Hydrolysis of propyrisulfuron in water: Kinetics, influence of 34 environmental factors, transformation products identification, mechanisms and toxicities.

Propyrisulfuron is a novel sulfonylurea herbicide used for controlling annual grass and broad-leaved weeds in fields, but its fates and behaviors in environment are still unknown, which are of utmost importance for environmental protection. To reduce its potential environmental risks in agricultural production, the hydrolysis kinetics, influence of 34 environmental factors including 12 microplastics (MPs), disposable face masks (DFMs) and its different parts, 6 fertilizers, 5 ions, 3 surfactants, a co-existed herbicide of florpyrauxifen-benzy, humic acid and biochar, and the effect of MPs and DFMs on its hydrolysis mechanisms were systematically investigated. The main hydrolysis products (HPs), possible mechanisms, toxicities and potential risks to aquatic organisms were studied. Propyrisulfuron hydrolysis was an acid catalytic pyrolysis, endothermic and spontaneous process driven by the reduction of activation enthalpy, and followed the first-order kinetics. All environmental factors can accelerate propyrisulfuron hydrolysis to varying degrees except humic acid, and different hydrolysis mechanisms occurred in the presence of MPs and DFMs. In addition, 10 possible HPs and 7 possible mechanisms were identified and proposed. ECOSAR prediction and ecotoxicity testing showed that acute toxicity of propyrisulfuron and its HPs for aquatic organisms were low, but may have high chronic toxicity and pose a potential threat to aquatic ecosystems. The investigations are significantly important for elucidating the environmental fates and behaviors of propyrisulfuron, assessing the risks in environmental protection, and further providing guidance for scientific application in agro-ecosystem.

Preparation of a novel regenerated silk fibroin-based hydrogel for extrusion bioprinting.

Three-dimensional (3D) bioprinting technology, allowing rapid prototyping and personalized customization, has received much attention in recent years, while regenerated silk fibroin (RSF) has also been widely investigated for its excellent biocompatibility, processibility, and comprehensive mechanical properties. However, due to the difficulty in curing RSF aqueous solution and the tendency of conformational transition of RSF chains under shearing, it is rather complicated to fabricate RSF-based materials with high mechanical strength through extrusion bioprinting. To solve this problem, a printable hydrogel with thixotropy was prepared from regenerated silk fibroin with high-molecular-weight (HMWRSF) combined with a small amount of hydroxypropyl methylcellulose (HPMC) in urea containing aqueous solution. It was found that the introduction of urea could not only vary the solid content of the hydrogel to benefit the mechanical properties of the 3D-bioprinted pre-cured hydrogels or 3D-bioprinted sponges, but also expand the "printable window" of this system. Indeed, the printability and rheological properties could be modulated by varying the solid content, the heating time, the urea/HMWRSF weight ratio, etc. Moreover, the microstructure of nanospheres stacked in these lyophilized 3D-bioprinted sponges was interesting to observe, which indicated the existence of microhydrogels and both "the reversible network" and "the irreversible network" in this HMWRSF-based pre-cured hydrogel. Like other HMWRSF materials fabricated in other ways, these 3D-bioprinted HMWRSF-based sponges exhibited good cytocompatibility for dental pulp mesenchymal stem cells. This work may inspire the design of functional HMWRSF-based materials by regulating the relationship between structure and properties.

Evaluation of enhancing effect of soybean oil on polymalic acid production by Aureobasidium pullulans HA-4D.

Polymalic acid (PMA) is a water-soluble polyester produced by Aureobasidium pullulans. In this study, the physiological response of A. pullulans after the addition of vegetable oils was investigated. Soybean oil (SBO) is pivotal for shortening fermentation time and achieving high PMA titer. With the addition of 1% (w/v) SBO, the titer and productivity of PMA was, respectively, increased by 34.2% and 80%. SBO acted as a chemical stimulatory agent rather than a carbon source, the enhancement on PMA production was attributed to the component of fatty acid. SBO induced the dimorphism (yeast-like cells and mycelia) of A. pullulans, in vitro enzyme activities indicated that the TCA oxidative branch for malic acid synthesis might be strengthened, which could generate more ATP for PMA synthesis, and the assay of intracellular energy supply validated this deduction. This study provided a new sight for recognizing the regulatory behavior of SBO in A. pullulans.

Economic co-production of poly(malic acid) and pullulan from Jerusalem artichoke tuber by Aureobasidium pullulans HA-4D.

BACKGROUND: poly(L-malic acid) (PMA) is a water-soluble polyester with many attractive properties in medicine and food industries, but the high cost of PMA fermentation has restricted its further application for large-scale production. To overcome this problem, PMA production from Jerusalem artichoke tubers was successfully performed. Additionally, a valuable exopolysaccharide, pullulan, was co-produced with PMA by Aureobasidum pullulans HA-4D. RESULTS: The Jerusalem artichoke medium for PMA and pullulan co-production contained only 100 g/L hydrolysate sugar, 30 g/L CaCO3 and 1 g/L NaNO3. Compared with the glucose medium, the Jerusalem artichoke medium resulted in a higher PMA concentration (114.4 g/L) and a lower pullulan concentration (14.3 g/L) in a 5 L bioreactor. Meanwhile, the activity of pyruvate carboxylase and malate dehydrogenas was significantly increased, while the activity of α-phosphoglucose mutase, UDP-glucose pyrophosphorylase and glucosyltransferase was not affected. To assay the economic-feasibility, large-scale production in a 1 t fermentor was performed, yielding 117.5 g/L PMA and 15.2 g/L pullulan. CONCLUSIONS: In this study, an economical co-production system for PMA and pullulan from Jerusalem artichoke was developed. The medium for PMA and pullulan co-production was significantly simplified when Jerusalem artichoke tubers were used. With the simplified medium, PMA production was obviously stimulated, which would be associated with the improved activity of pyruvate carboxylase and malate dehydrogenas.

Axial PEGylation of Tin Octabutoxy Naphthalocyanine Extends Blood Circulation for Photoacoustic Vascular Imaging.

Attachment of polyethylene glycol (PEG) can prolong blood circulation of biological molecules, a useful trait for a vascular imaging agent. Here, we present a route for modifying octabutoxy naphthalocyanine (ONc) with PEG, via axial conjugation following ONc chelation with Sn(IV) chloride (Sn-ONc). Tin chelation caused ONc absorbance to shift from 860 to 930 nm. Hydroxy terminated PEG was treated with sodium and then was axially attached to the tin, generating PEG-Sn-ONc. Unlike ONc or Sn-ONc, PEG-Sn-ONc was soluble in methanol. ONc and PEG-Sn-ONc were dissolved in polysorbate solutions and administered to mice intravenously. PEG-Sn-ONc demonstrated substantially longer blood circulation time than ONc, with a 4 times longer half-life and a nearly 10 times greater area under the curve. PEG-Sn-ONc gave rise to photoacoustic contrast and could be used for noninvasive brain vessel imaging even 24 h following injection. This work demonstrates that nonmetallic naphthalocyanines can be chelated with tin, and be axially modified with PEG for enhanced circulation times for long-term vascular imaging with photoacoustic tomography.

Enhanced poly(L-malic acid) production from pretreated cane molasses by Aureobasidium pullulans in fed-batch fermentation.

Poly(L-malic acid) (PMA) is a natural polyester with many attractive properties for biomedical application. However, the cost of PMA production is high when glucose is used as a carbon source. To solve this problem, cane molasses as a low-cost feedstock was applied for the production of PMA. Six pretreatment methods were applied to cane molasses before fermentation. Pretreatment with combined tricalcium phosphate, potassium ferrocyanide, and sulfuric acid (TPFSA) removed significant amounts of metal ions from cane molasses. The PMA concentration increased from 5.4 g/L (untreated molasses) to 36.9 g/L (TPFSA-pretreated molasses) after fermentation in shake flasks. A fed-batch fermentation strategy was then developed. In this method, TPFSA-pretreated cane molasses solution was continuously fed into the fermentor to maintain the total sugar concentration at 20 g/L. This technique generated approximately 95.4 g/L PMA with a productivity of 0.57 g/L/hr. The present study indicated that fed-batch fermentation using pretreated cane molasses is a feasible technique for producing high amounts of PMA.

Synthesis of fluorescent and low cytotoxicity phenol formaldehyde resin (PFR)@Ag composites for cell imaging and antibacterial activity.

Ag nanoparticles (NPs) were loaded onto the surface of phenol formaldehyde resin (PFR) NPs without any reducing agent. The as-synthesized PFR@Ag composites have low cytotoxicity, which makes them promising antibacterial agents. Furthermore, the good fluorescence of PFR could be used for cell imaging.

Acupuncture for schizophrenia.

BACKGROUND: Acupuncture, with many categories such as traditional acupuncture, electroacupuncture, laser acupuncture, and acupoint injection, has been shown to be relatively safe with few adverse effects. It is accessible and inexpensive, at least in China, and is likely to be widely used there for psychotic symptoms. OBJECTIVES: To review the effects of acupuncture, alone or in combination treatments compared with placebo (or no treatment) or any other treatments for people with schizophrenia or related psychoses. SEARCH METHODS: We searched Cochrane Schizophrenia Group's Trials Register (February 2012), which is based on regular searches of CINAHL, BIOSIS, AMED, EMBASE, PubMed, MEDLINE, PsycINFO and clinical trials registries. We also inspected references of identified studies and contacted relevant authors for additional information. SELECTION CRITERIA: We included all relevant randomised controlled trials involving people with schizophrenia-like illnesses, comparing acupuncture added to standard dose antipsychotics with standard dose antipsychotics alone, acupuncture added to low dose antipsychotics with standard dose antipsychotics, acupuncture with antipsychotics, acupuncture added to Traditional Chinese Medicine (TCM) drug with TCM drug, acupuncture with TCM drug, electric acupuncture convulsive therapy with electroconvulsive therapy. DATA COLLECTION AND ANALYSIS: We reliably extracted data from all included studies, discussed any disagreement, documented decisions and contacted authors of studies when necessary. We analysed binary outcomes using a standard estimation of risk ratio (RR) and its 95% confidence interval (CI). For continuous data, we calculated mean differences with 95% CI. For homogeneous data we used fixed-effect model. We assessed risk of bias for included studies and created 'Summary of findings' tables using GRADE. MAIN RESULTS: After an update search in 2012 the review now includes 30 studies testing different forms of acupuncture across six different comparisons. All studies were at moderate risk of bias.When acupuncture plus standard antipsychotic treatment was compared with standard antipsychotic treatment alone, people were at less risk of being 'not improved' (n = 244, 3 RCTs, medium-term RR 0.40 CI 0.28 to 0.57, very low quality evidence). Mental state findings were mostly consistent with this finding as was time in hospital (n = 120, 1 RCT, days MD -16.00 CI -19.54 to -12.46, moderate quality evidence). If anything, adverse effects were less for the acupuncture group (e.g. central nervous system, insomnia, short-term, n = 202, 3 RCTs, RR 0.30 CI 0.11 to 0.83, low quality evidence).When acupuncture was added to low dose antipsychotics and this was compared with standard dose antipsychotic drugs, relapse was less in the experimental group (n = 170, 1 RCT, long-term RR 0.57 CI 0.37 to 0.89, very low quality evidence) but there was no difference for the outcome of 'not improved'. Again, mental state findings were mostly consistent with the latter. Incidences of extrapyramidal symptoms - akathisia, were less for those in the acupuncture added to low dose antipsychotics group (n = 180, 1 RCT, short-term RR 0.03 CI 0.00 to 0.49, low quality evidence) - as dry mouth, blurred vision and tachycardia.When acupuncture was compared with antipsychotic drugs of known efficacy in standard doses, there were equivocal data for outcomes such as 'not improved' using different global state criteria. Traditional acupuncture added to TCM drug had benefit over use of TCM drug alone (n = 360, 2 RCTs, RR no clinically important change 0.11 CI 0.02 to 0.59, low quality evidence), but when traditional acupuncture was compared with TCM drug directly there was no significant difference in the short-term. However, we found that participants given electroacupuncture were significantly less likely to experience a worsening in global state (n = 88, 1 RCT, short-term RR 0.52 CI 0.34 to 0.80, low quality evidence).In the one study that compared electric acupuncture convulsive therapy with electroconvulsive therapy there were significantly different rates of spinal fracture between the groups (n = 68, 1 RCT, short-term RR 0.33 CI 0.14 to 0.81, low quality evidence). Attrition in all studies was minimal. No studies reported death, engagement with services, satisfaction with treatment, quality of life, or economic outcomes. AUTHORS' CONCLUSIONS: Limited evidence suggests that acupuncture may have some antipsychotic effects as measured on global and mental state with few adverse effects. Better designed large studies are needed to fully and fairly test the effects of acupuncture for people with schizophrenia.

The regulatory effect of citric acid on the co-production of poly(ε-lysine) and poly(L-diaminopropionic acid) in Streptomyces albulus PD-1.

Streptomyces albulus PD-1 can co-produce antimicrobial homo-polymers poly(ε-lysine) (ε-PL) and poly(L-diaminopropionic acid) (PDAP). In this study, a novel feeding strategy of citric acid coupled with glucose-(NH4)2SO4 feeding was employed to S. albulus PD-1. When the pH of the culture broth dropped to 4.0, the feeding solution was added continuously to maintain the concentrations of glucose and citric acid at 10 and 4 g L(-1), respectively. As a result, the final concentration of ε-PL increased from 21.7 to 29.7 g L(-1) and the final concentration of PDAP decreased from 4.8 to 3.2 g L(-1). Assays on intracellular nucleotide levels and key enzyme activities were performed to elucidate the underlying regulation mechanism. The addition of citric acid increased NADH/NAD(+) ratio and decreased intracellular ATP level; meanwhile, the activities of pyruvate kinase, citrate synthase and isocitrate dehydrogenase decreased while aspartate aminotransferase activity increased. Therefore, we deduced that citric acid feeding resulted in metabolic flux redistribution at the node of phosphoenolpyruvate; the metabolic pathway from phosphoenolpyruvate directed into tricarboxylic acid cycle was weakened and thus PDAP production was inhibited. On the other hand, the metabolic pathway from phosphoenolpyruvate directed into oxaloacetate and L-aspartate was enhanced, thereby improving ε-PL production. This fermentation strategy may be potentially useful in ε-PL production because it can effectively inhibit the formation of by-products, such as PDAP.

The long-term release and particle fracture behaviors of nanoplastics retained in porous media: Effects of surfactants, natural organic matters, antibiotics, and bacteria.

The transport of nanoplastics (NPs) in porous media has received a lot of attention, but the studies on the long-term release of NPs retained in porous media and the particle fracture during this process are seriously lacking. For filling this deficiency, we examined the individual or synergistic effects of surfactants, natural organic matters (NOMs), antibiotics, and bacteria on the desorption, long-term release, and particle fracture behaviors of polystyrene NPs (PS-NPs) retained in porous media. It was found that the change in hydrophilicity of PS-NPs dominated the long-term release of PS-NPs retained in porous media when surfactants were present. In the single system of surfactants and the dual system of surfactants and NOMs, the release of PS-NPs were improved owing to the increasing hydrophilicity of PS-NPs, although cationic surfactants also reduced the electrostatic repulsion between PS-NPs and porous media. Increasing antibiotic concentration reduced the electrostatic repulsion between PS-NPs and porous media to inhibit the release of PS-NPs. When bacteria were present whether containing antibiotics or not, the effects on roughness of PS-NPs dominated the release of PS-NPs. The effects of surfactants and NOMs on the PS-NP desorption were similar with the long-term release, with changes in hydrophilicity dominating the process. Whereas the effects of antibiotics and bacteria on the PS-NP desorption were different with the long-term release. Surfactants and NOMs in the presence of surfactants inhibited the fracture of PS-NPs by increasing the hydrophilicity of PS-NPs brought about the coating of water molecules on PS-NPs for protection. Antibiotics had no significant effects on the fracture of PS-NPs due to unaltered vertical forces on PS-NPs and no protective effect. Bacteria in the presence or absence of antibiotics inhibited the fracture of PS-NPs by coating PS-NPs retained in porous media to protect PS-NPs from fracture.

Niobium-based single-atom catalyst promoted fractionation of lignocellulose in choline chloride-lactic acid deep eutectic solvent.

Pretreatment is the key step to convert lignocelluloses to sustainable biofuels, biochemicals or biomaterials. In this study, a green pretreatment method based on choline chloride-lactic acid deep eutectic solvent (ChCl-LA) and niobium-based single-atom catalyst (Nb/CN) was developed for the fractionation of corn straw and further enzymatic hydrolysis of cellulose. With this strategy, significant lignin removal of 96.5 % could be achieved when corn straw was pretreated by ChCl-LA (1:2) DES over Nb/CN under 120 °C for 6 h. Enzymatic hydrolysis of the cellulose-enriched fraction (CEF) presented high glucose yield of 92.7 % and xylose yield of 67.5 %. In-depth investigations verified that the high yields of fractions and monosaccharides was attributed to the preliminary fractionation by DES and the deep fractionation by Nb/CN. Significantly, compared to other reported soluble catalysts, the synthesized single-atom catalyst displayed excellent reusability by simple filtration and enzymatic hydrolysis. The recyclability experiments showed that the combination of ChCl-LA DES and Nb/CN could be repeated at least three times for corn straw fractionation, moreover, the combination displayed remarkable feedstock adaptability.

Poly(L-diaminopropionic acid), a novel non-proteinic amino acid oligomer co-produced with poly(ε-L-lysine) by Streptomyces albulus PD-1.

Poly(ε-L-lysine) (ε-PL) producer strain Streptomyces albulus PD-1 secreted a novel polymeric substance into its culture broth along with ε-PL. The polymeric substance was purified to homogeneity and identified. Matrix-assisted laser desorption ionization-time of flight mass spectrometry and nuclear magnetic resonance spectroscopy as well as other analytical techniques revealed that the substance was poly(L-diaminopropionic acid) (PDAP). PDAP is an L-α,ß-diaminopropionic acid oligomer linking between amino and carboxylic acid functional groups. The molecular weight of PDAP ranged from 500 to 1500 Da, and no co-polymers composed of L-diaminopropionic acid and L-lysine were present in the culture broth. Compared with ε-PL, PDAP exhibited stronger inhibitory activities against yeasts but weaker activities against bacteria. ε-PL and PDAP co-production was also investigated. Both ε-PL and PDAP were synthesized during the stationary phase of growth, and the final ε-PL and PDAP concentration reached 21.7 and 4.8 g L(-1), respectively, in fed-batch fermentation. Citric acid feeding resulted in a maximum ε-PL concentration of 26.1 g L(-1) and a decrease in the final concentration of PDAP to 3.8 g L(-1). No studies on ε-PL and PDAP co-production in Streptomyces albulus have been reported previously, and inhibition of by-products such as PDAP is potentially useful in ε-PL production.

Influences of input concentration, media particle size, metal cation valence, and ionic concentration on the transport, long-term release, and particle breakage of polyvinyl chloride nanoplastics in saturated porous media.

The environmental impact of nanoplastics has gradually attracted widespread attention; however, nanoplastics of polyvinyl chloride, one of the most commonly used plastics, have not yet been studied. In this study, we investigated the transport, long-term release behavior, and particle fracture of polyvinyl chloride nanoplastics (PVC NPs) in saturated quartz sand with different metal cations, ionic concentrations, input concentrations, and sand grain sizes by determining breakthrough, long-term release, and particle size distribution curves. The breakthrough curves and retention profiles were simulated by a mathematical model. The transport of PVC NPs increased with increased input concentration and sand grain size, which could be predicted by the Derjaguin-Landau-Verwey-Overbeek (DLVO) and colloid filtration theories. Increased ionic concentration and metal cation valence could restrain the transport of PVC NPs in saturated quartz sand owing to the decreased energy barrier between PVC NPs and sand grains. The total released amount of PVC NPs in the long-term release tests with different experimental conditions ranged from 3.91 to 21.95%. Increased sand grain size and decreased metal cation valence and ionic concentration resulted in an increased released amount of retained PVC NPs in saturated quartz sand, indicating increased release ability and mobility. The particle fracture results indicated that the PVC NPs were not broken down during long-term release under the experimental conditions of this research. This opens up a completely new and meaningful study of whether nanoplastics are broken down into smaller nanoplastics during their long-term release under various conditions.

Enhanced cellulosic d-lactic acid production from sugarcane bagasse by pre-fermentation of water-soluble carbohydrates before acid pretreatment.

After several rounds of milling process for sugars extraction from sugarcane, certain amounts of water-soluble carbohydrates (WSC) still remain in sugarcane bagasse. It is a bottleneck to utilize WSC in sugarcane bagasse biorefinery, since these sugars are easily degraded into inhibitors during pretreatment. Herein, a simple pre-fermentation step before pretreatment was conducted, and 98 % of WSC in bagasse was fermented into d-lactic acid. The obtained d-lactic acid was stably preserved in bagasse and 5-hydroxymethylfurfural (HMF) generation was sharply reduced from 46.0 mg/g to 6.2 mg/g of dry bagasse, after dilute acid pretreatment. Consequently, a higher d-lactic acid titer (57.0 g/L vs 33.2 g/L) was achieved from the whole slurry of the undetoxified and pretreated sugarcane bagasse by one-pot simultaneous saccharification and co-fermentation (SSCF), with the overall yield of 0.58 g/g dry bagasse. This study gave an efficient strategy for enhancing lactic acid production using the lignocellulosic waste from sugar industry.

A novel mutation of gap junction protein ß 1 gene in X-linked Charcot-Marie-Tooth disease.

INTRODUCTION: In this study we report a novel mutation in the gap junction protein beta 1 (GJB1) gene of a Chinese X-linked Charcot-Marie-Tooth disease (CMTX1) family, which has specific electrophysiological characteristics. METHODS: Twenty members in the family were studied by clinical neurological examination and GJB1 gene mutation analysis, and 3 patients were studied electrophysiologically. The proband and his mother also underwent sural nerve biopsy. RESULTS: All patients have the CMT phenotype, except for 2 asymptomatic carriers. Electrophysiological examinations showed non-uniform slowing of motor conduction velocities and partial motor conduction blocks and temporal dispersion. Sural nerve biopsy confirmed a predominantly demyelinating neuropathy, and an Asn2Lys mutation in the amino-terminal domain was found in 9 members of this family, but not in 25 normal controls in the family. CONCLUSIONS: This family represents a novel mutation in the GJB1 form of CMTX1. The mutation in the amino-terminus has an impact on the electrophysiological characteristics of the disease.

Direct conversion of cheese whey to polymalic acid by mixed culture of Aureobasidium pullulans and permeabilized Kluyveromyces marxianus.

Cheese whey is an abundant and low-cost feedstock with lactose as its main component, but the inability to metabolize lactose prevents Aureobasidium pullulans from using cheese whey directly. In this study, Kluyveromyces marxianus was permeabilized to obtain nonviable but biocatalytic cells for lactose hydrolysis, and the mixed culture of A. pullulans and permeabilized K. marxianus was conducted for polymalic acid (PMA) production from cheese whey. In the mixed culture, PMA titer varied directly to ß-galactosidase activity of K. marxianus, but inversely to cell viability of K. marxianus, and ethanol permeabilized K. marxianus was the most compatible with A. pullulans for PMA production. 37.8 g/L PMA was produced in batch fermentation, and PMA titer was increased to 97.3 g/L in fed-batch fermentation, with a productivity of 0.51 g/(L·h) and a yield of 0.56 g/g. This study paved an economical and environmentally friendly way for PMA production from cheese whey.

One-step utilization of non-detoxified pretreated lignocellulose for enhanced cellulolytic enzyme production using recombinant Trichoderma reesei RUT C30 carrying alcohol dehydrogenase and nicotinate phosphoribosyltransferase.

Cell growth of Trichoderma reesei is greatly inhibited by furan derivatives (furfural and HMF) generated during pretreatment of lignocellulose, and the cellulase production is hence suppressed. In this study, a novel recombinant strain of T. reesei with high tolerance to furans was constructed by homologously co-expressing nicotinate phosphoribosyltransferase and alcohol dehydrogenase. We observed that furfural had a stronger inhibitory effect than HMF and cellulase production was decreased by 35% in T. reesei with the stress of 2.5 mM furfural. The activities of nicotinate phosphoribosyltransferase and alcohol dehydrogenase increased 8.6-fold and 2.9-fold in the recombinant strain, respectively. Furfural was effectively converted into furfuryl alcohol which was then depleted, thus the production of cellulase could be recovered when the recombinant strain was grown in 5% (w/v) two-step stem explosion pretreated rice straw without detoxification. This work presents an important strategy for efficient enzyme production in T. reesei from non-detoxified pretreated lignocellulose feedstocks.

A silk-based high impact composite for the core decompression of the femoral head.

Core decompression of the femoral head is a recommended head-conserving strategy for early-stage osteonecrosis of the femoral head. However, no ideal filling material has been found so far. In this study, we fabricated a "solid core-porous coating" composite scaffold, which is a silk fibroin/hydroxypropyl methylcellulose (SF/HPMC) scaffold, by a "two-step" process. The solid core scaffold possesses a sufficient compression modulus (860 MPa) for support, while the porous coating scaffold with controllable pore size and porosity provides a suitable microenvironment for the osteoblast cell to adhere and proliferate. Moreover, the porous coating scaffold was mineralized by adding different contents of hydroxyapatite crystal to further enhance its osteoinductivity, according to the simulated body fluid (SBF) biomineralization assay. To demonstrate the biocompatibility and osteoinductivity of such composite scaffolds, a series of in vitro experiments were performed, indicating the MC3T3-E1 pre-osteoblast cells grew and differentiated well on the mineralized porous coating scaffolds. The mechanical testing results also proved that the mechanical property of the solid core scaffold varied (230-1600 MPa) with different solid contents of SF/HPMC, as expected. Furthermore, the rabbit femoral head core decompression model was adopted and confirmed the excellent mechanical performance of the solid core scaffolds, as well as the satisfied osteoinductivity of the porous coating scaffold, by inserting the composite scaffolds into the bone tunnel in vivo. All of the preliminary results implied that the novel biodegradable composite scaffold has an outstanding prospective for the clinical use of core decompression of the femoral head.

Highly-Soluble Cyanine J-aggregates Entrapped by Liposomes for In Vivo Optical Imaging around 930 nm.

Near infrared (NIR) dyes are useful for in vivo optical imaging. Liposomes have been used extensively for delivery of diverse cargos, including hydrophilic cargos which are passively loaded in the aqueous core. However, most currently available NIR dyes are only slightly soluble in water, making passive entrapment in liposomes challenging for achieving high optical contrast. Methods: We modified a commercially-available NIR dye (IR-820) via one-step Suzuki coupling with dicarboxyphenylboronic acid, generating a disulfonated heptamethine; dicarboxyphenyl cyanine (DCP-Cy). DCP-Cy was loaded in liposomes and used for optical imaging. Results: Owing to increased charge in mildly basic aqueous solution, DCP-Cy had substantially higher water solubility than indocyanine green (by an order of magnitude), resulting in higher NIR absorption. Unexpectedly, DCP-Cy tended to form J-aggregates with pronounced spectral red-shifting to 934 nm (from 789 nm in monomeric form). J-aggregate formation was dependent on salt and DCP-Cy concentration. Dissolved at 20 mg/mL, DCP-Cy J-aggregates could be entrapped in liposomes. Full width at half maximum absorption of the liposome-entrapped dye was just 25 nm. The entrapped DCP-Cy was readily detectable by fluorescence and photoacoustic NIR imaging. Upon intravenous administration to mice, liposomal DCP-Cy circulated substantially longer than the free dye. Accumulation was largely in the spleen, which was visualized with fluorescence and photoacoustic imaging. Conclusions: DCP-Cy is simple to synthesize and exhibits high aqueous solubility and red-shifted absorption from J-aggregate formation. Liposomal dye entrapment is possible, which facilitates in vivo photoacoustic and fluorescence imaging around 930 nm.

Synergistic effects of metal salt and ionic liquid on the pretreatment of sugarcane bagasse for enhanced enzymatic hydrolysis.

High cost of ionic liquids (ILs) restricts the industrial application of IL-mediated lignocellulose pretreatment. In this study, a simple and economic technology for the pretreatment of natural lignocellulose was developed. The delignification capacity of aqueous choline ornithine ([Cho][Orn]) and hemicellulose-removal capacity of metal salt FeCl2 were combined. The changes of morphological structure and composition indicated a synergistic interaction of [Cho][Orn] and FeCl2 in the pretreatment process. The delignification and hemicellulose-removal capacity of aqueous [Cho][Orn]50% solution was significantly improved in the presence of FeCl2 by 28% and 53%, respectively. The combination use of FeCl2 and [Cho][Orn] made it possible to save the amount of IL used for pretreatment in half. Enhancement effect of metal salts on the IL-pretreatment efficiency was proved.