nd) is located in these tunnels to levels of y = 1/4 and 3/4. A structure refinement for isostructural M1? PrTa₃O₉ led to a = 5.4051(7) Å, b = 7.5680(2) Å, c = 8.1964(9) Å, β = 92.38(2)° and R = 7.72%, R_w = 7.57%. By grinding in an agate mortar M1? LnTa₃O₉ transforms into M2? LnTa₃O₉, a new modification with a higher density. High resolution transmission electron microscopy images of the M1? PrTa₃O₉ structure were made along the [010] direction. They could be interpreted by comparing them with images calculated on the basis of the multi-slice method.     

Crystal Structures,Dimorphism and Lithium Mobility of Li7MO6 (M = Bi,Ru, Os)

Li₇MO₆ (M = Bi, Ru, Os) have been synthesized by solid state reaction of Li₂O with Bi₂O₃, or MO₂ (M = Ru, Os) and characterized using powder X‐ray diffraction, differential scanning calorimetry, magnetic susceptibility (for M = Ru, Os), ionic conductivity and ⁶Li solid state NMR (for M = Bi) measurements. All three compounds exhibit a temperature induced triclinic – rhombohedral phase transition. Structures of the new low temperature triclinic phases have been refined by the Rietveld method from powder X‐ray data using atomic parameters of Li₇TaO₆ as a starting model ( Li₇BiO₆ : triclinic, , a = 5.5071(1), b = 6.0425(1), c = 5.5231(1) Å, α = 116.912(1), β = 120.867(1), γ = 62.234(1)°, V = 133.96(1) ų, Z = 1, T = 230 K; Li₇RuO₆ : triclinic, , a = 5.3654(1), b = 5.8584(1), c = 5.3496(1) Å, α = 117.182(1), β = 119.117(1), γ = 62.632(1)°, V = 124.43(1) ų, Z = 1, T = 295 K; Li₇OsO₆ : triclinic, , a = 5.3786(1), b = 5.8725(1), c = 5.3591(1) Å, α = 117.193(1), β = 119.277(1), γ = 62.700(1)°, V = 125.15(1) ų, Z = 1, T = 295 K). Upon cooling, Li₇RuO₆ and Li₇OsO₆ undergo a magnetic transition at 12 and 13 K, respectively, from the paramagnetic to the antiferromagnetic state. The higher ionic conductivity of Li₇BiO₆ at T < 300 °C, as compared to Li₇RuO₆ and Li₇OsO₆, can be ascribed to the undergoing of the triclinic – rhombohedral transition at a much lower temperature. At T > 300 °C, the ionic conductivity of all three compounds increases sharply due to the melting of the lithium sublattice; for Li₇RuO₆ and Li₇OsO₆ the latter effect is superimposed by the phase transitions to the rhombohedral modifications.     

Bioinspired Platelet-Anchored Electrospun Meshes for Tight Inflammation Manipulation and Chronic Diabetic Wound Healing

Tight manipulation of the initial leukocytes infiltration and macrophages plasticity toward the M2 phenotype remain a challenge for diabetic wound healing. Inspired by the platelet function and platelet–macrophage interaction, a platelet-anchored polylactic acid-b-polyethylene glycol-b-polylactic acid (PLA-PEG-PLA) electrospun dressing is developed for inflammatory modulation and diabetic wounds healing acceleration. PLA-PEG-PLA electrospun meshes encapsulated with thymosin β4 (Tβ4) and CaCl₂ is fabricated with electrospinning, followed by immersion of electrospun mesh in platelet-rich plasma to firmly anchor the platelets. It is demonstrated that the anchored platelets on electrospun mesh can enhance the initial macrophage recruitment and control the Tβ4 release from electrospun meshes to facilitate the macrophages polarization to the M2 phenotype. The inflammatory regulation promotes the expression of vascular endothelial growth factor and the migration of vascular endothelial cells for angiogenesis, resulting in accelerated diabetic wounds healing. Therefore, this work paved a new way to design platelet-inspired electrospun meshes for inflammation manipulation and diabetic wound healing.