Two-Dimensional Covalent Framework Derived Nonprecious Transition Metal Single-Atomic-Site Electrocatalyst toward High-Efficiency Oxygen Reduction.

Designing an active, stable, and nonprecious metal catalyst substitute for Pt in the oxygen reduction reaction (ORR) is highly demanded for energy-efficient and cost-effective prototype devices. Single-atomic-site catalysts (SASCs) have been widely concerning because of their maximum atomic utilization and precise structural regulation. Despite being challenging, the controllable synthesis of SASCs is crucial for optimizing ORR activity. Here, we demonstrate an ultrathin organometallic framework template-assisted pyrolysis strategy to synthesize SASCs with a unique two-dimensional (2D) architecture. Electrochemical measurements revealed that Fe-SASCs displayed an excellent ORR activity in an alkaline media, having a half-wave potential and a diffusion-limited current density comparable to those of commercial Pt/C. Remarkably, the durability and methanol tolerance of Fe-SASCs were even superior to those of Pt/C. Furthermore, Fe-SASCs displayed a maximum power density of 142 mW cm-2 with a current density of 235 mA cm-2 as a cathode catalyst in a zinc-air battery, showing its great potential for practical applications.

A Two-Dimensional van der Waals Heterostructure with Isolated Electron-Deficient Cobalt Sites toward High-Efficiency CO2 Electroreduction.

Electrochemical CO2 conversion is a promising way for sustainable chemical fuel production, yet the conversion efficiency is strongly limited by the sluggish kinetics and complex reaction pathways. Here we report the ultrathin conjugated metalloporphyrin covalent organic framework epitaxially grown on graphene as a two-dimensional van der Waals heterostructure to catalyze CO2 reduction. Operando X-ray absorption and density functional theory calculations reveal the strong interlayer coupling leads to electron-deficient metal centers and speeds up electrocatalysis. The Co(III)-N4 centers exhibit a CO Faradaic efficiency of 97% at a partial current density of 8.2 mA cm-2 in an H-cell, along with a stable running over 30 h. The selectivity of CO approached 99% with a partial current density of 191 mA cm-2 in a liquid flow cell, and the turnover frequency achieved 50 400 h-1 at -1.15 V vs RHE, outperforming most reported organometallic frameworks. This work highlights the key role of strong electronic coupling between van der Waals layers for accelerating the dynamics of CO2 conversion.

Enhanced Electrochemical Methanation of Carbon Dioxide at the Single-Layer Hexagonal Boron Nitride/Cu Interfacial Perimeter.

The electrochemical conversion of CO2 to valuable fuels is a plausible solution to meet the soaring need for renewable energy sources. However, the practical application of this process is limited by its poor selectivity due to scaling relations. Here we introduce the rational design of the monolayer hexagonal boron nitride/copper (h-BN/Cu) interface to circumvent scaling relations and improve the electrosynthesis of CH4. This catalyst possesses a selectivity of >60% toward CH4 with a production rate of 15 µmol·cm-2·h-1 at -1.00 V vs RHE, along with a much smaller decaying production rate than that of pristine Cu. Both experimental and theoretical calculations disclosed that h-BN/Cu interfacial perimeters provide specific chelating sites to immobilize the intermediates, which accelerates the conversion of *CO to *CHO. Our work reports a novel Cu catalyst engineering strategy and demonstrates the prospect of monolayer h-BN contributing to the design of heterostructured CO2 reduction electrocatalysts for sustainable energy conversion.

Cloning, expression, and characterization of an arabitol dehydrogenase and coupled with NADH oxidase for effective production of L-xylulose.

A novel arabitol dehydrogenase (ArDH) gene was cloned from a bacterium named Aspergillus nidulans and expressed heterologously in Escherichia coli. The purified ArDH exhibited the maximal activity in pH 9.5 Tris-HCl buffer at 40 °C, showed Km and Vmax of 1.2 mg/mL and 9.1 U/mg, respectively. The ArDH was used to produce the L-xylulose and coupled with the NADH oxidase (Nox) for the regeneration of NAD+. In further optimization, a high conversion of 84.6% in 8 hours was achieved under the optimal conditions: 20 mM of xylitol, 100 µM NAD+ in pH 9.0 Tris-HCl buffer at 30 °C. The results indicated the coupling system with cofactor regeneration provides a promising approach for L-xylulose production from xylitol.

Graphdiyne/Graphene Heterostructure: A Universal 2D Scaffold Anchoring Monodispersed Transition-Metal Phthalocyanines for Selective and Durable CO2 Electroreduction.

Electrochemical CO2 reduction (CO2R) is a sustainable way of producing carbon-neutral fuels, yet the efficiency is limited by its sluggish kinetics and complex reaction pathways. Developing active, selective, and stable CO2R electrocatalysts is challenging and entails intelligent material structure design and tailoring. Here we show a graphdiyne/graphene (GDY/G) heterostructure as a 2D conductive scaffold to anchor monodispersed cobalt phthalocyanine (CoPc) and reduce CO2 with an appreciable activity, selectivity, and durability. Advanced characterizations, e.g., synchrotron-based X-ray absorption spectroscopy (XAS), and density functional theory (DFT) calculation disclose that the strong electronic coupling between GDY and CoPc, together with the high surface area, abundant reactive centers, and electron conductivity provided by graphene, synergistically contribute to this distinguished electrocatalytic performance. Electrochemical measurements revealed a high FECO of 96% at a partial current density of 12 mA cm-2 in a H-cell and an FECO of 97% at 100 mA cm-2 in a liquid flow cell, along with a durability over 24 h. The per-site turnover frequency of CoPc reaches 37 s-1 at -1.0 V vs RHE, outperforming most of the reported phthalocyanine- and porphyrin-based electrocatalysts. The usage of the GDY/G heterostructure as a scaffold can be further extended to other organometallic complexes beyond CoPc. Our findings lend credence to the prospect of the GDY/G hybrid contributing to the design of single-molecule dispersed CO2R catalysts for sustainable energy conversion.

Compressive Resistances and Failure Modes of Abutments With Different Transgingival Heights and Types on Internal Conical Connected Implants.

PURPOSE: This study aimed to research the effect of different transgingival heights (THs) and types of abutments on performances including the compressive resistances and fracture modes of abutments on internal conical connected implants. MATERIALS AND METHODS: Three groups were established: a 1-piece zirconia abutment group (group A), a 2-piece zirconia abutment group (group B), and a 1-piece titanium abutment group (group C). Three THs (2, 3.5, and 5 mm, n = 6) were set as the subgroups of each group. All groups were subjected to a compressive resistance test at a 30 degree angle. The main failure modes were analyzed using scanning electron microscopy and a stereomicroscope. RESULTS: The compressive resistances of the abutments on the internal conical connected implants were significantly related to the TH (P = 0.004), the type of abutment (P < 0.0001), and the combined effect (P < 0.0001). All of the subgroups in group C exhibited the greatest compressive loads at the same TH. Different types of abutments had different failure modes. CONCLUSIONS: Both the TH and the type of abutments influenced compressive resistances of the implant-abutment complexes.

Designing Surface and Interface Structures of Copper-Based Catalysts for Enhanced Electrochemical Reduction of CO2 to Alcohols.

Electrochemical CO2 reduction (ECR) has emerged as a promising solution to address both the greenhouse effect caused by CO2 emissions and the energy shortage resulting from the depletion of nonrenewable fossil fuels. The production of multicarbon (C2+) products via ECR, especially high-energy-density alcohols, is highly desirable for industrial applications. Copper (Cu) is the only metal that produces alcohols with appreciable efficiency and kinetic viability in aqueous solutions. However, poor product selectivity is the main technical problem for applying the ECR technology in alcohol production. Extensive research has resulted in the rational design of electrocatalyst architectures using various strategies. This design significantly affects the adsorption energetics of intermediates and the reaction pathways for alcohol production. In this review, we focus on the design of effective catalysts for ECR to alcohols, discussing fundamental principles, innovative strategies, and mechanism understanding. Furthermore, the challenges and prospects in utilizing Cu-based materials for alcohol production via ECR are discussed.

3D Printed Porous Zirconia Biomaterials based on Triply Periodic Minimal Surfaces Promote Osseointegration In Vitro by Regulating Osteoimmunomodulation and Osteo/Angiogenesis.

The triply periodic minimal surface (TPMS) is a highly useful structure for bone tissue engineering owing to its nearly nonexistent average surface curvature, high surface area-to-volume ratio, and exceptional mechanical energy absorption properties. However, limited literature is available regarding bionic zirconia implants using the TPMS structure for bone regeneration. Herein, we employed the digital light processing (DLP) technology to fabricate four types of zirconia-based TPMS structures: P-cell, S14, IWP, and Gyroid. For cell proliferation, the four porous TPMS structures outperformed the solid zirconia group (P-cell > S14 > Gyroid > IWP > ZrO2). In vitro assessments on the biological responses and osteogenic properties of the distinct porous surfaces identified the IWP and Gyroid structures as promising candidates for future clinical applications of porous zirconia implants because of their superior osteogenic capabilities (IWP > Gyroid > S14 > P-cell > ZrO2) and mechanical properties (ZrO2 > IWP > Gyroid > S14 > P-cell). Furthermore, the physical properties of the IWP/Gyroid surface had more substantial effects on bone immune regulation by reducing macrophage M1 phenotype polarization while increasing M2 phenotype polarization compared with the solid zirconia surface. Additionally, the IWP and Gyroid groups exhibited enhanced immune osteogenesis and angiogenesis abilities. Collectively, these findings highlight the substantial impact of topology on bone/angiogenesis and immune regulation in promoting bone integration.

Heparinase III with High Activity and Stability: Heterologous Expression, Biochemical Characterization, and Application in Depolymerization of Heparin.

A novel heparinase III from Pedobacter schmidteae (PsHep-III) with high activity and good stability was successfully cloned, expressed, and characterized. PsHep-III displayed the highest specific activity ever reported of 192.8 U mg-1 using heparin as the substrate. It was stable at 25 °C with a half-life of 323 h in an aqueous solution. PsHep-III was employed for the depolymerization of heparin, and the enzymatic hydrolyzed products were analyzed with gel permeation chromatography and high-performance liquid chromatography. PsHep-III can break glycosidic bonds in heparin like →4]GlcNAc/GlcNAc6S/GlcNS/GlcNS6S/GlcN/GlcN6S(1 → 4)ΔUA/ΔUA2S[1 → and efficiently digest heparin into seven disaccharides including N-acetylated, N-sulfated, and N-unsubstituted modification, with molecular masses of 503, 605, 563, 563, 665, 360, and 563 Da, respectively. These results indicated that PsHep-III with broad substrate specificity could be combined with heparinase I to overcome the low selectivity at the N-acetylated modification binding sites of heparinase I. This work will contribute to the application of PsHep-III for characterizing heparin and producing low-molecular-weight heparin effectively.

Accuracy of Modern Intraocular Lens Formulas in Highly Myopic Eyes Implanted With Plate-Haptic Intraocular Lenses.

PURPOSE: To evaluate the predictive accuracy of modern intraocular lens (IOL) formulas and axial length (AL) adjusted traditional IOL formulas, including Wang-Koch and Cooke-modified AL (CMAL) method, in long eyes with plate-haptic IOLs, and to compare refractive prediction error variances with C-loop IOLs. DESIGN: Retrospective consecutive case series study. METHODS: Data from 391 eyes with Zeiss 509 M and 302 eyes with Alcon SN6CWS implants in highly myopic patients, following cataract surgery from January 2019 to November 2023, were collected. One eye per patient was selected. Predictive outcomes of 15 modern formulas (Barrett Universal II (BU II), Cooke K6 (K6), Emmetropia Verifying Optical (EVO) 2.0, Hoffer-QST, Kane, Karmona, Ladas AI, Naeser 2, Olsen, Pearl-DGS, Radial Basis Function (RBF) 3.0, T2, VRF-G, Zhu-Lu, and Z-Calc) and 4 traditional IOL formulas (Haigis, Hoffer Q, Holladay 1, and SRK/T) with AL adjusted methods, were evaluated. The mean prediction error, mean absolute prediction error (MAE), root-mean-square absolute prediction error (RMSAE) and the proportions of eyes with PEs within ±0.25 Diopter (D), ±0.50 D, ±0.75 D, and ±1.00 D were analyzed. Top 10 RMSAE-ranked formulas underwent further subgroup analysis based on AL, anterior chamber depth (ACD), and keratometry (K). RESULTS: For the 509 M group, RMSAE ranking for the top 10 IOL formulas were the RBF 3.0 (0.432), Zhu-Lu (0.436), Olsen (0.436), EVO 2.0 (0.437), Pearl-DGS (0.447), K6 (0.452), VRF-G (0.454), Naeser 2 (0.464), Haigis-CMAL (0.465) and Karmona (0.477). Karmona and Naeser 2 showed poorer performance in the extremely long AL and steep K subgroups, respectively (p ≤ 0.042). Haigis-CMAL accuracy was significantly lower in shallow ACD and flat K subgroups (P ≤ .045). The SN6CWS group showed significantly lower MAE and RMSAE compared to the 509 M group for the BU II, EVO 2.0, Hoffer-QST, Kane, Pearl-DGS, and Zhu-Lu formulas (P ≤ .024). CONCLUSIONS: In long eyes with plate-haptic IOLs, RBF 3.0 performed best, closely followed by Zhu-Lu, Olsen, and EVO 2.0; Karmona and Naeser 2 are discouraged for extreme AL and steep K conditions, respectively; Haigis-CMAL is not suggested for shallow ACD and flat K cases. Refractive outcomes in eyes implanted with a C-loop design IOL were more accurate than for those implanted with a plate-haptic design, for most tested formulas.

Salivary signatures of oral-brain communication in sleep bruxers.

Introduction: Microbiota and their interaction with hosts have been of great interest in brain research in recent years. However, the role of oral microbiota in mental illness and the underlying mechanism of oral-brain communication remains elusive. Sleep bruxism (SB) is an oral parafunctional activity related to the nervous system and is considered a risk factor for harmful clinical consequences and severe systemic conditions. Exploring the connection between oral microbiota and sleep bruxism may deepen our understanding of the complex relationship between oral-brain axis and provide insights for treatment. Methods: In this study, salivary samples were collected from 22 individuals with SB and 21 healthy controls, and metagenomics with metabolomics was performed. Nonparametric Wilcoxon test were applied for the statistical analysis between the two groups. Microbial dysbiosis and altered oral metabolites were found in the SB individuals. Results: The characteristic metabolite N-acetylglucosamine (GlcNAc) (VIP=8.4823, P<0.05) was correlated to a statistically lower Streptococcus mitis level in SB individuals. Salivary IFN-g level and IFN-g/IL-4 ratio were detected with significant changes in a chip assay. Amino acid metabolism pathways were upregulated, and the pathway with the largest number of differentially expressed genes is related to amino-tRNA charging pathway, while the most significantly enriched pathway is related to arginine biosynthesis. Neurotransmitter-associated pathways with glutamatergic and GABAergic synapses and cardiovascular system-related pathways were enriched in the SB group. Discussion: These results indicate a possible neuroimmune regulatory network of oral-brain communication in SB, which helps explain the mechanism of the oral microbiome with the host in sleep bruxers and provides a reference for early clinical and therapeutic intervention to improve the diagnosis and treatment of SB and similar diseases.

Structure-Function Correlation and Dynamic Restructuring of Cu for Highly Efficient Electrochemical CO2 Conversion.

The increasing global demand for sustainable energy sources and emerging environmental issues have pushed the development of energy conversion and storage technologies to the forefront of chemical research. Electrochemical carbon dioxide (CO2 ) conversion provides an attractive approach to synthesizing fuels and chemical feedstocks using renewable energy. On the path to deploying this technology, basic and applied scientific hurdles remain. Copper, as the only metal catalyst that is capable to produce C2+ fuels from CO2 reduction (CO2 R), still faces challenges in the improvement of electrosynthesis pathways for highly selective fuel production. In this regard, mechanistically understanding CO2 R on Cu-based electrocatalysts, particularly identifying the structure-function correlation, is crucial. Here, a broad view of the variable structural parameters and their complex interplay in CO2 R catalysis on Cu was given, with the purpose of providing deep insights and guiding the future rational design of CO2 R electrocatalysts. First, this Review described the progress and recent advances in the development of well-defined nanostructured catalysts and the mechanistic understanding on the influences from a particular structure of a catalyst, such as facet, defects, morphology, oxidation state, composition, and interface. Next, the in-situ dynamic restructuring of Cu was presented. The importance of operando characterization methods to understand the catalyst structure-sensitivity was also discussed. Finally, some perspectives on the future outlook for electrochemical CO2 R were offered.

Recent Strategies for the Immobilization of Therapeutic Enzymes.

Therapeutic enzymes play important roles in modern medicine due to their high affinity and specificity. However, it is very expensive to use them in clinical medicine because of their low stability and bioavailability. To improve the stability and effectiveness of therapeutic enzymes, immobilization techniques have been employed to enhance the applications of therapeutic enzymes in the past few years. Reported immobilization techniques include entrapment, adsorption, and covalent attachment. In addition, protein engineering is often used to improve enzyme properties; however, all methods present certain advantages and limitations. For carrier-bound immobilization, the delivery and release of the immobilized enzyme depend on the properties of the carrier and enzyme. In this review, we summarize the advantages and challenges of the current strategies developed to deliver therapeutic enzymes and provide a future perspective on the immobilization technologies used for therapeutic enzyme delivery.

[Berberine promotes osteogenic differentiation of rat adipose-derived stem cells through JNK signaling pathway].

PURPOSE: This study aimed at exploring the effect of berberine (C20H18NO4) on osteogenic differentiation of rat adipose-derived stem cells(ADSCs) and clarifying the related mechanism. METHODS: ADSCs were subjected to 5, 10, 20 µmol/L berberine culture solution. The untreated ADSCs were set as the control group. Cell proliferation activity was determined by MTT method. Alkaline phosphatase (ALP) staining, semi-quantitative assay and alizarin red staining (ARS) were applied to analyze the effect of berberine on osteogenic differentiation of ADSCs. The phosphorylation level of c-Jun amino terminal kinase (JNK) protein was tested by Western blot. Runx2, OCN were tested by Western blot before and after application of JNK pathway inhibitor SP600125. SPSS 22.0 software package was used for statistical analysis. RESULTS: There was no significant difference on cell proliferation activity of ADSCs treated with 5, 10 and 20 µmol/L berberine at 1, 3 and 7 day(P>0.05). ALP staining and ARS staining in groups treated by berberine were significantly darker than those of the control group, and ALP protein secretion in the experimental group was significantly up-regulated (P<0.05). The phosphorylation level of JNK was increased after treated with 10 µmol/L berberine culture medium. The expression of osteogenic related proteins Runx2 and OCN was up-regulated in the experimental group. After inhibition of JNK signaling pathway, the expression of Runx2 and OCN was down-regulated. CONCLUSIONS: Berberine has no effect on cell proliferation of ADSCs, and can up-regulate osteogenic differentiation of ADSCs through activation of JNK signaling pathway.

A novel chondroitin AC lyase from Pedobacter xixiisoli: Cloning, expression, characterization and the application in the preparation of oligosaccharides.

Chondroitin AC lyase can efficiently hydrolyze chondroitin sulfate (CS) to low molecule weight chondroitin sulfate, which has been widely used in clinical therapy, including anti-tumor, anti-oxidation, hypolipidemic, and anti-inflammatory. In this work, a novel chondroitin AC lyase from Pedobacter xixiisoli (PxchonAC) was cloned and overexpressed in Escherichia coli BL21 (DE3). The characterization of PxchonAC showed that it has specific activities on chondroitin sulfate A, Chondroitin sulfate C and hyaluronic acid with 428.77, 270.57, and 136.06 U mg-1, respectively. The Km and Vmax of PxchonAC were 0.61 mg mL-1 and 670.18 U mg-1 using chondroitin sulfate A as the substrate. The enzyme had a half-life of roughly 660 min at 37 °C in the presence of Ca2+ and remained a residual activity of 54 % after incubated at 4 °C for 25 days. Molecular docking revealed that Asn123, His223, Tyr232, Arg286, Arg290, Asn372, and Glu374 were mainly involved in the substrate binding. The enzymatic hydrolysis product was analyzed by gel permeation chromatography, demonstrating PxchonAC could hydrolyze CS efficiently.

Microstructures, mechanical, and biological properties of a novel Ti-6V-4V/zinc surface nanocomposite prepared by friction stir processing.

BACKGROUND: The interaction between the material and the organism affects the survival rate of the orthopedic or dental implant in vivo. Friction stir processing (FSP) is considered a new solid-state processing technology for surface modification. PURPOSE: This study aims to strengthen the surface mechanical properties and promote the osteogenic capacity of the biomaterial by constructing a Ti-6Al-4V (TC4)/zinc (Zn) surface nanocomposites through FSP. METHODS: FSP was used to modify the surface of TC4. The microstructures and mechanical properties were analyzed by scanning electron microscopy, transmission electron microscopy, nanoindentation and Vickers hardness. The biological properties of the modified surface were evaluated by the in vitro and in vivo study. RESULTS: The results showed that nanocrystalline and numerous ß regions, grain boundary α phase, coarser acicular α phase and finer acicular martensite α' appeared because of the severe plastic deformation caused by FSP, resulting in a decreased elastic modulus and an increased surface hardness. With the addition of Zn particles and the enhancement of hydrophilicity, the biocompatibility was greatly improved in terms of cell adhesion and proliferation. The in vitro osteogenic differentiation of rat bone marrow stromal cells and rapid in vivo osseointegration were enhanced on the novel TC4/Zn metal matrix nanocomposite surface. CONCLUSION: These findings suggest that this novel TC4/Zn surface nanocomposite achieved by FSP has significantly improved mechanical properties and biocompatibility, in addition to promoting osseointegration and thus has potential for dental and orthopedic applications.

Bone morphogenetic protein 2 promotes osteogenesis of bone marrow stromal cells in type 2 diabetic rats via the Wnt signaling pathway.

Type 2 diabetes mellitus impairs osteogenesis in bone marrow stromal cells (BMSCs). Bone morphogenetic protein 2 (BMP2) has been extensively applied for bone defect restoration and has been shown to activate the Wnt signaling pathway. The objective of this study was to investigate the effects of BMP2 on the cell proliferation and osteogenesis of type 2 diabetic BMSCs in rats and explore whether BMP2 induced osteogenesis via the stimulation of Wnt signaling pathway. The cell experiments were divided into DM (diabetic BMSCs), BMP25 (induced with 25ng/ml BMP2), BMP100 (induced with 100ng/ml BMP2) and BMP25 +XAV groups. All cells with or without the different concentrations of BMP2 were cultured under the same experimental conditions. The in vitro results indicated that BMP2 enhanced cell proliferation by 130%-157% and osteogenic differentiation by approximately two-fold in type 2 diabetic BMSCs. The expression levels of ß-catenin, cyclin D1, Runx2 and c-myc related to the Wnt signaling pathway were also upregulated from 180% to 212% in BMP2-induced type 2 diabetic rat BMSCs, while the level of GSK3ß decreased to 43%. In BMP2-induced type 2 diabetic BMSCs with calcium phosphate cement (CPC) scaffolds for osteoblast study in vivo, the appearance of newly formed bone dramatically increased to 175% compared with type 2 diabetic BMSCs. These data demonstrated that BMP2 enhanced bone regeneration in diabetic BMSCs by stimulating the Wnt signaling pathway with the accumulation of ß-catenin and the depressed expression of GSK3ß. Diabetic BMSCs associated with BMP2 might be a potential tissue-engineered construct for bone defects in type 2 diabetes mellitus.

Proliferation and osteogenic differentiation of rat BMSCs on a novel Ti/SiC metal matrix nanocomposite modified by friction stir processing.

The aims of this study were to fabricate a novel titanium/silicon carbide (Ti/SiC) metal matrix nanocomposite (MMNC) by friction stir processing (FSP) and to investigate its microstructure and mechanical properties. In addition, the adhesion, proliferation and osteogenic differentiation of rat bone marrow stromal cells (BMSCs) on the nanocomposite surface were investigated. The MMNC microstructure was observed by both scanning and transmission electron microscopy. Mechanical properties were characterized by nanoindentation and Vickers hardness testing. Integrin ß1 immunofluorescence, cell adhesion, and MTT assays were used to evaluate the effects of the nanocomposite on cell adhesion and proliferation. Osteogenic and angiogenic differentiation were evaluated by alkaline phosphatase (ALP) staining, ALP activity, PCR and osteocalcin immunofluorescence. The observed microstructures and mechanical properties clearly indicated that FSP is a very effective technique for modifying Ti/SiC MMNC to contain uniformly distributed nanoparticles. In the interiors of recrystallized grains, characteristics including twins, fine recrystallized grains, and dislocations formed concurrently. Adhesion, proliferation, and osteogenic and angiogenic differentiation of rat BMSCs were all enhanced on the novel Ti/SiC MMNC surface. In conclusion, nanocomposites modified using FSP technology not only have superior mechanical properties under stress-bearing conditions but also provide improved surface and physicochemical properties for cell attachment and osseointegration.

High-Fat Diet/Low-Dose Streptozotocin-Induced Type 2 Diabetes in Rats Impacts Osteogenesis and Wnt Signaling in Bone Marrow Stromal Cells.

Bone regeneration disorders are a significant problem in patients with type 2 diabetes mellitus. Bone marrow stromal cells (BMSCs) are recognized as ideal seed cells for tissue engineering because they can stimulate osteogenesis during bone regeneration. Therefore, the aim of this study was to investigate the osteogenic potential of BMSCs derived from type 2 diabetic rats and the pathogenic characteristics of dysfunctional BMSCs that affect osteogenesis. BMSCs were isolated from normal and high-fat diet+streptozotocin-induced type 2 diabetic rats. Cell metabolic activity, alkaline phosphatase (ALP) activity, mineralization and osteogenic gene expression were reduced in the type 2 diabetic rat BMSCs. The expression levels of Wnt signaling genes, such as ß-catenin, cyclin D1 and c-myc, were also significantly decreased in the type 2 diabetic rat BMSCs, but the expression of GSK3ß remained unchanged. The derived BMSCs were cultured on calcium phosphate cement (CPC) scaffolds and placed subcutaneously into nude mice for eight weeks; they were detected at a low level in newly formed bone. The osteogenic potential of the type 2 diabetic rat BMSCs was not impaired by the culture environment, but it was impaired by inhibition of the Wnt signaling pathway, likely due to an insufficient accumulation of ß-catenin rather than because of GSK3ß stimulation. Using BMSCs derived from diabetic subjects could offer an alternative method of regenerating bone together with the use of supplementary growth factors to stimulate the Wnt signaling pathway.

The influence of obturators on the respiration of patients with maxillary defects: a clinical study.

The study evaluated the effects of obturators on respiratory function by analyzing the changes in nasal anatomic structures and physiologic function in maxillectomy patients with and without obturators. Twenty-six patients who underwent maxillectomy were chosen and rehabilitated with obturators by a single maxillofacial prosthodontist. The geometric shape of the nasal cavity, the nasal airway resistance, and the ratio of residual volume to total lung capacity (RV/TLC) were evaluated using acoustic rhinometry, rhinomanometry, and a pulmonary function test apparatus, respectively. All patients were tested twice, with and without their obturators. The results were statistically analyzed with a paired t-test. The nasal cavities (0-7 cm to the anterior nostril) of the patients with obturators had a significantly smaller volume ([-8.92, -0.60], P = 0.027), smaller effective nasal cross-sectional area MCA2 ([-3.80, -1,81], P < 0.0001), increased airflow in the nasal cavity ([17.76, 147.39], P = 0.015), reduced nasal airway resistance ([-0.11, -0.02], P = 0.009), and reduced RV/TLC ([-5.32, -1.30], P = 0.004) compared with the patients without obturators. According to the results of this study, obturators can improve respiratory function by effectively decreasing the volume of enlarged nasal cavities as well as the nasal air resistance and volume of anatomical dead space after maxillectomy.