A comparative study of the use of digital technology in the anterior smile experience.

OBJECTIVES: this study aims to compare the clinical outcomes of traditional and digital crown extension guides in the aesthetic restoration of anterior teeth. Additionally, the study will analyze the differences in the results of various digital crown extension guides in anterior aesthetic restorations. METHODS: Sixty-two patients who required aesthetic restoration of their anterior teeth were selected for this study. The patients had a total of 230 anterior teeth and were randomly divided into three groups: a control group of 22 cases who received diagnostic wax-up with pressure film, an experimental group 1 of 20 cases who received 3D printed digital models with pressure film, and an experimental group 2 of 20 patients who received digital dual-positioning guides. The control group had a total of 84 anterior teeth, experimental group 1 had 72 anterior teeth, and experimental group 2 had 74 anterior teeth. The study compared three methods for fabricating crown extension guides: the control group used the diagnostic wax-up plus compression film method, while experimental group 1 used compression film on 3D printed models and experimental group 2 used 3D printed digital dual-positioning crown extension guides. After the crown lengthening surgery, the control group patients wore DMG resin temporary crown material for gingival contouring, while the experimental group patients wore 3D printed resin temporary crowns for the same purpose. The patients were followed up in the outpatient clinic after wearing temporary crowns for 1 month, 3 months, and 6 months, respectively. The clinical results were evaluated in terms of marginal fit, red aesthetic index, and white aesthetic index. RESULTS: Based on the statistical analysis, the experimental group required significantly fewer follow-up visits and less time for guide design and fabrication compared to the control group. Additionally, the surgical time for the experimental group was significantly shorter than that of the control group. During the postoperative period between the 1st and 3rd month, the PES index scores for the marginal gingival level, proximal, and distal mesiodistal gingival papillae of the experimental group showed a trend of superiority over those of the control group. By the 6th month, the marginal gingival level exhibited a significant difference between the experimental and control groups. The experimental group demonstrated superior results to the control group in terms of shape, contour, and volume of the teeth, color, surface texture, and transparency of the restorations, and features during the 1st and 3rd postoperative months. In the 6th month, the comparative results indicated that the experimental group continued to exhibit superior outcomes to the control group in terms of the shape, color, surface texture, and transparency of the restorations, as well as the characteristics of the teeth. Additionally, the experimental group demonstrated significantly fewer gingival alterations than the control group at 1 month, 3 months, and 6 months post-procedure, with this difference being statistically significant. Furthermore, the combination of 3D printing technology and restorative techniques was utilized, resulting in consistent patient satisfaction. CONCLUSION: Digitalisation plays an important role in anterior aesthetic restorations. The use of digital technology to manage the entire process of anterior cosmetic restorations can improve restorative results, reduce the number of follow-up appointments, shorten consultation time, and achieve better patient satisfaction.

Heterospecific eavesdropping on disturbance cues of a treefrog.

Alarm signals and cues are crucial to animal survival and vary greatly across species. Eavesdropping on heterospecific alarm signals and cues can provide eavesdroppers with information about potential threats. In addition to acoustic alarm signals, evidence has accumulated that chemical alarm cues and disturbance cues can also play a role in alerting conspecifics to potential danger in adult anurans (frogs and toads). However, there is very little known about whether disturbance cues are exploited by heterospecifics. In the present study, we conducted a binary choice experiment and a prey chemical discrimination experiment, respectively, to test the responses of a sympatric anuran species (red webbed treefrogs, Rhacophorus rhodopus) and a sympatric predator species (Chinese green tree vipers, Trimeresurus stejnegeri) to disturbance odors emitted by serrate-legged small treefrogs (Kurixalus odontotarsus). In the binary choice experiment, we found that the presence of disturbance odors did not significantly trigger the avoidance behavior of R. rhodopus. In the prey chemical discrimination experiment, compared with odors from undisturbed K. odontotarsus (control odors) and odorless control, T. stejnegeri showed a significantly higher tongue-flick rate in response to disturbance odors. This result implies that disturbance odor cues of K. odontotarsus can be exploited by eavesdropping predators to detect prey. Our study provides partial evidence for heterospecific eavesdropping on disturbance cues and has an important implication for understanding heterospecific eavesdropping on chemical cues of adult anurans.

A Flow-through Passive Sampler for Microplastics in Air.

Microplastics (MP) in air have attracted increasing attention because of their ubiquitous presence. Accurate atmospheric concentrations of MP are essential for evaluating their capacity for long-range transport and for assessing human inhalation risk. In order to sample airborne MP in locations with limited power supply, we adapted a flow-through passive sampler by placing a glass fiber filter in the inner sampling tube. To test the new sampler's performance under field conditions, two sizes of the flow-through sampler (with diameters of 20 and 10 cm) and a conventionally pumped high-volume air sampler were co-deployed on the Lhasa campus of the Institute of Tibetan Plateau Research. Accurate sampling volumes could be estimated from a relationship between wind speeds recorded outside and inside of the flow-through sampler. Atmospheric concentrations and compositions of MP that compared favorably with those obtained by active sampling indicate that the larger version of the flow-through passive sampler can provide reproducible and quantitative information on atmospheric MP at sites with limited or unreliable power supply. This capability should be useful in large-scale and high-temporal resolution air monitoring networks for MP.

Enhancing Nanofiltration Selectivity of Metal-Organic Framework Membranes via a Confined Interfacial Polymerization Strategy.

Development of well-constructed metal-organic framework (MOF) membranes can bring about breakthroughs in nanofiltration (NF) performance for water treatment applications, while the relatively loose structures and inevitable defects usually cause low rejection capacity of MOF membranes. Herein, a confined interfacial polymerization (CIP) method is showcased to synthesize polyamide (PA)-modified NF membranes with MOF nanosheets as the building blocks, yielding a stepwise transition from two-dimensional (2D) MOF membranes to polyamide NF membranes. The CIP process was regulated by adjusting the loading amount of piperazine (PIP)-grafted MOF nanosheets on substrates and the additional content of free PIP monomers distributed among the nanosheets, followed by the reaction with trimesoyl chloride in the organic phase. The prepared optimal membrane exhibited a high Na2SO4 rejection of 98.4% with a satisfactory water permeance of 37.4 L·m-2·h-1·bar-1, which could be achieved by neither the pristine 2D MOF membranes nor the PA membranes containing the MOF nanosheets as the conventional interlayer. The PA-modified MOF membrane also displayed superior stability and enhanced antifouling ability. This CIP strategy provides a novel avenue to develop efficient MOF-based NF membranes with high ion-sieving separation performance for water treatment.

The combination of sesamol and clofibric acid moieties leads to a novel potent hypolipidemic agent with antioxidant, anti-inflammatory and hepatoprotective activity.

Oxidative stress and inflammation have been considered the main factors in the liver injury of clofibrate (CF). To obtain a novel antihyperlipidemic agent with antioxidant, anti-inflammation and hepatoprotection, the combination of sesamol and clofibric acid moieties was performed and achieved sesamol-clofibrate (CF-Sesamol). CF-Sesamol showed significant hypolipidemia effects in hyperlipidemia mice induced by Triton WR 1339, reducing TG by 38.8% (P < 0.01) and TC by 35.1% (P < 0.01). CF-Sesamol also displayed an alleviating effect on hepatotoxicity. The hepatic weight and hepatic coefficient were decreased. The amelioration of liver function was observed, such as aspartate and lactate transaminases (AST and ALT), alkaline phosphatase (ALP) and total proteins (TP) levels. Liver histopathological examination showed that hepatocyte necrosis, cytoplasmic loosening, nuclear degeneration and inflammatory cell infiltration reduced obviously by treatment with CF-Sesamol. Related molecular mechanisms on hepatoprotection showed that CF-Sesamol up-regulated Nrf2 and HO-1 expression and down-regulated p-NF-κB p65 expression in hepatic tissues. CF-Sesamol has significant antioxidant and anti-inflammatory effects. Plasma antioxidant enzymes such as SOD and CAT increased, anti-lipid peroxidation product MDA decreased. The expression of TNF-α and IL-6 inflammatory cytokines in liver was significantly lower than that in the CF group. The results indicated that CF-Sesamol exerted more potent antihyperlipidemic effects and definite hepatoprotective activity partly through the Nrf2/NF-κB-mediated signaling pathway.

Microplastics in a Remote Lake Basin of the Tibetan Plateau: Impacts of Atmospheric Transport and Glacial Melting.

Plastic pollution is fast becoming one of the most pressing global issues that we currently face. Remote areas, such as the polar regions and the Tibetan Plateau, are now also exposed to microplastic contamination. However, with the impact of global warming, the transport of microplastics within the glacier-lake basins in such regions remains unclear. In this work, the Nam Co Basin in the Tibetan Plateau was selected to study the characteristics of microplastics in the rain fallout, lake water, glacial runoff, and non-glacial runoff. Fiber and films were the most common microplastic morphologies in all water samples; a higher proportion (37%) of light-weighing polypropylene and small-size (50-300 µm, ∼30%) microplastics were found in the glacial runoff. Air mass trajectory analysis showed that microplastics could be transported through the atmosphere over a distance of up to 800 km. For microplastic loading in lakes, the atmospheric fallout was estimated to be 3.3 tons during the monsoon season, whereas the contributions of glacial runoff (∼41 kg) and non-glacial runoff (∼522 kg) were relatively low. For the microplastic loading in glaciers, the atmospheric deposition was ∼500 kg/yr, and the output caused by glacial melting only accounted 8% of the total atmospheric input. All these results suggested that the dominant pathway through which microplastics enter remote mountainous lake basins is atmospheric deposition, and once deposited on glaciers, microplastics will be stored for a long time. This work provides quantitative evidence elucidating the fate of microplastics in alpine lake environments.

Porphyromonas gingivalis Inhibition of MicroRNA-205-5p Expression Modulates Proinflammatory Cytokines in Gingival Epithelial Cells.

In this study, we strived to investigate the effect of miR-205-5p on JAK/STAT signaling way induced by P. gingivalis in periodontitis. Microarray analysis was conducted to find differentially expressed miRNAs in periodontitis patients. The miRNAs related to JAK/STAT signaling way were selected via DIANA TOOLS, and the targeted mRNAs of miRNAs were predicted by TargetScan. The expression of miRNAs and mRNAs, differentially expressed in periodontitis and related to JAK/STAT signaling, was detected by qRT-PCR or western blot. The relationship between miRNAs and mRNAs was confirmed by a dual luciferase assay. MiR-205-5p was downregulated and IL6ST was upregulated in periodontitis patients' clinical samples. MiR-205-5p had target binding sites of IL6ST 3' untranslated region. QRT-PCR and western blot analysis demonstrated poor expression of miR-205-5p, while IL6ST, pJAK2, p-STAT3 were extremely upregulated in gingival epithelial cells (GECs) with P. gingivalis induction. IL6ST expression in periodontitis tissue was also increased. P. gingivalis could inhibit miR-205-5p expression to activate JAK/STAT signaling in GECs and promote the occurrence and development of periodontitis.

PLGA-PTMC-Cultured Bone Mesenchymal Stem Cell Scaffold Enhances Cartilage Regeneration in Tissue-Engineered Tracheal Transplantation.

The treatment of long-segment tracheal defect requires the transplantation of effective tracheal substitute, and the tissue-engineered trachea (TET) has been proposed as an ideal tracheal substitute. The major cause of the failure of segmental tracheal defect reconstruction by TET is airway collapse caused by the chondromalacia of TET cartilage. The key to maintain the TET structure is the regeneration of chondrocytes in cartilage, which can secrete plenty of cartilage matrices. To address the problem of the chondromalacia of TET cartilage, this study proposed an improved strategy. We designed a new cell sheet scaffold using the poly(lactic-co-glycolic acid) (PLGA) and poly(trimethylene carbonate) (PTMC) to make a porous membrane for seeding cells, and used the PLGA-PTMC cell-scaffold to pack the decellularized allogeneic trachea to construct a new type of TET. The TET was then implanted in the subcutaneous tissue for vascularization for 2 weeks. Orthotopic transplantation was then performed after implantation. The efficiency of the TET we designed was analyzed by histological examination and biomechanical analyses 4 weeks after surgery. Four weeks after surgery, both the number of chondrocytes and the amount of cartilage matrix were significantly higher than those contained in the traditional stem-cell-based TET. Besides, the coefficient of stiffness of TET was significantly larger than the traditional TET. This study provided a promising approach for the long-term functional reconstruction of long-segment tracheal defect, and the TET we designed had potential application prospects in the field of TET reconstruction.

Reproducible preparation of a stable polypyrrole-coated-silver nanoparticles decorated polypyrrole-coated-polycaprolactone-nanofiber-based cloth electrode for electrochemical sensor application.

A piece of conductive cloth has been successfully constructed from polypyrrole-coated silver nanoparticle (Ag@PPy) composites decorated on electrospun polycaprolactone (PCL) nanofibers that formed the core-shell structure of Ag@PPy/PCL@PPy via a photo-induced one-step redox reaction. The photochemical reaction method both accelerated the rate of formation of silver nanoparticles (Ag NPs) and enhanced the dispersion of Ag NPs at the surface of PCL@PPy film. The resulting Ag@PPy/PCL@PPy-based cloth was flexible enough to be cut and pasted onto a glass carbon electrode for the preparation of a biosensor. The resulting biosensor showed good electrochemical activity toward the reduction of H2O2 with low detection limit down to 1 µM (S/N = 3) and wide linear detection ranging from 0.01 mM to 3.5 mM (R(2) = 0.990). This sensor has been applied to detect the trace H2O2 residual in milk. The cloth electrode has been proved to exhibit long-term stability, high selectivity, and excellent reproducibility.

[The expression level of MMP-2 and collagen of hydroxyapatite modified titanium for keratoprosthesis in the corneal stroma of rabbits].

OBJECTIVE: To investigate the expression level of metalloproteinases-2(MMP-2) and Collagen in a hydroxyapatite surfaced-modified of three Pan type titanium keratoprosthesis after that implanted into the corneal stroma of rabbits, further evaluate its biological compatibility. METHODS: Experimental study. Twenty-four New Zealand white rabbits, 2.0-2.5 kg, were respectively divided into three groups. Surgery was performed in right eye of all animals. skirt of HA-Ti and Ti were respectively inserted into the corneal stroma of rabbit of experimental group A and group B; only a sack was made without implantation in control group C . Cornea edema and corneal neovascularization were observed at scheduled times after operation; animals were sacrificed 2, 4 and 16 weeks after operation and their cornea was removed and examined under light microscopy; the surface of skirt was observed under scanning electron microscope. RESULTS: During the study period, all skirts were stable without infected, dissolved and excluded. Different degree of cornea edema and neovascularization was revealed after surgery. MMP-2 were absent in the normal corneal matrix. The expression level of MMP-2 in group A was higher than group C at all time points (F = 6.083, P < 0.05), and was increased than group B at 4th (F = 47.074, P < 0.01), and was increased than group C at 16th weeks too (F = 6.079, P < 0.05) . Corneal organization has a large green 4 weeks type III collagen and yellow red type I collagen, 16 weeks corneal mainly for bright red when within the collagen type I, still have a small amount of collagen type III. CONCLUSIONS: Rabbit cornea implanted HA-Ti skirts cause MMP-2 activation, continuous high expression didn't cause the cornea to dissolve; Collagen -III turned into collagen-I gradually in the extracellular matrix around the skirts. Hydroxyapatite modified titanium for Keratoprosthesis promoted the corneal neovascularization and improve the interfacial bio integration of skirt and host cornea.

Soil contamination and carrying capacity across the Tibetan plateau using structural equation models.

Soil contamination is a major environmental issue worldwide. Compared with Arctic, European Alps and Rocky Mountains, the soil contamination and soil environment carrying capacity (SECC) of the Tibetan Plateau (TP) is not systematic and multidimensional. In this study, the levels, influencing factors including climate factors [(i.e., mean annual precipitation (MAP) and mean annual temperature (MAT)], socio-economic factors [(i.e., population, population density and gross domestic product (GDP)], vegetation coverage factor, soil factors [(i.e., pH, soil organic carbon (SOC), total phosphorus and total nitrogen] and topographic factors [(i.e., longitude, latitude and digital elevation model (DEM)] and carrying capacity of multiple soil contaminants [persistent organic pollutants (POPs), heavy metals (HMs) and microplastics (MPs)] was systematically studied. Results show that the spatial distribution of POPs in the eastern was higher than that in the western region, and the structural equation model (SEM) demonstrate that SOC and MAT were the key factors influencing distribution. Regarding HMs, except As, moderate and heavy pollution of the remaining elements were found in the northern and eastern TP regions, and pH and MAP were the main influencing factors. The MPs showed that the distribution of the patches was influenced by GDP and MAP. Furthermore, a higher SECC in the eastern region that gradually decreased from east to west. pH is the primary factors affecting SECC, followed by normalized difference vegetation index (NDVI). An increase of pH and NDVI by one unit is likely to make SECC scores decrease by 0.8 and increase by 0.32, respectively. Taken together, these studies provide a system, cost-effective, and quantitative framework for soil contamination and carrying capacity in the TP.

Injectable decellularized dental pulp matrix-functionalized hydrogel microspheres for endodontic regeneration.

The sufficient imitation of tissue structures and components represents an effective and promising approach for tissue engineering and regenerative medicine applications. Dental pulp disease is one of the most common oral diseases, although functional pulp regeneration remains challenging. Herein, we propose a strategy that employs hydrogel microspheres incorporated with decellularized dental pulp matrix-derived bioactive factors to simulate a pulp-specific three-dimensional (3D) microenvironment. The dental pulp microenvironment-specific microspheres constructed by this regenerative strategy exhibited favorable plasticity, biocompatibility, and biological performances. Human dental pulp stem cells (hDPSCs) cultured on the constructed microspheres exhibited enhanced pulp-formation ability in vitro. Furthermore, the hDPSCs-microcarriers achieved the regeneration of pulp-like tissue and new dentin in a semi-orthotopic model in vivo. Mechanistically, the decellularized pulp matrix-derived bioactive factors mediated the multi-directional differentiation of hDPSCs to regenerate the pulp tissue by eliciting the secretion of crucial bioactive cues. Our findings demonstrated that a 3D dental pulp-specific microenvironment facilitated by hydrogel microspheres and dental pulp-specific bioactive factors regenerated the pulp-dentin complex and could be served as a promising treatment option for dental pulp disease. STATEMENT OF SIGNIFICANCE: Injectable bioscaffolds are increasingly used for regenerative endodontic treatment. Despite their success related to their ability to load stem cells, bioactive factors, and injectability, conventional bulk bioscaffolds have drawbacks such as ischemic necrosis in the central region. Various studies have shown that ischemic necrosis in the central region can be corrected by injectable hydrogel microspheres. Unfortunately, pristine microspheres or microspheres without dental pulp-specific bioactive factor would oftentimes fail to regulate stem cells fates in dental pulp multi-directional differentiation. Our present study reported the biofabrication of dental pulp-derived decellularized matrix functionalized gelatin microspheres, which contained dental pulp-specific bioactive factors and have the potential application in endodontic regeneration.

Combination wound healing using polymer entangled porous nanoadhesive hybrids with robust ROS scavenging and angiogenesis properties.

Nanoadhesives can achieve tight wound closure by connecting biomacromolecules from both sides. However, previously developed adhesive systems suffered from suboptimal wound healing efficiency due to the lack of interparticle cohesion, sufficient reactive oxygen species (ROS)-scavenging sites, and angiogenesis consideration. Herein, we developed a polymer entangled porous nanoadhesive system to address the above challenge by synergy of three functional components. Firstly, hybrid mesoporous silica nanoparticles with highly integrated polydopamine (MS-PDA) were prepared by templated synthesis. The entangling between PVA polymer and MS-PDA contributed to much stronger cohesion between nanoparticles, which led to 75% larger adhesion strength. As confirmed by in vitro and in vivo evaluations, the highly exposed catechol groups boosted the scavenging activity of ROS (1.8-4.1 fold enhancement as compared with nonporous counterpart). Consequently, more macrophages exhibited anti-inflammatory phenotype, leading to 2-2.6 fold lower pro-inflammatory cytokine levels. Moreover, the sustained release of bioactive SiO44- by the disintegration of nanoparticles contributed to ∼3-fold higher expression of VEGF and enhanced new blood vessel formation, as well as better wound repair. This platform can provide a new paradigm for developing multifunctional nanoadhesive systems in treating skin wounds. STATEMENT OF SIGNIFICANCE: PVA polymer entangled mesoporous nanoadhesives of polydopamine (PDA)/silica hybrids with the combination of excellent wound closure effect, boosted ROS-scavenging activity, and significant angiogenesis ability were developed for improving the suboptimal skin wound healing efficiency. This strategy not only greatly advances our ability to rationally integrate repairing elements in nanoadhesives for manipulating combined processes of interfacial events during wound healing, but also offers general implications toward application of polymers to reinforce the adhesion strength in nanoadhesive systems. In addition, our findings on the impacts of pore effects mediated ROS species conversion and polymer entanglement may also trigger great interests and facilitate the development/broad application of therapeutic adhesives.

Efficacy and safety of mesenchymal stem cells in the treatment of systemic sclerosis: a systematic review and meta-analysis.

BACKGROUND: Systemic sclerosis (SSc) is an autoimmune disease with high morbidity and mortality characterized by fibrosis of the skin and internal organs. Some studies have investigated the use of stem cells to treat SSc. Herein, a systematic review and meta-analysis was conducted to determine the efficacy and safety of mesenchymal stem cells (MSCs) in the treatment of SSc. METHODS: PubMed, Embase, Cochrane Library, Web of Science, OVID, China National Knowledge Infrastructure and Wanfang databases were searched up to February 1, 2021. Literature screening, data extraction and quality assessment were conducted independently by two researchers in according to the inclusion and exclusion criteria. The discrepancies were resolved by a third researcher. RESULTS: A total of 9 studies encompassing 133 SSc patients were included in the study. Compared to the baseline after treatment with MSCs: 1. The modified Rodnan skin score (mRSS) was significantly reduced in patients with SSc (P < 0.00001). 2. MSCs decreased the number of digital ulcer, mouth handicap scale, and visual analog scale of hand pain in SSc patients (P = 0.0007 and P = 0.03, respectively). 3. No statistical differences were detected in Raynaud's condition score and Cochin hand function scale score at 6 months of MSCs therapy (P = 0.5 and P = 0.62). 4. After 12 months of follow-up, MSCs improve carbon monoxide diffusing capacity and forced vital capacity of SSc patients (P < 0.05). 5. Overall, MSCs application was safe; a few cases exhibited swelling at the injection site, diarrhea and arthralgia, which had self-recovery, and no severe adverse events occurred in the included trials. CONCLUSIONS: MSC therapy improves the degree of skin thickening, lung function, and mouth opening and relieves finger ulcers and pain in patients with SSc without severe adverse events. Thus, MSCs or MSCs combined with plasma and traditional medicine might be an effective and promising treatment of SSc patients. PROSPERO registration number: CRD42020200350.

Climate change influence on the levels and trends of persistent organic pollutants (POPs) and chemicals of emerging Arctic concern (CEACs) in the Arctic physical environment - a review.

Climate change brings about significant changes in the physical environment in the Arctic. Increasing temperatures, sea ice retreat, slumping permafrost, changing sea ice regimes, glacial loss and changes in precipitation patterns can all affect how contaminants distribute within the Arctic environment and subsequently impact the Arctic ecosystems. In this review, we summarized observed evidence of the influence of climate change on contaminant circulation and transport among various Arctic environment media, including air, ice, snow, permafrost, fresh water and the marine environment. We have also drawn on parallel examples observed in Antarctica and the Tibetan Plateau, to broaden the discussion on how climate change may influence contaminant fate in similar cold-climate ecosystems. Significant knowledge gaps on indirect effects of climate change on contaminants in the Arctic environment, including those of extreme weather events, increase in forests fires, and enhanced human activities leading to new local contaminant emissions, have been identified. Enhanced mobilization of contaminants to marine and freshwater ecosystems has been observed as a result of climate change, but better linkages need to be made between these observed effects with subsequent exposure and accumulation of contaminants in biota. Emerging issues include those of Arctic contamination by microplastics and higher molecular weight halogenated natural products (hHNPs) and the implications of such contamination in a changing Arctic environment is explored.

Preparation and applications of cellulose-functionalized chiral stationary phases: A review.

Separation and identification of chiral enantiomers play an increasingly important role in many fields like pharmaceutical production, preparation of chemical intermediates and biochemistry. Although there are multiple methods for obtaining a single enantiomer, chiral chromatographic separation is still considered to be one of the most efficient methods. Among the numerous chiral separation materials, cellulose and its derivatives, with strong chiral recognition ability, large loading capacity and easy to functionalization, have been presented excellent enantioseparation performance, which reveals their great prospect in chiral separation. In this review, the types of cellulose derivatives, preparation of cellulose-functionalized chiral stationary phases and their application in chiral chromatographic separation in recent years were systematically summarized, and we hope to provide a useful reference for researchers working in chiral separation and inspire new discoveries in the field of cellulose-functionalized chiral separation materials.

[Biocompatible study of modified titanium skirt for keratoprosthesis].

OBJECTIVE: The research is engaged in developing an improved titanium skirt for keratoprosthesis, the aim of this study was to evaluate biocompatible of keratoprosthesis of novel design. METHODS: The pure titanium skirt for keratoprosthesis with three hands were first Sandblasted, and then bioactive hydroxyapatite coated on Sandblasted titanium for keratoprosthesis by a acid-alkali chemical treatment. A total of 18 New Zealand white rabbits and 18 alkali burned rabbit corneas were respectively divided into three groups (Group A, B and C; Group E, F and G) with simple random sampling methods. The modified titanium skirt was inserted into the corneal stroma of Group A and E, and then the control skirt was inserted into Group B and F. Group C and H did not insert skirt as surgery control. The interfacial biointegration of skirt/cornea were examined under light microscopy by HE, TEM and SEM. The transparent center was implanted to rabbit corneas with modified titanium skirt after 3 months. RESULTS: Dense hydroxyapatite coating was deposited on the Sandblasted specimens by an acid-alkali chemical treatment. The number of corneal fibroblasts increased significantly in Group A compared with Group B. The extracellular matrix deposited on the surface of modified titanium skirt was more dense and tight than that of control skirt. There was a significant difference in the shear force of skirt among groups A and B (t = 3.297, P < 0.05), E and F (t = 4.237, P < 0.05), and taking out the skirt in Group A and E were more difficulty than that in Group B and F after 3 months. The observation of the tissue sections of modified skirt inserted eyes revealed that there were cells and collagen-like fibres perpendicular to or at an angle to the rough interface and the cellular function was extremely active, in accordance with the results of TEM. Compared with healthy host tissue, skirt/cornea healing after alkali burn was impaired. CONCLUSIONS: Hydroxyapatite modified Sandblasted titanium skirt for keratoprosthesis can promote the interfacial biointegration of skirt and host cornea, no matter in healthy cornea or diseased cornea (alkali burn cornea). Hydroxyapatite coating improved the bioactivity of titanium.

Covalent organic frameworks embedded membrane via acetic-acid-catalyzed interfacial polymerization for dyes separation: Enhanced permeability and selectivity.

With the increasing demand of high water-quality, membrane filtration technologies are playing further important roles in water treatment owing to their small footprints, reduced use of chemicals and stable performances. However, the inherent permeability-selectivity trade-off is still a significant obstacle restricting the broad applications of membrane separation. Hydrophilic modification via doping nanoparticles into membranes is considered an effective solution to improve the permeability while maintaining selectivity. However, agglomeration of nanoparticles often results in inhomogeneity of the modified membranes. In this study, hybrid membranes with separated covalent organic framework (COF) particles that were uniformly embedded in the membrane surface pores were firstly fabricated via acetic-acid-catalyzed in situ synthesis. Owing to the ample hydrophilic chemical groups and tunable molecular transport channels in COFs, the modified membranes yielded almost twice higher water flux (about 200 L m-2·h-1·bar) than the pristine membranes with simultaneously enhanced rejection of water pollutants (i.e., dyes). In addition, the pure organic structure of COF improves the polymer-filler interaction of the mixed film, thereby reducing the risk of leakage. Therefore, the hybrid membranes also exhibited relatively high stability in long-term operations and different pH conditions, which makes them promising candidates in future membrane applications.

The hierarchical flower-like MoS2 nanosheets incorporated into PES mixed matrix membranes for enhanced separation performance.

Membrane fouling is an issue of concern due to the hydrophobic properties of polyethersulfone (PES) membrane when applied in water treatment. In this work, a facile hydrothermal method was utilized to synthesize hierarchical flower-like structured molybdenum disulfide nanosheets (HF-MoS2 NSs) that then incorporated into PES membranes as composite membranes. We characterized their permeability, the separation performance, the antifouling performance, and the antibacterial activity systematically. Results showed that composite membranes exhibited a better pure water flux (286 LMH/bar) at the HF-MoS2 NSs content of 0.4 wt%, which was 1.8 times higher than the control membrane. Also, composite PES membranes achieved 98.2% and 96.9% rejection of BSA and HA in comparison with the control PES membrane (87.3%, and 84.5%, respectively). Compare to the control PES membrane, the flux recovery ratio of the composite membrane increased from 69% to 88% for BSA fouling and increased from 84% to 93% for HA fouling. The retention rate for the organic dyes also improved slightly after HF-MoS2 NSs incorporation into the membrane. Additionally, the composite membranes exhibited a relatively high antibacterial activity against E. coli and B. subtilis with antibacterial rates of 67.8% and 82.5%, respectively. In conclusion, HF-MoS2 NSs incorporated composite membranes were shown to have outstanding filtration performance and could be a promising candidate for practical application in water filtration.

Improvement of cytocompatibility of electrospinning PLLA microfibers by blending PVP.

In this study, microfiber films were used as scaffolds for the purpose of vascular tissue engineering. The microfiber films were prepared by electrospinning of poly (l-lactide) (PLLA) and polyvinyl pyrrolidone (PVP). PLLA and PVP with different ratios were blended with dichloromethane as a spinning solvent at room temperature. The properties of the composite microfiber films were investigated by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and contact angle measurement. The SEM images showed that the morphology of the microfiber films was mainly affected by the weight ratios of PLLA/PVP. The DSC results demonstrated that PLLA and PVP mixed uniformly. And the hydrophilicity of the films measured increased along with the decrease of the PLLA/PVP ratio. Vascular smooth muscle cells (VSMCs) were used to test the cytocompatibility. Cell morphology and cell proliferation were measured by SEM, laser scanning confocal microscopy (LSCM) and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay after 2, 4, 6 days of culture. The results indicated that the cell morphology and proliferation on the composite films were better than that on the pure PLLA film. Furthermore, morphology and proliferation of VSMCs became better with decreasing of the weight ratio of PLLA/PVP. In addition, adhesion of platelet on the films was observed by SEM. The SEM images showed that the number of adhered platelets decreased with increment of PVP content in the films. The electrospinning microfiber composite films of PLLA and PVP would have potential use as the scaffolds for vascular tissue engineering.