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The precise disconnection of one type of chemical bond in polymers realizes high-yield recovery of valuable chemicals. In this study, we demonstrate a sustainable and efficient strategy to selectively cleave the specific sp3C–sp3N bond of a thermoset melamine–formaldehyde foam, by which valuable melamine of 99.5% purity was obtained with a yield of 95.3%. [ABSTRACT FROM AUTHOR]

As a kind of super stable thermoset resin, phenolic epoxy vinyl ester resin (PEVER) is widely applied as a solvent and corrosion resistant material. However, its highly cross-linked three-dimensional network challenges its degradation and recycling. In this study, we report an efficient catalytic system of KOH/C2H5OH–H2O to degrade PEVER under a mild reaction condition of 160 °C. It is discovered that the efficiency of KOH for degrading PEVER resulted from the high affinity of K+ to PEVER. Besides the resin, K+ shows good affinity to other organic substances, such as ethyl acetate, toluene, and petroleum ether, and it surpassed largely Na+ (NaOH) in the affinity to organic substances. The NMR and FT-IR characterizations indicated the degradation of PEVER via the hydrolysis of ester bonds, by which high value-added copolymer of styrene and methacrylic acid (SMAA), potassium salt of SMAA (SMAA-K), and novolac glycidyl ether (NOGE) were obtained. SMAA-K can be used as an interface modifier owing to its surface activity. The modified filter paper prepared by SMAA has high hydrophobicity. NOGE can be recycled to prepare a new polyurethane material. This study provides a new strategy for the chemical degradation and recycling of thermoset PEVER waste. [ABSTRACT FROM AUTHOR]

5-Chloro-2-pentanone (5C2P) and its derivatives are widely utilized in the pharmaceutical and agrochemical industry. A new catalytic approach was proposed to convert 3-acetyl-1-propanol to 5C2P using bis(trichloromethyl)carbonate (triphosgene, BTC) as the efficient chlorine source. Various qualitative and quantitative nuclear magnetic resonance techniques (1H, 13C NMR), especially 1D selective gradient total correlation spectroscopy (Sel-TOCSY) and 2D heteronuclear single quantum correlation (1H-13C HSQC) were used in the process. The reaction conditions, such as temperature, time, mole ratio, solvent as well as initiator were optimized. Experiment results showed that the yield of 5C2P reached a maximum of 97.93% in 1,2-dichloroethane at 80 °C after 2 h under the initiation of N,N-dimethylacetamide, and the optimal molar ratio of 3-acetyl-1-propanol to BTC was 1:0.4. The reaction mechanism was proposed and confirmed accordingly. Interestingly, an intermediate product of 1-(dimethylamino)ethyl carbonochloridate was observed, and its chemical structure was characterized by both Sel-TOCSY and 1H-13C HSQC. This study enriched the catalytic reaction ways for the preparation of 5C2P. [ABSTRACT FROM AUTHOR]

A novel strategy was proposed for the complete degradation of anhydride-cured epoxy resin (ACEP) by an amphiphilic catalyst in water under mild conditions. As an amphiphilic molecule, dodecyl benzene sulfonic acid (DBSA) was enriched at the water–ACEP interface, accelerating the degradation of ACEP. Moreover, it could carry the degradation products away from ACEP, which facilitated the exposure of the ACEP surface to the catalyst and further the degradation of ACEP. [ABSTRACT FROM AUTHOR]

The primary functions of the bladder are storing urine under low and stable pressure and micturition. Various forms of trauma, tumors, and iatrogenic injuries can cause the loss of or reduce bladder function or capacity. If such damage is not treated in time, it will eventually lead to kidney damage and can even be life-threatening in severe cases. The emergence of tissue engineering technology has led to the development of more possibilities for bladder repair and reconstruction, in which the selection of scaffolds is crucial. In recent years, a growing number of tissue-engineered bladder scaffolds have been constructed. Therefore, this paper will discuss the development of tissue-engineered bladder scaffolds and will further analyze the limitations of and challenges encountered in bladder reconstruction. [ABSTRACT FROM AUTHOR]

Renal ischemia-reperfusion (I/R) injury is one of the major causes of acute kidney injury. However, there is still no effective treatment for this disease. Basic fibroblast growth factor (bFGF) has been reported to be beneficial for recovery from ischemic diseases. It is vital to increase the local concentration and reduce the diffusion of bFGF in vivo for renal I/R injury therapy. A targeted growth factor delivery system that responds to specific biological signals in the regenerative environment to guide release has been highlighted in tissue repair. In the present study, a specific peptide was fused with bFGF and called bFGF-kidney injury targeting (KIT-bFGF), and this compound specifically targeted kidney injury molecule-1 both in hypoxic renal HK-2 cells in vitro and ischemic kidneys in vivo after intravenous injection. When administered to rat models of renal I/R injury, KIT-bFGF attenuated renal tubule damage and fibrosis, and promoted functional recovery compared to the effects of native bFGF and the control. We also investigated the mechanism by which KIT-bFGF activated the ERK1/2 and Akt signaling pathways to significantly reduce apoptosis and protect against ischemic injury in the kidney. These results demonstrated that targeted delivery of KIT-bFGF could be an effective strategy for the treatment of renal I/R injury. [ABSTRACT FROM AUTHOR]

Objectives. Urethral tissue reconstruction for hypospadias is challenging for urologists. In this study, bovine acellular dermal matrix (ADM) patch loading with collagen-binding vascular endothelial growth factor (CBD-VEGF) was used to repair the urethral injury in beagles. Methods. The safety and effectiveness of the scaffold implantation were carefully evaluated by comparing among the urethral injury control group, ADM implantation group, and ADM modified with CBD-VEGF implantation group during 6 months. Urodynamic examination, urethral angiography, and pathological examination were performed to evaluate the recovery of urethral tissue. Results. Stricture, urethral diverticulum, and increased urethral closure pressure were observed in the control group. Fistula was observed in one animal in the ADM group. By contrast, no related complications or other adverse situations were observed in animals treated with ADM patch modified with CBD-VEGF. The average urethra diameter was significantly smaller in the control animals than in scaffold implantation groups. Pathological examination revealed more distribution of proliferative blood vessels in the animals treated with ADM modified with CBD-VEGF. Conclusions. Overall, ADM patches modified with CBD-VEGF demonstrated an optimized tissue repair performance in a way to increase tissue angiogenesis and maintain urethral function without inducing severe inflammation and scar formation. [ABSTRACT FROM AUTHOR]

The wide application of melamine–formaldehyde resins (MFRs) in the food industry aggravates plastic pollution problems. Recycling of the waste MFRs remains a big challenge due to its compact structure. Herein, a high MFR degradation ratio of ca. 84 wt% was achieved under mild conditions (180 °C) in a methanesulfonic acid (MSA)–tetrahydrofuran (THF)–H2O system with cyanuric acid as the main degradation product. The SEM results showed that the degradation of MFRs followed different reaction mechanisms when H2O and THF were applied as solvents, respectively. The combination of the two solvents showed an obvious synergistic effect for the degradation of MFRs. The degradation experimental results with melamine as the model intermediate indicated that the degradation of MFRs proceeded via the selective cleavage of the sp2C–sp3N and sp3C–sp3N bonds to recover valuable C and N alternated-aromatic ring (CNAR) units, followed by their transformation into a valuable chemical of cyanuric acid. [ABSTRACT FROM AUTHOR]

The essential role of boronic esters in controlling both the direction and selectivity of chemical reactions as well as their significant function in catalytic activity have been demonstrated for industrially important processes. The specific interaction analyses of the monosaccharide GlcNH2 with boric acid are of interest since monosaccharides serve as model systems for the more sophisticated carbohydrate molecules. The interaction of GlcNH2 with boric acid was systematically investigated by numerous NMR techniques. A 1 : 1 chelate boron complex coordinated at the cis-1,2 position of GlcNH2 was identified as the major species in DMSO-d6 solution via1H and 13C INEPT DOSY NMR spectroscopy. This specific boron nitrogen coordination mechanism was further supported by the 1H–15N HSQC spectra. Variations in the spin–lattice relaxation times (T1) of the 13C1 nucleus also provided quantitative data regarding this non-covalent interactions. This is an application of 1H, 13C INEPT DOSY, 1H–15N HSQC, and relaxation methods to study such aggregations in solutions. These methods have potential applications in the characterization of reactive intermediates in biomass conversions. [ABSTRACT FROM AUTHOR]

Liquid phase dehydration of glycerol to acrolein commonly suffers from a low acrolein yield because of severe side reactions of chemically active acrolein with itself or glycerol in the reaction system. Rapid separation of acrolein from the reaction system is one of the effective strategies to increase the yield of acrolein. Herein, a renewable water-in-oil Pickering emulsion with silica nanoparticle cages as microreactors was designed for liquid phase glycerol dehydration to acrolein. The influences of the oil phase types on the droplet size of the Pickering emulsion and the yield of acrolein were investigated in a microreactor. The smaller Pickering emulsion droplet showed a superior ability to intensify the separation of chemically unstable acrolein molecules from the nanoparticle cages and thus improved the yield of acrolein. A droplet size of about 11 μm was obtained with peony seed oil as the oil phase, in which 84.6% of acrolein yield was achieved. [ABSTRACT FROM AUTHOR]

Spinal cord injury (SCI), especially complete transected SCI, leads to loss of cells and extracellular matrix and functional impairments. In a previous study, we transplanted adult spinal cord tissues (aSCTs) to replace lost tissues and facilitate recovery in a rat SCI model. However, rodents display considerable differences from human patients in the scale, anatomy and functions of spinal cord systems, and responses after injury. Thus, use of a large animal SCI model is required to examine the repair efficiency of potential therapeutic approaches. In this study, we transplanted allogenic aSCTs from adult dogs to the lesion area of canines after complete transection of the thoracic spinal cord, and investigated the long-term cell survival and functional recovery. To enhance repair efficiency, a growth factor cocktail was added during aSCT transplantation, providing a favorable microenvironment. The results showed that transplantation of aSCTs, in particular with the addition of growth factors, significantly improves locomotor function restoration and increases the number of neurofilament-, microtubule-associated protein 2-, 5-hydroxytryptamine-, choline acetyltransferase- and tyrosine hydroxylase-positive neurons in the lesion area at 6 months post-surgery. In addition, we demonstrated that donor neurons in aSCTs can survive for a long period after transplantation. This study showed for the first time that transplanting aSCTs combined with growth factor supplementation facilitates reconstruction of injured spinal cords, and consequently promotes long lasting motor function recovery in a large animal complete transected SCI model, and therefore could be considered as a possible therapeutic strategy in humans. [ABSTRACT FROM AUTHOR]

The existing triacetylglycerol (TAG) production method involves esterification of oil (fat)-derived glycerol with acetic acid, forming a mixture of mono-, di- and tri- acetylglycerols. Herein, a new acyl exchange reaction is developed to directly and efficiently produce TAG from waste oils and fats by the driving effect of substituent size changes. Small-sized acetic acids easily replace large long-chain fatty acids of oils. This release in the intramolecular tension and diminishing of steric hindrance make TAG both thermodynamically and dynamically the most favorable product. Pure TAG was obtained with a high yield of 94.9%. [ABSTRACT FROM AUTHOR]

Restoring blood supply is an effective way for the therapy of myocardial infarction (MI). It was reported a specific angiogenic peptide (VMP) derived from vascular endothelial growth factor (VEGF) could activate its receptor to mimic the biological activity of VEGF. In this study, in order to improve the local concentration in infarction region, a collagen‐binding domain was synthesized with VMP to construct collagen binding domain (CBD)‐VMP peptides. The fused CBD‐VMP could bind specifically to collagen which was rich in cardiac extracellular matrix (c‐ECM), without impacting the biological activity of VMP peptides. When the CBD‐VMP peptides loaded on collagen scaffold and implanted into the rats subcutaneously, significant vascularization was observed. Then, CBD‐VMP peptides binding with injectable c‐ECM injected into the MI rat by intramuscular administration, significant blood vessels regeneration, and decrease of cell apoptosis were observed, that corelated with the recovery of cardiac function. It might be an alternative promising strategy for the clinical application of MI. [ABSTRACT FROM AUTHOR]

The combination of benzoic acid and 2,2,6,6-teramethylpiperidin-1-oxyl (TEMPO) afforded an efficient catalytic system for the aerobic oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-diformylfuran (DFF) under certain conditions. The maximum conversion of 86.7 % for HMF was obtained with a nearly 77.8 % DFF yield at 1 mmol benzoic acid and 0.4 MPa oxygen pressure in acetonitrile. The aerobic oxidation ability of HMF into DFF depended on the electron density of the organic acid skeletal structure with the carboxyl group. Meanwhile, the catalyst system of benzoic acid/TEMPO also exhibited good performance for aerobic oxidation of other alcohols. Based on experimental results, we propose that the benzoic acid acted as the primary catalyst and TEMPO was the key co-catalyst, oxidized into oxoammonium cation through electron transport and then regenerated by a superoxide radical during the reaction. [ABSTRACT FROM AUTHOR]

Low temperature 1H- and 19F-DOSY have been used for analyzing reactive intermediates in glycosylation reactions, where a glycosyl trichloroacetimidate donor has been activated using different catalysts. The DOSY protocols have been optimized for low temperature experiments and provided new insight into acid catalyzed glycosylation chemistry. From the study a new glycosylation intermediate was characterized. [ABSTRACT FROM AUTHOR]

This research focuses on high-value utilization of the lignin-derived phenol monomer and bioethanol from biorefining process. Supported-heteropolyacid is easily used as an efficient catalyst for the ethylation of phenol with bioethanol to obtain value-added products. Through adjusting the loading amount, different acidity amount and strength can be obtained, leading to the tunable selectivity to the phenol ethylation route and regioselectivity. [ABSTRACT FROM AUTHOR]

Selective cleavage of C–O–C bonds in lignin without disrupting the C–C linkages can result in releasing aromatic monomers and dimers that can be subsequently converted into chemicals and fuels. Results from this study showed that both biomass-derived lignin and lignin model compounds were depolymerized in a highly concentrated ZnCl2 solution under relatively mild conditions (120 °C–200 °C, 4–6 h). Zn2+ ions in highly concentrated ZnCl2 aqueous solutions appeared to selectively coordinate with C–O–C bonds to cause the key linkages of lignin to be much easier to cleave under mild conditions. In a 63 wt% ZnCl2 solution at 200 °C for 6 h, nearly half of the softwood technical lignin was converted to oil products, of which the majority were alkylphenols. Results indicated that most of the β-O-4 and Cmethyl–OAr bonds of the lignin model compounds were cleaved under the above reaction conditions, providing a foundation towards understanding lignin depolymerization in a concentrated ZnCl2 solution. Furthermore, by adding Ru/C as a co-catalyst, the phenolic products were further converted into more stable cyclic hydrocarbons via hydrodeoxygenation and coupling reactions. [ABSTRACT FROM AUTHOR]

The direct synthesis of 2,5-diformylfuran (DFF) from fructose is a tandem reaction that typically involves two steps catalyzed by two different catalysts, including fructose dehydration to 5-hydroxymethylfurfural (HMF) catalyzed by an acid catalyst and subsequent HMF oxidation to DFF catalyzed by a redox catalyst. In this study, graphene oxide, a metal-free carbon based material, was demonstrated to be an efficient and recyclable bifunctional catalyst in the direct synthesis of DFF from fructose. A DFF yield of 53.0% was achieved in a one pot and one-step reaction (O2, 24 h) and the DFF yield could be further increased to 72.5% in a one pot and two-step reaction (N2, 2 h and O2 22 h). [ABSTRACT FROM AUTHOR]

To advance the “bottom-up” approaches for bone tissue engineering, we developed rat bone mesenchymal stem cell (BMSC)-gelatin microspheres (BGMs) as cell-culture modules and collagen binding domain-bone morphogenetic protein2 (CBD-BMP2)-collagen microcarriers (CCMs) as differentiation-control modules. BMSCs were efficiently seeded onto gelatin microspheres in a spinner flask to form BGMs with a high cell density. CBD-BMP2 was recombined and bound with collagen microfibers to form CCMs, in which BMP2 was controllably released. BGM and CCM were assembled as building blocks to fabricate macroscopic bone-like constructs in vitro and in vivo, where BMSCs were directly induced to differentiate into osteocytes. The osteogenic differentiation of BMSCs was confirmed with increasing mineral deposition (alkaline phosphatase stain, alizarin red stain, calcium content and micro-CT), gene expression of osteogenic markers (alkaline phosphatase, bone sialoprotein, osteocalcin and collagen type I) as well as alkaline phosphatase activity. The in vivo formed bone-like tissues had the compression modulus of 2.62 ± 1.41 MPa, similar to that in the in vivo bone tissues, much higher than those in BGM samples of 0.03 ± 0.012 MPa. Our results suggesting these proof-of-concept strategies, assembling cell-culture modules and function-control modules to modularly engineer clinical-relevant large tissue replacements, have great potential applications in tissue engineering. [ABSTRACT FROM AUTHOR]

The basic ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]) could efficiently catalyze the conversion of 2-amino-2-deoxy-d-glucose (GlcNH2) into deoxyfructosazine (DOF) and fructosazine (FZ). Mechanistic investigation by NMR studies disclosed that [C2C1Im][OAc], exhibiting strong hydrogen bonding basicity, could coordinate with the hydroxyl and amino groups of GlcNH2via the promotion of hydrogen bonding in bifunctional activation of substrates and further catalyzing product formation, based on which a plausible reaction pathway involved in this homogeneous base-catalyzed reaction was proposed. Hydrogen bonding as an activation force, therefore, is responsible for the remarkable selectivity and rate enhancement observed. [ABSTRACT FROM AUTHOR]

An efficient strategy has been developed for chemical recycling of unsaturated polyester resin (UPR) and its glass fibre reinforced polymer composites (GFRP) by selectively cleaving C–O bonds using the AlCl3/CH3COOH system. AlCl3 promotes acyl exchange reaction between CH3COOH and UPR. This process facilitates recovery of valuable oligomers and monomers from UPR, and glass fibres from GFRP. [ABSTRACT FROM AUTHOR]

The incompletely coordinated zinc ions in water enable the cleavage of R2C(secondary carbon)–N bonds without breaking the C–O (aromatic ether) and C–C bonds in carbon fiber/epoxy resin composites. This selective cleavage of C–N bonds favors the recovery of valuable carbon fiber and the basic carbon unit of epoxy resin from their waste composites. [ABSTRACT FROM AUTHOR]

Extrahepatic bile duct ( EBD) injury can happen during surgery. To repair a defect of the EBD and prevent postoperative biliary complications, a collagen membrane was designed. The collagen material was porous, biocompatible, and degradable and could maintain its shape in bile soaking for about 4 weeks. The goal was to induce rapid bile duct tissue regeneration. Twenty Chinese experimental hybrid pigs were used in this study and divided into a patch group and a control group. A spindle-shaped defect (20 mm × 6 mm) was made in the anterior wall of the lower EBD in the swine model, and then the defect was reconstructed using a collagen patch with a drainage tube and wrapped with greater omentum. Ultrasound was performed at 2, 4, 8, and 12 weeks postoperatively. Liver function tests and white blood cell count ( WBC) were measured. Hematoxylin-eosin staining, cytokeratin 7 immunohistochemical staining, and Van Gieson's staining of EBD were used. The diameter and thickness of the EBD at the graft site were measured. There was no significant difference in liver function tests or WBC in the patch group compared with the control group. No evidence of leakage or stricture was observed, but some pigs developed biliary sludge or stone at 4 and 8 weeks. The drainage tube was lost within 12 weeks. The neo- EBD could withstand normal biliary pressure 2 weeks after surgery. Histological study showed the accessory glands and epithelial cells gradually regenerated at graft sites from 4 weeks, with increasing vessel infiltration and decreasing inflammation. The collagen fibers became regular with full coverage of epithelial cells. The statistical analysis of diameter and thickness showed no stricture formation at the graft site, but the EBD wall was slightly thicker than in the normal bile duct due to collagen fiber deposition. The structure of the neo- EBD was similar to that of the normal EBD. The collagen membrane patch associated with a drainage tube and wrapped with greater omentum effectively induced the regeneration of the EBD defect within 12 weeks. [ABSTRACT FROM AUTHOR]

Bone morphogenetic protein-2 (BMP-2) is a potent osteoinductive cytokine that plays a critical role in bone regeneration and repair. However, its distribution and side effects are major barriers to its success as therapeutic treatment. The improvement of therapy using collagen delivery matrices has been reported. To investigate a delivery system on postero-lateral spinal fusion, both engineered human BMP-2 with a collagen binding domain (CBD-BMP-2) and collagen scaffolds were developed and their combination was implanted into Sprague-Dawley (SD) rats to study Lumbar 4–5 (L4–L5) posterolateral spine fusion. We divided SD rats into three groups, the sham group (G1, n = 20), the collagen scaffold-treated group (G2, n = 20) and the BMP-2-loaded collagen scaffolds group (G3, n = 20). 16 weeks after surgery, the spines of the rats were evaluated by X-radiographs, high-resolution micro-computed tomography (micro-CT), manual palpation and hematoxylin and eosin (H&E) staining. The results showed that spine L4–L5 fusions occurred in G2(40%) and G3(100%) group, while results from the sham group were inconsistent. Moreover, G3 had better results than G2, including higher fusion efficiency (X score, G2 = 2.4±0.163, G3 = 3.0±0, p<0.05), higher bone mineral density (BMD, G2: 0.3337±0.0025g/cm3, G3: 0.4353±0.0234g/cm3. p<0.05) and more bone trabecular formation. The results demonstrated that with site-specific collagen binding domain, a dose of BMP-2 as low as 0.02mg CBD-BMP-2/cm3 collagen scaffold could enhance the posterolateral intertransverse process fusion in rats. It suggested that combination delivery could be an alternative in spine fusion with dramatically decreased side effects caused by high dose of BMP-2. [ABSTRACT FROM AUTHOR]

The design of green heterogeneous catalysts for the efficient conversion of biomass into platform molecules is a key aim of sustainable chemistry. Graphene oxide prepared from Hummers oxidation of graphite was proven to be a green and efficient carbocatalyst for the dehydration of fructose into 5-hydroxymethylfurfural (HMF) in some three-carbon and four-carbon alcohol mediated solvent systems. HMF was obtained in up to 87 % yield in 90 vol % isopropanol-mediated DMSO solvent. Some control experiments and analytical data showed that a small number of sulfonic groups and abundance of oxygen-containing groups (alcohols, epoxides, carboxylates) have an important synergic effect in maintaining the high performance of graphene oxide. [ABSTRACT FROM AUTHOR]

Nerve conduit is one of strategies for spine cord injury (SCI) treatment. Recently, studies showed that biomaterials could guide the neurite growth and promote axon regeneration at the injury site. However, the scaffold by itself was difficult to meet the need of SCI functional recovery. The basic fibroblast growth factor (bFGF) administration significantly promotes functional recovery after organ injuries. Here, using a rat model of T9 hemisected SCI, we aimed at assessing the repair capacity of implantation of collagen scaffold (CS) modified by collagen binding bFGF (CBD-bFGF). The results showed that CS combined with CBD-bFGF treatment improved survival rates after the lateral hemisection SCI. The CS/CBD-bFGF group showed more significant improvements in motor than the simply CS-implanted and untreated control group, when evaluated by the 21-point Basso-Beattie-Bresnahan (BBB) score and footprint analysis. Both hematoxylin and eosin (H&E) and immunohistochemical staining of neurofilament (NF) and glial fibrillary acidic protein (GFAP) demonstrated that fibers were guided to grow through the implants. These findings indicated that administration of CS modified with CBD-bFGF could promote spinal cord regeneration and functional recovery. [ABSTRACT FROM AUTHOR]

Graphene oxide obtained by the Hummers method was discovered to be an efficient and recyclable acid catalyst for the conversion of fructose-based biopolymers into 5-ethoxymethylfurfural (EMF). EMF yields of 92%, 71%, 34% and 66% were achieved when 5-hydroxymethylfurfural (HMF), fructose, sucrose and inulin were used as starting materials, respectively. [ABSTRACT FROM AUTHOR]

In the present study, the process of separation and purification of isohamnetin from marc of sea buckthorn was obtained. The antioxidant properties of the pure isolated isorhamnetin were evaluated by the scavenging of the diphenylpicrylhydrazyl radical (DPPH), iron (III) to iron (II)—reducing, and iron-chelating assays. High purity isorhamnetin (92.1%) was obtained and the results of antioxidant assays showed that isorhamnetin performed significantly compared with ascorbic acid and BHT, and the linear correlations were good in these assays. In conclusion, isorhamnetin may have potential as a natural antioxidant to alternate synthetic substances as food additive with its antioxidant activity. [ABSTRACT FROM AUTHOR]

Lewis acid catalysts are active for both esterification and transesterification, but the reaction is very slow due to mass-transfer limitations between methanol and oil phase. Because oil, FFA and Lewis acid catalysts are all soluble in the subcritical methanol phase, the esterification and transesterification will be enhanced when they are carried out under subcritical conditions. In this work, the esterification and transesterification of high FFA oil to biodiesel via Lewis acid catalysts such as Pb(OOCCH3)2, Cd(OOCCH3)2 and Zn(OOCCH3)2 were carried out in the subcritical methanol phase (2 MPa, 180°C, reaction time 30 min). The results show that the esterification conversion reaches 79.8-96.4% with Palmitic acid as feedstock, and the transesterification conversion reaches 56.8-73.4% with soybean oil as feedstock. With the mixture of Soybean oil and Palmitic acid (FFA content of 20.3 wt%) as feedstock, the content of fatty acid methyl esters (FAME) in products reaches 67.3-83.4%. [ABSTRACT FROM AUTHOR]

The microenvironment plays a pivotal role for cell survival and functional regulation, and directs the cell fate determination. The biological functions of DCs have been extensively investigated to date. However, the influences of the microenvironment on the differentiation of bone marrow cells (BMCs) into dendritic cells (DCs) are not well defined. Here, we established a 3D collagen scaffold microenvironment to investigate whether such 3D collagen scaffolds could provide a favourable niche for BMCs to differentiate into specialised DCs. We found that BMCs embedded in the 3D collagen scaffold differentiated into a distinct subset of DC, exhibiting high expression of CD11b and low expression of CD11c, co-stimulator (CD40, CD80, CD83, and CD86) and MHC-II molecules compared to those grown in 2D culture. DCs cultured in the 3D collagen scaffold possessed weak antigen uptake ability and inhibited T-cell proliferation in vitro; in addition, they exhibited potent immunoregulatory function to alleviate allo-delay type hypersensitivity when transferred in vivo. Thus, DCs differentiated in the 3D collagen scaffold were defined as regulatory DCs, indicating that collagen scaffold microenvironments probably play an important role in modulating the lineage commitment of DCs and therefore might be applied as a promising tool for generation of specialised DCs. [ABSTRACT FROM AUTHOR]

Correction for ‘Centimeter-sized biomimetic bone constructs fabricated via CBD-BMP2-collagen microcarriers and BMSC-gelatin microspheres’ by Depeng Kou et al., J. Mater. Chem. B, 2016, 4, 461–470. [ABSTRACT FROM AUTHOR]