Effect of water glass treatment for zirconia and silane coupling on bond strength of resin cement.

OBJECTIVE: To evaluate the ability of the water glass treatment to penetrate zirconia and improve the bond strength of resin cement. MATERIAL AND METHODS: Water glass was applied to zirconia specimens, which were then sintered. The specimens were divided into water-glass-treated and untreated zirconia (control) groups. The surface properties of the water-glass-treated specimens were evaluated using surface roughness and electron probe micro-analyser (EPMA) analysis. A resin cement was used to evaluate the tensile bond strength, with2 and without a silane-containing primer. After 24 h in water storage at 37 °C and thermal cycling, the bond strengths were statistically evaluated with t-test, and the fracture surfaces were observed using SEM. RESULTS: The water glass treatment slightly increased the surface roughness of the zirconia specimens, and the EPMA analysis detected the water glass penetration to be 50 µm below the zirconia surface. The application of primer improved the tensile bond strength in all groups. After 24 h, the water-glass-treated zirconia exhibited a tensile strength of 24.8 ± 5.5 MPa, which was significantly higher than that of the control zirconia (17.6 ± 3.5 MPa) (p < 0.05). After thermal cycling, the water-glass-treated zirconia showed significantly higher tensile strength than the control zirconia. The fracture surface morphology was mainly an adhesive pattern, whereas resin cement residue was occasionally detected on the water-glass-treated zirconia surfaces. CONCLUSION: The water glass treatment resulted in the formation of a stable silica phase on the zirconia surface. This process enabled silane coupling to the zirconia and improved the adhesion of the resin cement.

Castaways: the Leeward Antilles endemic spider genus Papiamenta (Araneae: Pholcidae).

Ninetinae is a group of small to tiny short-legged spiders largely restricted to arid habitats. Among daddy-long-legs spiders (Pholcidae) this is by far the least diverse subfamily but this may partly be a result of inadequate collecting, poor representation in collections or scientific neglect. We build on a large recent collection of the ninetine genus Papiamenta Huber, 2000 from the Leeward Antilles and use cytochrome oxidase 1 (COI ) sequences, extensive scanning electron microscopy data, transmission electron microscopy data and karyotyping to analyse this geographically isolated and poorly known island genus. COI sequences support the split between the two morphologically distinct species on Curaçao but genetic distances between these are surprisingly low (7.4-9.8%; mean 8.6%). The type species P. levii (Gertsch, 1982) may include more than one species but COI and morphology suggest conflicting clade limits. A third species, P. bonay Huber sp. nov. is newly described from Bonaire. Our data on sperm ultrastructure and karyology are puzzling as these suggest different phylogenetic affinities of Papiamenta to other genera. Males transfer sperm as individual sperm (cleistosperm), agreeing with the putative closest relatives as suggested by molecular data, the North American genera Pholcophora and Tolteca . The sex chromosome system (X 1 X 2 X 3 Y ) of P. levii , however, is as in the South American Ninetinae genera Gertschiola and Nerudia but different from the putative closest relatives. ZooBank: urn:lsid:zoobank.org:pub:7A6A2E84-3A61-4637-AF6F-0E31A9FA79A8.

Preparation and comparison of binary and ternary inclusion complexes of aripiprazole using L-arginine/lysine and MßCD/HPßCD by using different molar ratios.

Aripiprazole (ARI), an antipsychotic having low solubility and stability. To overcome this, formation of binary and ternary using inclusion complexes of Methyl-ß-cyclodextrin (MßCD) /Hydroxy propyl beta cyclodextrin (HPßCD) and L-Arginine (ARG)/ Lysine (LYS) are analyzed by dissolution testing and phase stability study along with their complexation efficacy and solubility constants made by physical mixing. Inclusion complexes with ARG were better than LYS and prepared by solvent evaporation and lyophilization method as well. They are characterized by Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (AT-FTIR), X-ray powder diffractometry (XRD), Differential Scanning Calorimetry (DSC), Scanning electron microscopy (SEM) and Thermal gravimetric analysis (TGA). The bond shifting in AT-FTIR confirmed the molecular interactions between host and guest molecules. The SEM images also confirmed a complete change of drug morphology in case of ternary inclusion complexes prepared by lyophilization method for both the polymers. ARI: MßCD: ARG when used in the specific molar ratio of 1:1:0.27 by prepared by lyophilization method has 18 times best solubility while ARI:HPßCD:ARG was 7 times best solubility than pure drug making MßCD a better choice than HPßCD. Change in the molar ratio will cause loss of stability or solubility. Solvent evaporation gave significant level of solubility but less stability.

Loading cinnamon oil into pH-sensitive chitosan grafted mesoporous silica nanoparticles via supercritical carbon dioxide.

Stimulus-responsive mesoporous silica nanoparticles (MSNs) have displayed great potentiality for controlled-release and targeted drug delivery. In the current work, a supercritical fluid method was utilized to successfully prepare cinnamon oil loaded into chitosan grafted MSNs (CO@CS-MSNs). The influencing factors of drug loads, such as pressure, temperature, impregnation time and depressure time, were investigated. The structure of CO@CS-MSNs was demonstrated with Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscope (TEM), scanning electron microscopy (SEM), thermogravimetry (TG) as well as X-ray diffraction (XRD). The drug release assays in vitro at various pH conditions displayed that CO@CS-MSNs had an excellent pH-responsive release behavior, which confirmed that CO was loaded successfully into the CO@CS-MSNs. The findings indicated that the supercritical fluid approach is a non-destructive and efficient approach for stimulus-responsive MSNs, which is expected to further expand its application range.

Characterization of an advanced bone graft material with a nanocrystalline hydroxycarbanoapatite surface and dual phase composition.

The bone formation response of ceramic bone graft materials can be improved by modifying the material's surface and composition. A unique dual-phase ceramic bone graft material with a nanocrystalline, hydroxycarbanoapatite (HCA) surface and a calcium carbonate core (TrelCor®-Biogennix, Irvine, CA) was characterized through a variety of analytical methods. Scanning electron microscopy (SEM) of the TrelCor surface (magnification 100-100,000X) clearly demonstrated a nanosized crystalline structure covering the entire surface. The surface morphology showed a hierarchical structure that included micron-sized spherulites fully covered by plate-like nanocrystals (<60 nm in thickness). Chemical and physical characterization of the material using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy Energy Dispersive X-ray Spectroscopy (SEM-EDX) showed a surface composed of HCA. Analysis of fractured samples confirmed the dual-phase composition with the presence of a calcium carbonate core and HCA surface. An in vitro bioactivity study was conducted to evaluate whether TrelCor would form a bioactive layer when immersed in simulated body fluid. This response was compared to a known bioactive material (45S5 bioactive glass - Bioglass). Following 14-days of immersion, surface and cross-sectional analysis via SEM-EDX showed that the TrelCor material elicited a bioactive response with the formation of a bioactive layer that was qualitatively thicker than the layer that formed on Bioglass. An in vivo sheep muscle pouch model was also conducted to evaluate the ability of the material to stimulate an ectopic, cellular bone formation response. Results were compared against Bioglass and a first-generation calcium phosphate ceramic that lacked a nanocrystalline surface. Histology and histomorphometric analysis (HMA) confirmed that the TrelCor nanocrystalline HCA surface stimulated a bone formation response in muscle (avg. 11% bone area) that was significantly greater than Bioglass (3%) and the smooth surface calcium phosphate ceramic (0%).

Nanoemulsion with wine lees: a green approach.

Bioactive substances can be found in wine lees, a waste from the winemaking industry. This work developed two formulations, a nanoemulsion with coconut oil (NE-OC) and a nanoemulsion with coconut oil and 0.5% of wine lees extract (NE-OC-Ext), to investigate their effect on untreated, bleached, and bleached-colored hair. The oil-in-water (O/W) nanoemulsions were prepared with coconut oil, TweenTM 80, SpanTM 80, AristoflexTM AVC, Conserve NovaMit MFTM, wine lees extract, and deionized water. The hydration measurements were carried out using a Corneometer® CM 825 with the capacitance method. Scanning electron microscopy (SEM) was used to characterize the effect of formulations on hair fibers. Differential Thermal Analysis (DTA) was to assess the thermal stability and compatibility of wine lees and coconut oil in formulations. Compared to NE-OC, NE-OC-Ext showed a greater hydration effect on bleached-colored hair. DTA showed that NE-OC-Ext presented a smaller number of exothermic degradation events than those of NE-OC, suggesting good interaction and compatibility of the wine lees extract in this formulation. This study highlights the value of wine lees, a residue from the winemaking process, and its possibility of use as raw material for the cosmetic hair industry since it shows a greater moisturizing potential in colored hair.

Development of microfiltration membranes based on polysulfone and polyetherimide blends.

In this study, membranes blended with polysulfone (PSU) and polyetherimide (PEI) polymers in different ratios were fabricated. Their potential to remove pollutants from rivers, which are a potential drinking water source, was investigated. Scanning electron microscopy analysis revealed that the PSU membranes had a dense and homogeneous layer, whereas the addition of PEI formed a spongy substrate. The water content of the fabricated membranes varied between 5.37 and 22.42%, porosities 28.73-89.36%, contact angles 69.18-85.81%, and average pure water fluxes 257.25-375.32 L/m2 h. The blended membranes removed turbidity, chloride, alkalinity, conductivity, sulfate, iron, manganese, and total organic carbon up to 98.32, 92.28, 96.87, 90.67, 99.58, 94.63, 97.48, and 79.11%, respectively. These results show that when PEI was added to the PSU polymer, the filtration efficiency increased owing to an increase in the hydrophilicity of the membranes. Blending these two polymers enabled the optimization of membrane properties such as permeability, selectivity, and mechanical strength. In addition, membrane fabrication processes are simple and incur low costs.

A new physical and biological strategy to reduce the content of zearalenone in infected wheat kernels: the effect of cold needle perforation, microorganisms, and purified enzyme.

With the aim of reintroducing wheat grains naturally contaminated with mycotoxins into the food value chain, a decontamination strategy was developed in this study. For this purpose, in a first step, the whole wheat kernels were pre-treated using cold needle perforation. The pore size was evaluated by scanning electron microscopy and the accessibility of enzymes and microorganisms determined using fluorescent markers in the size range of enzymes (5 nm) and microorganisms (10 µm), and fluorescent microscopy. The perforated wheat grains, as well as non-perforated grains as controls, were then incubated with selected microorganisms (Bacillus megaterium Myk145 and B. licheniformis MA572) or with the enzyme ZHD518. The two bacilli strains were not able to significantly reduce the amount of zearalenone (ZEA), neither in the perforated nor in the non-perforated wheat kernels in comparison with the controls. In contrast, the enzyme ZHD518 significantly reduced the initial concentration of ZEA in the perforated and non-perforated wheat kernels in comparison with controls. Moreover, in vitro incubation of ZHD518 with ZEA showed the presence of two non-estrogenic degradation products of ZEA: hydrolysed zearalenone (HZEA) and decarboxylated hydrolysed ZEA (DHZEA). In addition, the physical pre-treatment led to a reduction in detectable mycotoxin contents in a subset of samples. Overall, this study emphasizes the promising potential of combining physical pre-treatment approaches with biological decontamination solutions in order to address the associated problem of mycotoxin contamination and food waste reduction.

Enhanced photocatalytic and electrochemical performance of hydrothermally prepared NiO-doped Co nanocomposites.

In this study, we synthesize nanostructured nickel oxide (NiO) and doped cobalt (Co) by combining nickel(II) chloride hexahydrate (NiCl2.6H2O) and sodium hydroxide (NaOH) as initial substances. We analyzed the characteristics of the product nanostructures, including their structure, optical properties, and magnetic properties, using various techniques such as x-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet absorption spectroscopy (UV-Vis), Fourier transform infrared (FTIR) spectroscopy, and vibrating sample magnetometers (VSM). The NiO nanoparticles doped with Co showed photocatalytic activity in degrading methylene blue (MB) dye in aqueous solutions. We calculated the degradation efficiencies by analyzing the UV-Vis absorption spectra at the dye's absorption wavelength of 664 nm. It was observed that the NiO-doped Co nanoparticles facilitated enhanced recombination and migration of active elements, which led to more effective degradation of organic dyes during photocatalysis. We also assessed the electrochemical properties of the materials using cyclic voltammetry (CV) and impedance spectroscopy in a 1 mol% NaOH solution. The NiO-modified electrode exhibited poor voltammogram performance due to insufficient contact between nanoparticles and the electrolyte solution. In contrast, the uncapped NiO's oxidation and reduction cyclic voltammograms displayed redox peaks at 0.36 and 0.30 V, respectively.

Binary and ternary complex formation and characterization of artemisinin with sulfobutyl ether ß-cyclodextrin and oleic acid.

Drug-resistant malaria is a global risk to the modern world. Artremisinin (ART) is one of the drugs of choice against drug-resistant (malaria) which is practically insoluble in water. The objective of our study was to improve the solubility of artemisinin (ART) via development of binary complexes of ART with sulfobutylether ß-cyclodextrins (SBE7 ß-CD), sulfobutylether ß-cyclodextrins (SBE7 ß-CD) and oleic acid (ternary complexes). These are prepared in various drugs to excipients ratios by physical mixing (PM) and solvent evaporation (SE) methods. Characterizations were achieved by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and attenuated total reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy. The aqueous-solubility in binary complexes was 12-folds enhanced than ternary complexes. Dissolution of binary and ternary complexes of artemisinin in simulated gastric fluid (pH 1.6) was found highest and 35 times higher for ternary SECx. The crystallinity of artemisinin was decreased in physical mixtures (PMs) while SECx exhibited displaced angles. The attenuated-intensity of SECx showed least peak numbers with more displaced-angles. SEM images of PMs and SECx showed reduced particle size in binary and ternary systems as compared to pure drug-particles. ATR-FTIR spectra of binary and ternary complexes revealed bonding interactions among artemisinin, SBE7 ß-CD and oleic acid.

Structure, thermal stability, physicochemical and functional characteristics of insoluble dietary fiber obtained from rice bran with steam explosion treatment: Effect of different steam pressure and particle size of rice bran.

Rice bran was modified by steam explosion (SE) treatment to investigate the impact of different steam pressure (0.4, 0.8, 1.2, 1.6, and 2.0 MPa) with rice bran through 60 mesh and rice bran pulverization (60, 80, and 100 mesh) with the steam pressure of 1.2 MPa on the structure, thermal stability, physicochemical and functional characteristics of insoluble dietary fiber (IDF) extracted from rice bran. IDF with SE treatment from scanning electron microscopy images showed a porous honeycomb structure, and lamellar shape in IDF became obvious with the increase of steam pressure. The relative crystallinity and polymerization degree of crystalline regions in IDF from rice bran with SE treatment from X-ray diffraction analysis were decreased. Differential scanning calorimetry results showed that thermal stability of IDF with SE treatment increased with the increase of crushing degree. The results of FT-IR also suggested that some glycosidic and hydrogen bonds in IDF could be broken, and some cellulose and hemicellulose were degraded during SE process. The physicochemical and functional characteristics of IDF, including water-holding capacity, oil-holding, glucose adsorption capacity, α-amylase and pancreatic lipase inhibition capacity were decreased with the increase of steam pressure and crushing degree. The swelling and nitrite adsorption capacities of IDF were increased first and then decreased with the increase of steam pressure. The physicochemical and functional characteristics of IDF from rice bran were improved after SE treatment, which might provide references for the utilization of IDF from rice bran with SE treatment.

Prophylactic efficacy of baicalin and carvacrol against Salmonella Typhimurium biofilm on food and food contact surfaces.

This study examines the antimicrobial and antibiofilm effectiveness of baicalin and carvacrol against Salmonella enterica ser. Typhimurium on food contact surfaces and chicken meat. The minimum inhibitory concentrations (MIC) for baicalin and carvacrol were found to be 100 µg/mL and 200 µg/mL, respectively, which aligns with findings from previous studies. The compounds exhibited a concentration-dependent decrease in microbial populations and biofilm formation. When used together, they displayed a remarkable synergistic effect, greatly augmenting their antibacterial activity. The assessment of food quality demonstrated that these treatments have no negative impact on the sensory characteristics of chicken meat. The impact of the structure on biofilms was observed through the use of Field Emission Scanning Electron Microscopy (FE-SEM) and Confocal Laser Scanning Microscopy (CLSM), revealing disrupted biofilm architectures and decreased cell viability. Crucially, RT-PCR analysis revealed a marked downregulation of quorum sensing (luxS), virulence (hilA), and stress response (rpoS) genes, highlighting the multifaceted antimicrobial mechanism of action. This gene-specific suppression suggests a targeted disruption of bacterial communication and virulence pathways, offering insight into the comprehensive antibiofilm strategy. This provides further insight into the molecular mechanisms that contribute to their antibiofilm effects.

Complement Cascade 8 - Alpha and Calpain-2 in Extracellular Vesicles of Human Vitreous as Biomarkers of Infectious Endophthalmitis.

Purpose: Extracellular vesicles (EVs) are messenger pigeons of the cells that communicate about cellular microenvironment. In this study, we evaluated the expression of C8α and calpain-2 in EVs from vitreous of patients with bacterial endophthalmitis to assess its utility as a diagnostic marker. Methods: EVs were isolated from vitreous of patients with bacterial endophthalmitis (culture positive and culture negative) and noninfectious control by exosome isolation reagent and characterized, and the levels of C8α and calpain-2 was assessed by enzyme-linked immunosorbent assay in isolated EVs and direct vitreous. The receiver operating characteristic curve was generated to assess the diagnostic performance. Results: Scanning electron microscopy (SEM) and dynamic light scattering (DLS) confirmed the presence of EVs having a diameter (nm) of 275.2 ± 93, 92 ± 22, and 77.28 ± 12 in culture-positive (CP), culture-negative (CN), and control respectively. The expression level (ng/mL) of C8α in the EVs obtained from CP was 144 ± 22 and CN was 31.2 ± 9.8, which was significantly higher (P < 0.01) than control 3.7 ± 2.4. Interestingly, C8α is not expressed directly in the vitreous of CN and controls. Calpain-2 was significantly downregulated (P ≤ 0.0001) in CP (0.94 ± 0.16) and CN (0.70 ± 0.14) than control. The sensitivity and specificity of 1 for C8α and calpain-2 in the EVs implied that its diagnostic accuracy was significant. Conclusions: This study showed that the EV proteins C8α and calpain-2 could be suitable diagnostic markers for endophthalmitis. However, the presence of C8α in the EVs of CN samples but not in direct vitreous promises EVs as the future of diagnostics. Translational Relevance: Expression levels of EV-calpain-2 and EV-C8α could diagnose CN bacterial endophthalmitis.

Ultrastructure of the antennal sensilla of the praying mantis Creobroter nebulosa Zheng (Mantedea: Hymenopodidae).

The praying mantis Creobroter nebulosa Zheng (Mantedea: Hymenopodidae) is an insect that has medicinal and esthetical importance, and being a natural enemy for many insects, the species is used as a biological control agent. In this publication, we used scanning electron microscopy (SEM) to study the fine morphology of antennae of males and females of this species. The antennae of both sexes are filiform and consist of three parts: scape, pedicel, and flagellum (differing in the number of segments). Based on the external morphology and the sensilla distribution, the antennal flagellum is could be divided into five regions. Seven sensilla types and eleven subtypes of sensilla were observed: grooved peg sensillum (Sgp), Bohm bristles (Bb), basiconic sensillum (Sb), trichoid sensillum (StI, StII), campaniform sensillum (Sca), chaetic sensillum (ScI, ScII, ScIII), and coeloconic sensillum (ScoI, ScoII). In Mantodea, the ScoII is observed for the first time, and it is located on the tip of the flagellum. The external structure and distribution of these sensilla are compared to those of other insects and possible functions of the antennal sensilla are discussed. The males and females of the mantis could be distinguished by the length of antennae and number of Sgp. Males have antennae about 1.5 times longer and have significantly larger number of Sgp compared to females. The sexual difference in distribution of the Sgp suggests that this type of sensilla may play a role in sex-pheromones detection in mantis.

Adhesion of Acanthamoeba on Scleral Contact Lenses According to Lens Shape.

Purpose: To investigate the adhesion of Acanthamoeba to scleral contact lens (ScCL) surface according to lens shape. Methods: Two strains of A. polyphaga (CDC:V062 and ATCC 30461) and one clinical Acanthamoeba isolate, were inoculated onto five contact lens (CL): one first-generation silicone hydrogel (SHCL; lotrafilcon B; adhesion control) containing plasma surface treatment; two ScCL (fluorosilicone acrylate) one containing surface treatment composed of plasma and the other containing plasma with Hydra-PEG, and two CL designed with a flat shape having the same material and surface treatments of the ScCL. Trophozoites that adhered to the lens's surfaces were counted by inverted optical light microscopy. Possible alterations of the lens surface that could predispose amoeba adhesion and Acanthamoeba attached to these lens surfaces were evaluated by scanning electron microscopy (SEM). Results: All strains revealed greater adhesion to the ScCL when compared with the flat lenses (P < 0.001). The clinical isolate and the ATCC 30461 had a higher adhesion (P < 0.001) when compared with the CDC:V062. A rough texture was observed on the surface of the lenses that have been examined by SEM. Also, SEM revealed that the isolates had a rounded appearance on the surface of the ScCL in contrast with an elongated appearance on the surface of the silicone hydrogel. Conclusions: The findings revealed that the curved shape of the ScCL favors amoeba adhesion.

Impact of Obesity and Age on Mouse Corneal Innervation at the Epithelial-Stromal Interface.

Purpose: The corneal epithelium is the most highly innervated structure in the body. Previously, we reported a novel event whereby stromal axons fuse with basal epithelial cells, limiting nerve penetration into the epithelium. Although corneal-epithelial nerves undergo changes in sensitivity and distribution throughout life and in response to an obesogenic diet, it is unknown if neuronal-epithelial cell fusion is altered. Here, we sought to determine if neuronal-epithelial cell fusion frequency correlates with obesogenic diet consumption and age. Methods: Corneas were collected from C57BL/6 mice and evaluated for neuronal-epithelial cell fusion frequency using serial block-face scanning electron microscopy. To assess the correlation between diet-induced obesity and fusion frequency, 6-week-old mice were fed either a normal diet or an obesogenic diet for 10 weeks. To assess changes in fusion frequency between young and adult mice under normal dietary conditions, 9- and 24-week-old mice were used. Results: Mice fed a 10-week obesogenic diet showed 87% of central-cornea stromal nerves engaged in fusion compared with only 54% in age-matched controls (16 weeks old). In 9-week-old normal-diet animals, 48% of central-cornea stromal nerves contained fusing axons and increased to 81% at 24 weeks of age. Corneal sensitivity loss correlated with increased body weight and adiposity regardless of age and diet. Conclusions: Neuronal-epithelial cell fusion positively correlates with age and obesogenic diet consumption, and corneal nerve sensitivity loss correlates with increased body weight and adiposity, regardless of age and diet. As such, neuronal-epithelial cell fusion may play a role in corneal nerve density and sensitivity regulation.

Paedodontic preformed crowns in primary teeth and relative degree of dental wear.

AIM: Prosthetic rehabilitation of deciduous teeth in paediatric age using pre-formed crowns has been considered one of the best methods of dental restoration since their introduction. Their main advantages are related to durability, longevity and a low rate of recurrent cavities. Since stainless steel crowns do not coincide with aesthetic needs of parents and patients, preformed paedodontic crowns made of zirconia and nano-hybrid composite was introduced. The aim of the study is to evaluate the degree of wear on the enamel and on themselves of the different paedodontic crowns. MATERIALS: Nine bovine teeth and nine paedodontic crowns for deciduous molars were selected for the study, three of which in zirconia, three in nano-hybrid composite and three in stainless steel. Wear test was carried out on the Rtech™ Instruments tribometer applying a force of 50 N. After that, both the bovine teeth and the paedodontic crowns were observed using a stereo microscope (Zeiss Stemi C-500) and a scanning electron microscope (SEM, Cambridge Stereoscan 440). The areas of wear were calculated with a software [ImageJ, version 1x, Wayne Rasband, Maryland, USA]. CONCLUSION: Pre-formed paediatric crowns in zirconia, nano-hybrid composite and stainless steel are a valid aid for the restoration of deciduous teeth and do not compromise the physiological wear characteristic of the phases of the dental exchange. The stainless steel crown is preferable for the restorations in the posterior sectors as its behaviour is the most similar to that of a natural tooth. Zirconia and nano-hybrid composite crowns showed an inversely proportional behaviour between their wear volume and that of the opposing tooth.

Electrospun fibers modified with polydopamine for enhancing human mesenchymal stem cell culture.

In this study, we coated electrospun polycaprolactone (PCL) fibers with polydopamine (PDA) to modify their hydrophobicity and fabricated a matrix for culturing mesenchymal stem cells (MSCs). Additionally, we incorporated Arg-Gly-Asp (RGD) peptides into PDA to enhance MSCs culture performance on PCL fibers. PDA and RGD were successfully coated in one step by immersing the electrospun fibers in a coating solution, without requiring an additional surface activation process. The characteristics of functionalized PCL fibers were analyzed by scanning electron microscopy with energy-dispersive x-ray analysis, Fourier transform infrared spectroscopy, water contact angle measurement, and fluorescence measurements using a carboxylic-modified fluorescent microsphere. MSCs cultured on the modified PCL fibers demonstrated enhanced cell adhesion, proliferation, and osteogenic- and chondrogenic differentiation. This study provides insight into potential applications for scaffold fabrication in MSCs-based tissue engineering, wound dressing, implantation, and a deeper understanding of MSCs behaviorin vitro.

Loading rutin on surfaces by the layer-by-layer assembly technique to improve the oxidation resistance and osteogenesis of titanium implants in osteoporotic rats.

The purpose of this study was to construct a rutin-controlled release system on the surface of Ti substrates and investigate its effects on osteogenesis and osseointegration on the surface of implants. The base layer, polyethylenimine (PEI), was immobilised on a titanium substrate. Then, hyaluronic acid (HA)/chitosan (CS)-rutin (RT) multilayer films were assembled on the PEI using layer-by-layer (LBL) assembly technology. We used scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and contact angle measurements to examine all Ti samples. The drug release test of rutin was also carried out to detect the slow-release performance. The osteogenic abilities of the samples were evaluated by experiments on an osteoporosis rat model and MC3T3-E1 cells. The results (SEM, FTIR and contact angle measurements) all confirmed that the PEI substrate layer and HA/CS-RT multilayer film were effectively immobilised on titanium. The drug release test revealed that a rutin controlled release mechanism had been successfully established. Furthermore, thein vitrodata revealed that osteoblasts on the coated titanium matrix had greater adhesion, proliferation, and differentiation capacity than the osteoblasts on the pure titanium surface. When MC3T3-E1 cells were exposed to H2O2-induced oxidative stressin vitro, cell-based tests revealed great tolerance and increased osteogenic potential on HA/CS-RT substrates. We also found that the HA/CS-RT coating significantly increased the new bone mass around the implant. The LBL-deposited HA/CS-RT multilayer coating on the titanium base surface established an excellent rutin-controlled release system, which significantly improved osseointegration and promoted osteogenesis under oxidative stress conditions, suggesting a new implant therapy strategy for patients with osteoporosis.

Electron Microscopy of Cryptococcus neoformans: Processing Challenges to Avoid Artifacts.

This chapter describes methodological details for preparing specimens of Cryptococcus neoformans (although it can be applied to any species of the genus) and their subsequent analysis by scanning and transmission electron microscopy. Adaptations to conventional protocols for better preservation of the sample, as well as to avoid artifacts, are presented. The protocols may be used to examine both the surface ultrastructure and the interior of this pathogenic fungus in detail.