Lipidomic changes in mouse oocytes vitrified in PEG 8000-supplemented vitrification solutions.

Cryopreserved oocytes are inevitably exposed to cold stress, which negatively affects the cellular aspects of the oocytes. Lipidomic analysis of the oocytes reveals quantitative changes in lipid classes under conditions of cold stress, leading to potential freezing-vulnerability. We had previously shown that specific phospholipids are significantly downregulated in vitrified-warmed mouse oocytes compared to those in fresh oocytes. In this study, we examined whether supplementation of polyethylene glycol 8000 (PEG 8000) during vitrification influences the lipidome of the oocytes. We used liquid chromatography with tandem mass spectrometry (LC-MS/MS) to study the alteration in the lipidome in three groups of mouse oocytes: fresh, vitrified-warmed, and vitrified with PEG 8000-warmed during vitrification. In these groups, we targeted to analyze 21 lipid classes. We profiled 132 lipid species in the oocytes and statistical analyses revealed lipid classes that were up- or downregulated in these groups. Overall, our data revealed that several classes of lipids were affected during vitrification, and that oocytes vitrified with PEG 8000 to some extent alleviated the levels of changes in phospholipid and sphingolipid contents during vitrification. These results suggest that phospholipids and sphingolipids are influenced by PEG 8000 during vitrification and that PEG 8000 can be considered as a potential candidate for preserving membrane integrity during oocyte cryopreservation.

Validation of mandibular genioplasty using a stereolithographic surgical guide: in vitro comparison with a manual measurement method based on preoperative surgical simulation.

PURPOSE: Stereolithographic guidance, increasingly used in orthognathic surgery, has not been completely verified for genioplasty. This study compared the accuracy of manual measurement with that of a stereolithographic guide in vitro. MATERIALS AND METHODS: Thirty rapid prototype (RP) mandibular models (15 pairs) were included in the experimental (stereolithographic) and control (manual) groups (15 each). Surgical simulation was performed in the 2 groups by advancing the chin 5 mm and then vertically reducing the chin 5 mm using Mimics software. In the stereolithographic group, genioplasty was performed on mandibular RP models using a 3-dimensionally printed surgical guide based on surgical simulation results. In the control group, it was performed using an osteotomy line drawn according to simulation measurements. For the 2 groups, anterior horizontal transverse error and anterior and posterior vertical errors were compared, as were data from the osteotomized chin segment and the preoperative surgical simulation. Positional difference error was calculated and the differences were evaluated with t tests. RESULTS: For advancement genioplasty, the absolute anterior transverse error value was 0.47 ± 0.35 (mean ± standard deviation) with the stereolithographic guide, less than with the manual method (0.77 ± 0.45; P = .001). For reduction genioplasty, the absolute anterior vertical error value was 0.27 ± 0.23 mm with the stereolithographic guide versus 0.58 ± 0.49 mm with the manual method (P < .001). CONCLUSION: Use of a stereolithographic surgical guide increased accuracy, but the difference in mean error values between methods was only approximately 0.3 mm. The superior accuracy may not be compelling in favor of stereolithographic surgical guides.

Bio-inspired, melanin-like nanoparticles as a highly efficient contrast agent for T1-weighted magnetic resonance imaging.

The development of nontoxic and biocompatible imaging agents will create new opportunities for potential applications in clinical MRI diagnosis. Synthetic melanin-like nanoparticles (MelNPs), analogous to natural sepia melanin (a major component of the cuttlefish ink), can be used as contrast agent for MRI. MelNPs complexed with paramagnetic Fe(3+) ions show much higher relaxivity values than existing MRI T1 contrast agents based on gadolinium (Gd) or manganese (Mn); MelNP values at 3T were r1 = 17 and r2 = 18 mM(-1) s(-1) (r2/r1 value of 1.1). With significant enhancement to MRI contrast, this biomimetic approach using MelNPs functionalized with paramagnetic Fe(3+) ions and surface-modified with biocompatible poly(ethylene glycol) units, could provide new insight into how melanin-based bioresponsive and therapeutic imaging probes integrate with their various biological functions.

Superstrong Carbon Nanotube Yarns by Developing Multiscale Bundle Structures on the Direct Spin-Line without Post-Treatment.

Super strong fibers, such as carbon or aramid fibers, have long been used as effective fillers for advanced composites. In this study, the highest tensile strength of 5.5 N tex-1 for carbon nanotube yarns (CNTYs) is achieved by controlling the micro-textural structure through a facile and eco-friendly bundle engineering process in direct spinning without any post-treatment. Inspired by the strengthening mechanism of the hierarchical fibrillary structure of natural cellulose fiber, this study develops multiscale bundle structures in CNTYs whereby secondary bundles, ≈200 nm in thickness, evolve from the assembly of elementary bundles, 30 nm in thickness, without any damage, which is a basic load-bearing element in CNTY. The excellent mechanical performance of these CNTYs makes them promising substitutes for the benchmark, lightweight, and super strong commercial fibers used for energy-saving structural materials. These findings address how the tensile strength of CNTY can be improved without additional post-treatment in the spinning process if the development of the aforementioned secondary bundles and the corresponding orientations are properly engineered.

Structural and performance variation of PES/PVDF membranes after exposure to the pretreated feed water of CECs.

In this study, the removal efficiency of chemicals of emerging concerns (CECs) was evaluated under exposure to various doses of UV/H2O2-based oxidation processes in combination with membrane filtration for three cleaning cycles. Polyethersulphone (PES) and polyvinylidene fluoride (PVDF) materials based membranes were used for this study. The chemical cleaning of the membranes was performed by immersion of the membranes into 1 N HCl followed by adding 3000 mg.L-1 NaOCl for 1hr. Degradation and filtration performance was evaluated using Liquid Chromatography with tandem mass spectrometry (LC-MS/MS) and total organic carbon (TOC) analysis. Membrane fouling analysis for assessing the comparative performance of PES and PVDF membranes was determined by specific fouling and fouling indices evaluation. Membrane characterization results show that the alkynes and carbonyl group formation are due to dehydrofluorination and oxidation of PVDF and PES membranes under the attack of foulants and cleaning chemicals, which resulted in a reduction of fluoride percentage and an increase in sulfur percentage in the PVDF and PES membranes. A decrease in the hydrophilicity of the membranes in underexposed conditions was observed and is consistent with an increase in dose. Degradation results of CECs follow with the highest removal efficiency of chlortetracycline (CTC) followed by atenolol (ATL), acetaminophen (ACT), and caffeine (CAF) degradation due to attack on the aromatic ring and the carbonyl group of CECs by OH exposure. Membrane exposed at 3 mg.L-1 dose of UV/H2O2-based CECs shows minimum alteration with higher filtration efficiency and lower fouling, particularly in PES membranes.

Mobile Point-of-Care Device Using Molecularly Imprinted Polymer-Based Chemosensors Targeting Interleukin-1ß Biomarker.

Molecularly imprinted polymers (MIPs) have garnered significant attention as a promising material for engineering specific biological receptors with superior chemical complementarity to target molecules. In this study, we present an electrochemical biosensing platform incorporating MIP films for the selective detection of the interleukin-1ß (IL-1ß) biomarker, particularly suitable for mobile point-of-care testing (POCT) applications. The IL-1ß-imprinted biosensors were composed of poly(eriochrome black T (EBT)), including an interlayer of poly(3,4-ethylene dioxythiophene) and a 4-aminothiophenol monolayer, which were electrochemically polymerized simultaneously with template proteins (i.e., IL-1ß) on custom flexible screen-printed carbon electrodes (SPCEs). The architecture of the MIP films was designed to enhance the sensor sensitivity and signal stability. This approach involved a straightforward sequential-electropolymerization process and extraction for leaving behind cavities (i.e., rebinding sites), resulting in the efficient production of MIP-based biosensors capable of molecular recognition for selective IL-1ß detection. The electrochemical behaviors were comprehensively investigated using cyclic voltammograms and electrochemical impedance spectroscopy responses to assess the imprinting effect on the MIP films formed on the SPCEs. In line with the current trend in in vitro diagnostic medical devices, our simple and effective MIP-based analytical system integrated with mobile POCT devices offers a promising route to the rapid detection of biomarkers, with particular potential for periodontitis screening.

Effects of bone cement augmentation for uppermost instrumented vertebra on adjacent disc segment degeneration in lumbar fusions.

OBJECTIVE: We investigated the long-term effects of bone cement-augmented instrumentation in multilevel lumbar fusions in a retrospective cohort study. The use of cement-augmented screws is one of the techniques used to reduce early mechanical failure in treating multilevel lumbar fusion, especially in the elderly. However, little information is available regarding the long-term effects. METHODS: A total of 51 patients who had undergone ≥3 levels of lumbar fusion were divided into two groups according to the use of bone cement-augmented screw fixation involving the upper instrumented vertebra: 22 patients in the cement-augmented group (group I) and 29 patients in the non-cement-augmented group (group II). Analysis of radiographic adjacent disc segment degeneration (ASD) revealed patients with lumbosacral fusion with a similar degree of osteoporosis. Radiologic ASD was defined as progression of >2 UCLA (University of California, Los Angeles) grades at 2 years postoperatively. Other sagittal parameters and the preoperative magnetic resonance imaging Pfirrmann grades at the adjacent levels, possibly related to ASD, were also analyzed. RESULTS: No significant differences were present in the preoperative demographic and radiographic parameters between the 2 groups. However, the postoperative kyphotic changes at 3 months were greater for the non-cement-augmented group. In terms of the long-term effects, the incidence of radiologic ASD (group I, n = 20 [95.2%]; vs group II, n = 15 [53.6%]) was significantly higher in the cement-augmented group. Logistic regression analysis of radiologic ASD, including other clinical and radiologic parameters, postoperative pelvic incidence-lumbar lordosis mismatch (odds ratio, 5.201; 95% confidence interval, 1.123-24.090; P = 0.035), and cement augmentation (odds ratio, 20.193; 95% confidence interval, 2.195-185.729; P = 0.008) showed a significant correlation with the development of radiologic ASD at 2 years postoperatively. CONCLUSIONS: Although bone cement-augmented screw implantation can prevent kyphotic deformation at the proximal junction of upper instrumented vertebra in the early postoperative stages of multilevel lumbar fusion, a careful selection of patients is required because of possibly accelerated degeneration of adjacent segments.

Effect of torrefied biomass on hydrophobicity and mechanical properties of polylactic acid composite.

In this study, the physicochemical properties of torrefied biomass (larch and yellow poplar) were investigated based on torrefaction temperature. The effect of torrefied biomass on the hydrophobicity and mechanical properties of a polylactic acid (PLA) composites was evaluated. Hemicellulose was removed from the biomass during torrefaction, whereas the cellulose and lignin contents increased slightly. The color of the biomass changed from brown to black. The grindability of the torrefied biomass improved as the torrefaction temperature increased, which contributed to the production of fine particles (>100 mesh). A PLA composite was prepared using torrefied biomass (10 %) and polylactic acid. At 280 °C, water contact angle was the highest, regardless of the particle size and biomass species. Tensile strength of the PLA composite was slightly lower than that of PLA alone, regardless of the particle size of torrefied biomass. Nevertheless, the strength increased with the torrefaction temperature, except for larch with a relatively large particle size (<100 mesh). The tensile strength of the control was 68.0 MPa, whereas that of the torrefied biomass ranged from 61.1 to 65.8 MPa.

Bias-free solar hydrogen production at 19.8 mA cm-2 using perovskite photocathode and lignocellulosic biomass.

Solar hydrogen production is one of the ultimate technologies needed to realize a carbon-neutral, sustainable society. However, an energy-intensive water oxidation half-reaction together with the poor performance of conventional inorganic photocatalysts have been big hurdles for practical solar hydrogen production. Here we present a photoelectrochemical cell with a record high photocurrent density of 19.8 mA cm-2 for hydrogen production by utilizing a high-performance organic-inorganic halide perovskite as a panchromatic absorber and lignocellulosic biomass as an alternative source of electrons working at lower potentials. In addition, value-added chemicals such as vanillin and acetovanillone are produced via the selective depolymerization of lignin in lignocellulosic biomass while cellulose remains close to intact for further utilization. This study paves the way to improve solar hydrogen productivity and simultaneously realize the effective use of lignocellulosic biomass.

Structural characterization of the lignin-carbohydrate complex in biomass pretreated with Fenton oxidation and hydrothermal treatment and consequences on enzymatic hydrolysis efficiency.

In this study, lignin-carbohydrate complexes (LCCs) were isolated from biomass (raw and pretreated) to investigate the structural changes in biomass pretreated by Fenton oxidation and hydrothermal treatment, and their effect on enzymatic hydrolysis. The composition and structure of the LCCs fractions were investigated via carbohydrate analysis, XRD, FT-IR, and 2D HSQC NMR. The biomass degradation rate of yellow poplar and larch during Fenton oxidation and hydrothermal treatment was approximately 30%. Most of the hemicellulose was degraded during pretreatment, while xylan remained in the yellow poplar, and galactan, mannan, and xylan remained in the larch. The fractional yield of glucan-rich LCC (LCC1) in the yellow poplar (raw and pretreated biomass) was high, while that of glucomannan-rich LCC (LCC3) in larch was higher than the yield yellow poplar. Phenyl glycoside, γ-ester, and benzyl ether linkages were observed in the LCCs of yellow poplar, while phenyl glycoside and γ-ester were detected in those of larch. Following pretreatment, the frequencies of ß-ß', ß-5, and γ-ester in the LCCs of larch were found to be higher than in those of yellow poplar. The efficiencies of enzymatic hydrolysis for the pretreated yellow poplar and larch were 93.53% and 26.23%, respectively. These finding indicated that the ß-ß', ß-5, and γ-ester linkages included in the pretreated biomass affected the efficiency of enzymatic hydrolysis.

Complete and efficient conversion of plant cell wall hemicellulose into high-value bioproducts by engineered yeast.

Plant cell wall hydrolysates contain not only sugars but also substantial amounts of acetate, a fermentation inhibitor that hinders bioconversion of lignocellulose. Despite the toxic and non-consumable nature of acetate during glucose metabolism, we demonstrate that acetate can be rapidly co-consumed with xylose by engineered Saccharomyces cerevisiae. The co-consumption leads to a metabolic re-configuration that boosts the synthesis of acetyl-CoA derived bioproducts, including triacetic acid lactone (TAL) and vitamin A, in engineered strains. Notably, by co-feeding xylose and acetate, an enginered strain produces 23.91 g/L TAL with a productivity of 0.29 g/L/h in bioreactor fermentation. This strain also completely converts a hemicellulose hydrolysate of switchgrass into 3.55 g/L TAL. These findings establish a versatile strategy that not only transforms an inhibitor into a valuable substrate but also expands the capacity of acetyl-CoA supply in S. cerevisiae for efficient bioconversion of cellulosic biomass.

On/off switchable physical stimuli regulate the future direction of adherent cellular fate.

The utilization of cell-manipulating techniques reveals information about biological behaviors suited to address a wide range of questions in the field of life sciences. Here, we introduced an on/off switchable physical stimuli technique that offers precise stimuli for reversible cell patterning to allow regulation of the future direction of adherent cellular behavior by leveraging enzymatically degradable alginate hydrogels with defined chemistry and topography. As a proof of concept, targeted muscle cells adherent to TCP exhibited a reshaped structure when the hydrogel-based physical stimuli were applied. This simple tool offers easy manipulation of adherent cells to reshape their morphology and to influence future direction depending on the characteristics of the hydrogel without limitations of time and space. The findings from this study are broadly applicable to investigations into the relationships between cells and physiological extracellular matrix environments as well as has potential to open new horizons for regenerative medicine with manipulated cells.

Survival analysis of orthodontic mini-implants.

INTRODUCTION: Survival analysis is useful in clinical research because it focuses on comparing the survival distributions and the identification of risk factors. Our aim in this study was to investigate the survival characteristics and risk factors of orthodontic mini-implants with survival analyses. METHODS: One hundred forty-one orthodontic patients (treated from October 1, 2000, to November 29, 2007) were included in this survival study. A total of 260 orthodontic mini-implants that had sandblasted (large grit) and acid-etched screw parts were placed between the maxillary second premolar and the first molar. Failures of the implants were recorded as event data, whereas implants that were removed because treatment ended and those that were not removed during the study period were recorded as censored data. A nonparametric life table method was used to visualize the hazard function, and Kaplan-Meier survival curves were generated to identify the variables associated with implant failure. Prognostic variables associated with implant failure were identified with the Cox proportional hazard model. RESULTS: Of the 260 implants, 22 failed. The hazard function for implant failure showed that the risk is highest immediately after placement. The survival function showed that the median survival time of orthodontic mini-implants is sufficient for relatively long orthodontic treatments. The Cox proportional hazard model identified that increasing age is a decisive factor for implant survival. CONCLUSIONS: The decreasing pattern of the hazard function suggested gradual osseointegration of orthodontic mini-implants. When implants are placed in a young patient, special caution is needed to lessen the increased probability of failure, especially immediately after placement.

Application of radially grown ZnO nanowires on poly-l-lactide microfibers complexed with a tumor antigen for cancer immunotherapy.

Zinc oxide (ZnO)-based nanocomposites have shown promising potential for various biomedical applications, including vaccine development, owing to their multifunctionality and biocompatibility. Here, we synthesized radially grown ZnO nanowires (NWs) on poly-l-lactic acid (PLLA) microfibers with unique 3-dimensional structure and applied them as therapeutic cancer vaccines. This inorganic-organic hybrid nanocomposite has mild cellular toxicity but efficiently delivers a tumor antigen into dendritic cells, cellular bridges between innate and adaptive immunity, to stimulate them to express inflammatory cytokines and activation surface markers. We also demonstrated that the hybrid nanocomposites successfully induce tumor antigen-specific cellular immunity and significantly inhibit tumor growth in vivo. ZnO NWs on PLLA fibers systemically reduced immune suppressive TReg cells and enhanced the infiltration of T cells into tumor tissues, compared to mice immunized with PLLA fibers coated with the antigen. Our current findings open a new avenue in extending the biomedical application of inorganic metal oxide-inert organic hybrid nanocomposites as a novel vaccine platform.

Enhancement of cellular binding efficiency and cytotoxicity using polyethylene glycol base triblock copolymeric nanoparticles for targeted drug delivery.

Folate (FA) conjugated tri-block copolymers were prepared by bioconjugation of poly epsilon-caprolactonediol and various molecular weights of diamine polyethylene glycol. The synthetic tri-block copolymers were characterized by 1H-NMR. Three types of nanoparticles were prepared by nanoprecipitation. Their size and morphology were verified by laser scattering and transmission electron microscopy, respectively. The colloidal stability of the nanoparticles was evaluated by turbidity test. The anticancer drug doxorubicin (DOX) was encapsulated in the nanoparticles during preparation. Drug loading amounts and release behavior from prepared nanoparticles were investigated. Fluorescent-activated cell sorting analysis and epi-fluorescencic microscopic imaging of prepared nanoparticles exhibited good cellular uptake against target cells. FA receptor expressed OVCAR3 cells that showed higher mean fluorescence intensity than FA receptor defect A549 cells at specific polyethylene glycol chain lengths. The cell cytotoxicity of prepared nanoparticles was evaluated for receptor mediated drug delivery.

Evaluation of waste mushroom logs as a potential biomass resource for the production of bioethanol.

In order to investigate the possibility of using waste mushroom logs as a biomass resource for alternative energy production, the chemical and physical characteristics of normal wood and waste mushroom logs were examined. Size reduction of normal wood (145 kW h/tone) required significantly higher energy consumption than waste mushroom logs (70 kW h/tone). The crystallinity value of waste mushroom logs was dramatically lower (33%) than normal wood (49%) after cultivation by Lentinus edodes as spawn. Lignin, an enzymatic hydrolysis inhibitor in sugar production, decreased from 21.07% to 18.78% after inoculation of L. edodes. Total sugar yields obtained by enzyme and acid hydrolysis were higher in waste mushroom logs than in normal wood. After 24h fermentation, 12 g/L ethanol was produced on waste mushroom logs, while normal wood produced 8 g/L ethanol. These results indicate that waste mushroom logs are economically suitable lignocellulosic material for the production of fermentable sugars related to bioethanol production.

Quantitative analysis of adhesion of cariogenic streptococci to orthodontic raw materials.

INTRODUCTION: Knowledge of adhesion patterns of cariogenic streptococci to orthodontic materials can provide valuable information on the cause of enamel demineralization during orthodontic treatment. The purpose of this study was to investigate the adhesion of 2 cariogenic streptococci strains to 7 orthodontic raw materials (3 light-cured orthodontic adhesives, 3 bracket raw materials, and hydroxyapatite) with respect to bacterial species, incubation time, and saliva coating. METHODS: Each material was incubated with unstimulated whole saliva or phosphate-buffered saline solution for 2 hours. Binding assays were then performed by incubating tritium-labeled cariogenic streptococci with each raw material for 3 or 6 hours. RESULTS: The degree of adhesion varied by material type. Generally, adhesion of cariogenic streptococci was significantly higher for bonding adhesives than for bracket materials, and adhesion to resin-modified glass ionomer was the highest. A longer incubation time generally increased bacterial adhesion, whereas saliva coating did not significantly influence bacterial adhesion. CONCLUSIONS: Bonding adhesives around brackets should be removed carefully during the bonding procedure to avoid enamel decalcification.

Enzyme adsorption properties on dilute acid pretreated biomass by low vacuum-scanning electron microscopy and structural analysis of lignin.

In this study, enzyme adsorption properties were investigated as a function of the structural change of lignin in dilute acid pretreated biomass using oxalic and sulfuric acid catalysts under the same reaction conditions. Although the contents of glucan and lignin in the dilute acid pretreated biomass were similar regardless of the catalysts used, the enzymatic hydrolysis efficiency and degree of enzyme adsorption differed considerably. The highest efficiencies were 87.79% and 96.49% for the oxalic acid and sulfuric acid catalysts, respectively. The reasons for this observation were investigated by low vacuum-scanning electron microscopy and the structural analysis of lignin. In the oxalic acid pretreated biomass, the enzyme was irreversibly adsorbed onto the lignin. The oxalic acid pretreated biomass possessed a higher content of G-type lignin than did the sulfuric acid pretreated biomass. This type of lignin has a high affinity for the enzyme, inducing irreversible enzyme adsorption onto the biomass.

Biological pretreatment of softwood Pinus densiflora by three white rot fungi.

The effects of biological pretreatment on the Japanese red pine Pinus densiflora, was evaluated after exposure to three white rot fungi Ceriporia lacerata, Stereum hirsutum, and Polyporus brumalis. Change in chemical composition, structural modification, and their susceptibility to enzymatic saccharification in the degraded wood were analyzed. Of the three white rot fungi tested, S. hirsutum selectively degraded the lignin of this sortwood rather than the holocellulose component. After eight weeks of pretreatment with S. hirsutum, total weight loss was 10.7%, while lignin loss was the highest at 14.52% among the tested samples. However, holocellulose loss was lower at 7.81% compared to those of C. lacerata and P. brumalis. Extracelluar enzymes from S. hirsutum showed higher activity of ligninase and lower activity of cellulase than those from other white rot fungi. Thus, total weight loss and changes in chemical composition of the Japanese red pine was well correlated with the enzyme activities related with lignin- and cellulose degradation in these fungi. Based on the data obtained from analysis of physical characterization of degraded wood by X-ray Diffractometry (XRD) and pore size distribution, S. hirsutum was considered as an effective potential fungus for biological pretreatment. In particular, the increase of available pore size of over 120 nm in pretreated wood powder with S. hirsutum made enzymes accessible for further enzymatic saccharification. When Japanese red pine chips treated with S. hirsutum were enzymatically saccharified using commercial enzymes (Cellulclast 1.5 L and Novozyme 188), sugar yield was greatly increased (21.01%) compared to non-pretreated control samples, indicating that white rot fungus S. hirsutum provides an effective process in increasing sugar yield from woody biomass.