Cytocompatibility of Ti-xZr alloys as dental implant materials.

Ti-xZr (x = 5, 15, 25, 35, 45% wt%) alloys with low elastic modulus and high mechanical strength were fabricated as a novel implant material. The biocompatibility of the Ti-xZr alloys was evaluated by osteoblast-like cell line (MG63) in terms of cytotoxicity, proliferation, adhesion, and osteogenic induction using CCK-8 and live/dead cell assays, electron microscopy, and real-time PCR. The Ti-xZr alloys were non-toxic and showed superior biomechanics compared to commercially pure titanium (cpTi). Ti-45Zr had the optimum strength/elastic modulus ratio and osteogenic activity, thus is a promising to used as dental implants.

Global trends in incidence of caries in permanent teeth of children aged 5 through 14 years, 1990 through 2019.

BACKGROUND: School-aged children are in the stage of permanent tooth eruption to replace primary teeth and this can be reached at a life stage when their health habits are being formed due to a large amount of time in school. However, data on the global trend in incidence of caries in permanent teeth in school-aged children are sparse. This study aimed to assess the trends in incidence of caries in permanent teeth in children aged 5 through 14 years from 1990 through 2019 at the global, regional, and national levels. METHODS: The authors collected data on incidence of caries in permanent teeth in children aged 5 through 14 years from 1990 through 2019 from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) to assess trends at the global, regional, and national levels. RESULTS: Globally, incident cases of caries in permanent teeth in children aged 5 through 14 years increased by 15.25% from 1990 through 2019, and the incidence rate remained stable during this period, with incidence rates of 34.04% in 1990 and 33.93% in 2019. The incidence rate increased at an average annual percentage change of 0.08% (95% CI, 0.06% to 0.10%) and 0.07% (95% CI, 0.05% to 0.09%) from 1990 through 2019 in low and low-middle sociodemographic index regions, respectively. An increasing trend also was observed in nearly one-half of GBD regions and more than one-half of the world's countries from 1990 through 2019 (P < .05). CONCLUSIONS: Global incidence of caries in permanent teeth remained stable at a high level in children aged 5 through 14 years, but there was a trend toward increasing rates in nearly one-half of sociodemographic index or GBD regions and more than one-half of the world's countries and territories from 1990 through 2019. These findings suggest that caries in permanent teeth is a priority health issue in school-aged children worldwide. PRACTICAL IMPLICATIONS: Reducing free sugar intake and implementing school-based effective caries prevention programs, such as school water fluoridation, provision of fluoride tablets at school, and school dental sealant programs, are needed for school-aged children.

Association between inequalities in human resources for health and all cause and cause specific mortality in 172 countries and territories, 1990-2019: observational study.

OBJECTIVE: To explore inequalities in human resources for health (HRH) in relation to all cause and cause specific mortality globally in 1990-2019. DESIGN: Observational study. SETTING: 172 countries and territories. DATA SOURCES: Databases of the Global Burden of Disease Study 2019, United Nations Statistics, and Our World in Data. MAIN OUTCOME MEASURES: The main outcome was age standardized all cause mortality per 100 000 population in relation to HRH density per 10 000 population, and secondary outcome was age standardized cause specific mortality. The Lorenz curve and the concentration index (CCI) were used to assess trends and inequalities in HRH. RESULTS: Globally, the total HRH density per 10 000 population increased, from 56.0 in 1990 to 142.5 in 2019, whereas age standardized all cause mortality per 100 000 population decreased, from 995.5 in 1990 to 743.8 in 2019. The Lorenz curve lay below the equality line and CCI was 0.43 (P<0.05), indicating that the health workforce was more concentrated among countries and territories ranked high on the human development index. The CCI for HRH was stable, at about 0.42-0.43 between 1990 and 2001 and continued to decline (narrowed inequality), from 0.43 in 2001 to 0.38 in 2019 (P<0.001). In the multivariable generalized estimating equation model, a negative association was found between total HRH level and all cause mortality, with the highest levels of HRH as reference (low: incidence risk ratio 1.15, 95% confidence interval 1.00 to 1.32; middle: 1.14, 1.01 to 1.29; high: 1.18, 1.08 to 1.28). A negative association between total HRH density and mortality rate was more pronounced for some types of cause specific mortality, including neglected tropical diseases and malaria, enteric infections, maternal and neonatal disorders, and diabetes and kidney diseases. The risk of death was more likely to be higher in people from countries and territories with a lower density of doctors, dentistry staff, pharmaceutical staff, aides and emergency medical workers, optometrists, psychologists, personal care workers, physiotherapists, and radiographers. CONCLUSIONS: Inequalities in HRH have been decreasing over the past 30 years globally but persist. All cause mortality and most types of cause specific mortality were relatively higher in countries and territories with a limited health workforce, especially for several specific HRH types among priority diseases. The findings highlight the importance of strengthening political commitment to develop equity oriented health workforce policies, expanding health financing, and implementing targeted measures to reduce deaths related to inadequate HRH to achieve universal health coverage by 2030.

The Expression of miR-34a in Gingival Crevicular Fluid of Chronic Periodontitis and Its Connection with the TLR/NF-κB Signaling Pathway.

Objective: This study analyzed the expression of miR-34a in gingival crevicular fluid (GCF) of patients with chronic periodontitis and its connection with the Toll-like receptor (TLR)/nuclear factor kappa-B (NF-κB) signaling pathway. Methods: We collected the GCF of the two groups of subjects, using RT-PCR to detect the expression of miR-34a and NF-κB p65 mRNA and TLR4 mRNA and ELISA to detect the inflammatory factor degree in GCF, and performed periodontal examinations on both groups. Results: The gingival index, bleeding index, probe depth, and attachment loss indexes of periodontal examination in the observation group were remarkably superior to those in the control group (P < 0.05). The levels of IL-1ß, IL-6, and TNF-α in the GCF of the observation group were higher than those of the control group (P < 0.05). The mRNA relative expression levels of miR-34a, NF-κB p65, and TLR4 in the GCF of the observation group were dramatically higher than those of the control group (P < 0.05). Correlation analysis showed that miR-34a was highly expressed in patients with chronic periodontitis. Conclusion: There is an abnormally high expression of miR-34a in GCF of chronic periodontitis. Its expression is associated with the degree of periodontal inflammation, periodontal tissue damage, and the activation of the TLR/NF-κB signaling pathway and could be used as a potential index for auxiliary diagnosis and severity of the disease.

Inhibition of circular RNA circ_0138959 alleviates pyroptosis of human gingival fibroblasts via the microRNA-527/caspase-5 axis.

Circular RNA (circRNA) plays a regulatory role in periodontitis. This study explored whether circ_0138959 affected lipopolysaccharide (LPS)-induced pyroptosis in human gingival fibroblasts (HGFs). The periodontal ligament (PDL) tissues and HGFs were derived from patients with periodontitis and healthy volunteers. HGFs treated with LPS were considered to mimic periodontitis in vitro. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to evaluate the mRNA expression levels of circRNAs, miR-527, and caspase-5 (CASP5), and Western blotting assay was used to measure protein expression levels of caspase-1, caspase-4, and cleaved N-terminal gasdermin D (GSDMD-N). Cell viability was evaluated by cell counting kit-8 (CCK-8) assay. The concentration of lactate dehydrogenase (LDH), interleukin (IL)-1ß, and IL-18 and the pyroptosis rate were determined to evaluate pyroptosis. The interaction between miR-527 and circ_0138959 or CASP5 was verified by dual-luciferase reporter and RNA pull-down assays. Circ_0138959 expression was higher in the PDL tissues of patients with periodontitis than in the healthy group; likewise, circ_0138959 was also upregulated in LPS-treated HGFs. Suppressed circ_0138959 increased cell viability and decreased pyroptosis of HGFs induced by LPS. miR-527 was a target of circ_0138959, and inhibition of miR-527 contributed to the dysfunction of LPS-treated HGFs and reversed the protective effects of downregulated circ_0138959. Additionally, miR-527 targeted CASP5. Increased CASP5 abrogated the effects of overexpressed miR-527 on cell viability and pyroptosis of LPS-treated HGFs. Inhibition of circ_0138959 promoted cell viability and suppressed pyroptosis of HGFs via the miR-527/CASP5 axis. Therefore, knockdown of circ_0138959 may be a promising therapy for periodontitis.

Computed Tomography Three-Dimensional Reconstruction Algorithm in the Diagnosis of Periodontitis and Its Correlation with Hypertension.

This study was aimed at exploring the value of iterative reconstruction (IR) algorithm to treat the periodontitis using computed tomography (CT) image and analyze the relationship between periodontitis and hypertension. 95 patients with periodontitis were selected, including 43 patients with periodontitis, 41 patients with advanced periodontitis and hypertension, and 11 patients with periodontitis and nonhigh blood pressure (NBP). The IR algorithm was introduced to the CT image scanning of them to reduce the noise. In addition, the CT value was statistically analyzed. High-sensitivity C-reactive protein (hs-CRP) and interleukin 6 (IL-6) were dramatically increased compared with periodontitis patients with NBP and with hypertension (P < 0.05). After the IR algorithm of the image, the quality, information, and mean square error (MSE) of the image were all effectively improved. Image with a 50% dose showed the lowest noise, but the reconstruction algorithm improved the low-contrast resolution. Moderate and severe periodontitis was independently related to hypertension. Inflammatory cytokines were independently related to hypertension of periodontitis patients (P < 0.05). Therefore, it was concluded that the IR algorithm could effectively improve the spatial resolution of the CT image when it was adopted to treat periodontitis and showed a high accuracy rate; the incidence of hypertension in patients with periodontitis was relatively high, and it had a certain relationship with periodontitis; and inflammatory cytokines were related to periodontitis and hypertension of patients.

Fabrication of multilevel porous structure networks on Nb-Ta-Ti alloy scaffolds and the effects of surface characteristics on behaviors of MC3T3-E1 cells.

Porous Nb-25Ta-25Ti alloys (60% porosity and 100-600 µm pore size) for bone implant applications were manufactured combining impregnation and sintering methods. Surfaces with porous micro-nanostructured networks on Nb-Ta-Ti alloys were successfully modified by various surface pre-treatments (acid etching, alkali-heat treatment and annealing treatment). Surface characteristics and Ca-P layer deposition behaviors of the multilevel structured porous Nb-Ta-Ti alloys were investigated by conducting various tests, including x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray, atomic force microscopy and optical contact angle measurement. In particular, bulk Nb-Ta-Ti alloys were also used as mutual control. The results demonstrated that the porous alloy exhibited a unique multilevel porous structure with macro-networks and micro-pits after pre-treatments. The surface passive TiO2/Nb2O5/Ta2O5layers on Nb-Ta-Ti alloys were partially dissolved by the corrosive attack of hydroxyl ions during alkali heat treatment. In addition, subsequent annealing treatment increased the density of the gel layers formed during alkali heat treatment. After immersion in SBF for 14 d, a continuous relatively uniform apatite layer was formed on the multilevel structured surfaces. Moreover, the mechanism of surface mineralization can be construed as electrostatic interactions between substrates and ions. Furthermore,in vitrocell culture showed that Nb-Ta-Ti alloys had a good biocompatibility and the multilevel porous structure could enhance the cellular behaviors including: cell adhesion and spreading.

Prevalence of toothache in Chinese adults aged 65 years and above.

OBJECTIVES: To investigate the prevalence of toothache and its risk indicators in the older Chinese population. METHODS: National cross-sectional survey data on 25 048 Chinese people ≥65 years in 2011, 2014 and 2018 survey year were analysed and then pooled. Chi-square test was used to examine the differences in prevalence among specific subgroups. Multivariate modified Poisson regression analyses with robust error variances were used to detect related factors and prevalence ratios (PR) were calculated. RESULTS: The prevalence of toothache was 16.3% (95% CI: 15.5%-17.1%), 12.8% (95% CI: 12.0%-13.7%) and 16.0% (95% CI: 15.3%-16.7%) in years 2011, 2014 and 2018. In the pooled multivariate Poisson regression model, factors associated with toothache were female (PR: 1.27, 95% CI: 1.18-1.37), younger age (PR: 1.84, 95% CI: 1.63-2.09), currently married and living with spouse (PR: 1.08, 95% CI: 1.01-1.15), current living in urban area (PR:1.12, 95% CI: 1.06-1.20), enough financial support (PR: 0.69, 95% CI: 0.65-0.74), having chronic disease (PR: 1.46, 95% CI: 1.35, 1.57), higher sugar intake (PR: 1.10, 95% CI: 1.03-1.17), salty flavour (PR:1.15, 95% CI: 1.07-1.23), smoking (PR: 1.14, 95% CI:1.06-1.23) or drinking (PR: 1.17, 95% CI: 1.09-1.25), with denture (PR: 1.15, 95% CI: 1.08-1.22) and higher toothbrushing frequency (PR: 1.25-1.50). CONCLUSIONS: More than one in ten older Chinese population had toothache, and it was related to age, gender, socioeconomic status, behaviour and oral health status. Lifestyle interventions should be taken to avoid the occurrence of the toothache.

Influence of low modulus Co-Zr alloys surface modification on protein adsorption and MC3T3-E1, NIH3T3 and RAW264.7 cell behaviour.

Three types of Co-xZr (x = 5, 7.5, and 10 wt.%) were treated with hydroxyapatite (HA) and used as an object to investigate the effect of HA coating on the surface and biocompatibility of Co-xZr alloys. And the protein adsorption and the subsequent biological behaviour of osteoblast, fibroblast and macrophages were also investigated. The surface microstructure and wettability were assessed by scanning electron microscopy (SEM) and static angle profilometer. To evaluate the biocompatibility of Co-xZr and Co-xZr-HA, we quantified plasma proteins adsorption by bicinchoninic acid assay (BCA), cytotoxicity and cell proliferation by cell counting kit-8 (CCK-8) and scanning electron microscopy (SEM). The results indicated that Co-xZr-HA alloy surfaces were more hydrophilic and had higher affinity to plasma proteins. Higher protein concentrations were found adsorbed onto Co-7.5Zr-HA and Co-10Zr-HA alloys. Cytotoxicity analysis indicated that HA coating improved the biocompatibility of Co-xZr alloys. Furthermore, the comparable results of co-incubation of Co-xZr-HA alloys with cells reveal cellular attachments to HA surfaces. HA was successfully formed on Co-xZr alloys and modified the surface structure and biocompatibility of the alloys. Co-10Zr-HA and Co-7.5Zr-HA had the most favourable properties and cytocompatibility, and therefore can be potentially used for dental implants.

Cytocompatibility, stability and osteogenic activity of powder metallurgy Ta-xZr alloys as dental implant materials.

Tantalum (Ta) and zirconium (Zr) alloys were found to had low elastic modulus and similar biomechanical characteristics as the human bone. However, the biocompatibility and osteogenic potential of Ta-xZr alloyswith different proportions (20, 30, 40 and 50% Zr by atom) remains to be investigated. In this study, the biocompatibility of Ta-xZr alloys and commercially pure titanium (cpTi) was evaluated in vitro by cell counting kit-8 assay. The adhesion of MG63 osteoblasts to the surface of the alloys was observed by fluorescence microscopy, and their morphology was analyzed by scanning electron microscopy (SEM). The expressions of alkaline phosphatase (ALP), Ki67, osteocalcin (OC), collagen-I (Col-I) and Integrin ß1 mRNA in the cultured cells were determined by RT-PCR. As a result, Ta-xZr (x = 20, 30, 40 and 50 at%) alloys were non-toxic and supported proliferation of the MG63 cells. The osteoblasts adhered to the Ta-xZr alloys, and subsequently spread and proliferated rapidly. Furthermore, the cells grown on Ta-20Zr and Ta-30Zr expressed high levels of ALP, Col I and OC, indicating that the Ta-xZr alloys can induce osteogenesis. In conclusion, Ta-xZr alloys promoted the adhesion, proliferation and osteogenic differentiation of MG63 cells. The Ta-xZr composites with a higher proportion of Ta exhibited superior osteogenic activity, and Ta-30Zr is therefore a promising alternative for Ti implants.

Evaluation of biocompatibility and osseointegration of Nb-xTi-Zr alloys for use as dental implant materials.

The aim of this study was to evaluate the biocompatibility and osteogenic potential of 50%Nb-xTi-Zr (NTZ,x= 20%, 30%, 40% by weight) alloys as compared with dental commercial pure titanium (cpTi). Cell cytotoxicity assay, fluorescence microscopy and electron microscopy were used to measure thein vitrobiocompatibility of NTZ. The expression of alkaline phosphatase (ALP), integrin ß1, osteocalcin (OC), Ki67 and collagen-I (Col-I) at the mRNA level was measured by real-time reverse transcription-polymerase chain reaction. Osseointegration ability was determined using x-ray evaluation and histological analysisin vivo. Compared with the MG63 cells grown on cpTi on day 3, the viability, adherence and proliferation rates of cells cultured on NTZ alloys were significantly improved (p< 0.05). Furthermore, similar expression levels of Ki67, Col-I, OC and ALP were found in the MG63 cells grown on NTZ alloys and those grown on cpTi. The Cbfα1 level was significantly higher for the 50%Nb-30%Ti-Zr (NTZ3) than for the cpTi group on day 6 (p< 0.01), indicating that NTZ alloys can induce osteogenesis. A considerable amount of new bone formation and osseointegration was observed around NTZ3 implants compared with cpTi implantsin vivo. Collectively, NTZ3 showed superior biocompatibility and osteogenic activity; therefore, NTZ3 may be an excellent replacement for dental Ti implants.

Recyclable deep eutectic solvent coupling sodium hydroxide post-treatment for boosting woody/herbaceous biomass conversion at mild condition.

A novel recyclable deep eutectic solvent (DES) consisting of p-toluene sulfonic acid (p-TsOH) and choline chloride (ChCl) was developed for efficient woody poplar sawdust (PL) and herbaceous miscanthus (MC) conversion at mild condition. The extraction of leftover lignin on the surface of DES pretreated residues using NaOH solution at room temperature greatly improved the enzymatic hydrolysis efficiency. Near complete cellulose conversion of PL and MC residues were obtained with a degree of delignification and xylan removal over 90% at 100 °C within 40 min. The strong correlations between xylan (R2 = 0.95) and lignin (R2 = 0.82) removal with cellulose conversion were observed in MC as well as positive correlations (R2 > 0.77) in PL. The results demonstrated that the DES system coupling NaOH post-treatment was a promising method to achieve an economically feasible biomass conversion process, which was effective for both woody PL residues and herbaceous MC.

Effects of alloying elements and annealing treatment on the microstructure and mechanical properties of Nb-Ta-Ti alloys fabricated by partial diffusion for biomedical applications.

Powder metallurgical (PM) Nb-25Ta-xTi alloys (x = 5, 15, 25, 35 at.%) were fabricated by the elemental powder sintering technology. Effects of alloying elements and annealing treatment on the microstructural evolution and mechanical properties were investigated by conducting various tests, including X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalyses (EPMA), electron back scattered diffraction detector (EBSD), transmission electron microscopy (TEM) and tensile tests. The results indicated that the alloys showed a unique Nb-rich and Ta-rich dual structure due to the insufficient diffusion between powders. With the increase of Ti content, the ß phase was always retained and the alloys exhibited a relatively high density in the range of 82.4% to 90.5%. Furthermore, owing to a higher diffusion coefficient of Ti and the strengthening effect of solid solution, the volume shrinkage and tensile strength both increased along with the increase of Ti content. After the annealing treatment was introduced, the microstructure became more homogeneous and fine equiaxed grains appeared, which induced a decrease in modulus and better ductility. The Nb-25Ta-25Ti alloys exhibited a good in vitro biocompatibility due to the chemical components and the introduce of surface pores. The PM Nb-Ta-Ti alloys were promising for biomedical applications in tissue engineering after evaluated both mechanical properties and in vitro biocompatibility.

In vitro cell response and in vivo primary osteointegration of highly porous Ta-Nb alloys as implant materials.

By combining the biocompatibility of Ta and excellent performance of Nb, the ß-type Ta-xNb (x = 5, 10, and 15 wt %) alloys with three-dimensional network structure was successfully fabricated. This work was designed to carry out the systematic study of in vitro/vivo biocompatibility of highly porous Ta-Nb alloys. In the present study, the in vitro biological response was characterized by cell attachment, cytotoxicity test, and gene expression. Cells were well distributed on porous alloy surface and both bulk/porous Ta-15Nb alloys showd a 0-1 RGR level. Moreover, the upregulated gene expression may reveal an increase in bone regeneration. An assessment of primary osteogenic response in vivo was achieved by histological evaluation and pull-out test. In vivo results demonstrated that the porous Ta-15Nb alloy showed a higher pull-out force than bulk Ta-15Nb alloy and exhibited a more extensive contact between implants and bones after 12 weeks. Based on the present experiments, porous Ta-Nb alloy scaffolds had a good biocompatibility and were promising for biomedical applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 573-581, 2019.

Microstructure, mechanical properties, and preliminary biocompatibility evaluation of binary Ti-Zr alloys for dental application.

The microstructure, mechanical properties, and in vitro biocompatibility of vacuum-sintered Ti-xZr binary alloys (x = 5, 15, 25, 35, 45 wt%) were investigated. The results indicated that α and α' phase existed in Ti-xZr alloys. The hardness of the Ti-Zr alloys increased as the contents increased and ranged from 473 HV (Ti-5Zr) to 525 HV (Ti-45Zr). Increasing Zr content could lead to an increase in compressive and bending strength. Additionally, the Ti-45Zr alloy exhibited the maximum bending strength of 867.1 MPa and the maximum compressive strength of 1599.8 MPa which were much larger than that of CP-Ti. Moreover, all Ti-Zr alloys showed a lower elastic modulus (ranging from 53.5 to 59.3 GPa) compared with CP-Ti (103 GPa). The in vitro cytotoxicity tests were carried out for biocompatibility evaluation. The alloys presented no cytotoxic effects and the surface of the alloys exhibited great growth conditions for MG-63 cells. The Ti-45Zr alloy exhibited better mechanical properties and biocompatibility. In conclusion, Ti-45Zr alloy is of great potential for dental applications.

[Evaluation of osseointegration of domestic porous tantalum-niobium alloy].

PURPOSE: To evaluate the osseointegration of domestic porous tantalum-niobium(PTa-Nb) alloy. METHODS: A total of 36 adult New Zealand rabbits were selected and divided into 3 groups. Pta-Nb rods(3.5 mm×10 mm) were implanted into the femoral condyle of each rabbit.The rabbits were sacrificed successively at 4,8,12 weeks after operation. X-ray, hard tissue slices stained with toluidine blue, scanning electron microscope(SEM), X-ray energy disperse spectroscopy(XEDS) and push-out test were used to test the osseointegration of PTa-Nb. SPSS19.0 software package was used for statistical analysis. RESULTS: X-ray films showed no obvious inflammation,as well as implants loosing and bone resorption. Density of the bone around implants increased. Hard tissue slices displayed chimeric shape in the implant-bone interface. New bone contacted directly to the surface of PTa-Nb and got more and more closer with the increase of healing time. Osteoid formed in the inner pores at 4 weeks after operation,and more mature bone tissue grew into inner part of PTa-Nb at 12 weeks. SEM showed bone tissue was more denser and closer to the Pta-Nb,which was similar to the results of hard tissue slices. XEDS analysis showed the percent content of the calcium and phosphate of the tissue within PTa-Nb increased gradually in the three groups.The ratio of Ca/P at 8 and 12 weeks was significantly higher than at 4 weeks (P<0.05); Push-out test showed the shear-strength of PTa-Nb implants increased from (8.26±0.75) MPa at 4 weeks to (21.04±1.46) MPa at 12 weeks (P<0.05). CONCLUSIONS: The domestic PTa-Nb alloy has good osseointegration with both bone tissue ongrowth and ingrowth,which may be a high potential biomimetic bone material.

Porous Nb-Ti-Ta alloy scaffolds for bone tissue engineering: Fabrication, mechanical properties and in vitro/vivo biocompatibility.

Porous Nb-Ti-Ta (at.%) alloys with the pore size of 100-600µm and the porosity of 50%-80% were fabricated by the combination of the sponge impregnation technique and sintering method. The results revealed that the pores were well connected with three-dimensional (3D) network structure, which showed morphological similarity to the anisotropic porous structure of human bones. The results also showed that the alloys could provide the compressive Young's modulus of 0.11±0.01GPa to 2.08±0.09GPa and the strength of 17.45±2.76MPa to 121.67±1.76MPa at different level of porosity, indicating that the mechanical properties of the alloys are similar to those of human bones. Pore structure on the compressive properties was also discussed on the basis of the deformation mode. The relationship between compressive properties and porosity was well consistent with the Gibson-Ashby model. The mechanical properties could be tailored to match different requirements of the human bones. Moreover, the alloys had good biocompatibility due to the porous structure with higher surface, which were suitable for apatite formation and cell adhesion. In conclusion, the porous Nb-Ti-Ta alloy is potentially useful in the hard tissue implants for the appropriate mechanical properties as well as the good biocompatible properties.

Microstructure, mechanical behavior and biocompatibility of powder metallurgy Nb-Ti-Ta alloys as biomedical material.

Microstructures, mechanical properties, apatite-forming ability and in vitro experiments were studied for Nb-25Ti-xTa (x=10, 15, 20, 25, 35at.%) alloys fabricated by powder metallurgy. It is confirmed that the alloys could achieve a relative density over 80%. Meanwhile, the increase in Ta content enhances the tensile strength, elastic modulus and hardness of the as-sintered alloys. When increasing the sintering temperatures, the microstructure became more homogeneous for ß phase, resulting in a decrease in the modulus and strength. Moreover, the alloys showed a good biocompatibility due to the absence of cytotoxic elements, and were suitable for apatite formation and cell adhesion. In conclusion, Nb-25Ti-xTa alloys are potentially useful in biomedical applications with their mechanical and biological properties being evaluated in this work.

Negative Regulation of Hepatic Inflammation by the Soluble Resistance-Related Calcium-Binding Protein via Signal Transducer and Activator of Transcription 3.

Host immune response is tightly controlled by negative regulators to avoid excessive immune reactions for homeostasis. Some pathogens may take advantage of host negative regulating system to evade host defense. Our previous report showed that foot-and-mouth disease virus (FMDV) VP1 inhibited TNF-α- and SeV-induced type I interferon response via interaction with cellular protein soluble resistance-related calcium-binding protein (sorcin). Conversely, TNF-α- or SeV-induced type I interferon response increased when sorcin knocked down, leading to inhibition of vesicular stomatitis virus replication. However, the exact role of sorcin in regulation of the immune response is still not clear. Here, we show that mice deficient of sorcin (sorcin-/-) display enhanced ConA-induced hepatitis. Importantly, splenocytes from sorcin-/- mice produced more IL-2, IL-4, IL-17, and IFN-γ than that of littermate controls (sorcin+/+) in response to anti-CD3/28 stimulation. Furthermore, our data indicate that sorcin interacts with signal transducer and activator of transcription 3 (STAT3) and enhances its phosphorylation and that STAT3 acts as an immediate downstream molecule of sorcin in the negative regulation of NF-κB signaling. Thus, sorcin, in association with STAT3, negatively regulates hepatic inflammation.

Aptamer-polymer functionalized silicon nanosubstrates for enhanced recovered circulating tumor cell viability and in vitro chemosensitivity testing.

Selection of the optimal chemotherapy regimen for an individual cancer patient is challenging. The existing chemosensitivity tests are costly, time-consuming, and not amenable to wide utilization within a clinic. This limitation might be addressed by the recently proposed use of circulating tumor cells (CTCs), which provide an opportunity to noninvasively monitor response to therapy. Over the past few decades, various techniques were developed to capture and recover CTCs, but these techniques were often limited by a capture and recovery performance tradeoff between high viability and high efficiency. In this work, we used anti-epithelial cell adhesion molecule coated aptamer-poly (N-isopropylacrylamide) functionalized silicon nanowire substrates to capture and release epithelial cell adhesion molecule-positive CTCs at 32°C and 4°C, respectively. Then, we applied the nuclease to digest the aptamer to release the captured CTCs (near or at the end of the polymer brush), which cannot be released by heating/cooling process. High viability and purity CTCs could be achieved by decreasing the heating/cooling cycles and enzymatic treatment rounds. Furthermore, the time-saving process is helpful to maintain the morphology and enhance vitality of the recovered CTCs and is beneficial to the subsequent cell culture in vitro. We validated the feasibility of chemosensitivity testing based on the recovered HCC827 cells using an adenosine triphosphate-tumor chemosensitivity assay, and the results suggested that our method can determine which agent and what concentration have the best chemosensitivity for the culturing recovered CTCs. So, the novel method capable of a highly effective capture and recovery of high viability CTCs will pave the way for chemosensitivity testing.