Interleukin-6 promotes skeletal muscle catabolism by activating tryptophan-indoleamine 2,3-dioxygenase 1-kynurenine pathway during intra-abdominal sepsis.

BACKGROUND: Inflammatory cytokine interleukin-6 (IL-6) plays a pivotal role in skeletal muscle degradation after intra-abdominal sepsis (IAS), with mechanism remained to be elucidated. Indoleamine 2,3-dioxygenase 1 (IDO-1), a key enzyme in converting tryptophan into kynurenine, could be activated by IL-6, and kynurenine has been shown to be involved in muscle degradation. We hypothesized that IL-6 could promote muscle degradation via tryptophan-IDO-1-kynurenine pathway in IAS patients. METHODS: Serum and rectus abdominis (RA) were obtained from IAS or non-IAS patients. Mouse model of IAS-induced muscle wasting was generated by caecal ligation and puncture (CLP) and lipopolysaccharide (LPS) injection. IL-6 signalling was blocked by anti-mouse IL-6 antibody (IL-6-AB), and the IDO-1 pathway was blocked by navoximod. To elucidate the role of kynurenine in muscle mass and physiology, kynurenine was administered to IAS mice treated with IL-6-AB. RESULTS: Compared to non-IAS patients, kynurenine levels in serum (+2.30-fold vs. non-IAS, P < 0.001) and RA (+3.11-fold vs. non-IAS, P < 0.001) were elevated, whereas tryptophan levels in serum (-53.65% vs. non-IAS, P < 0.01) and RA (-61.39% vs. non-IAS, P < 0.01) were decreased. Serum IL-6 level of the IAS group was significantly higher compared to non-IAS patients (+5.82-fold vs. non-IAS, P = 0.01), and muscle cross-sectional area (MCSA) was markedly reduced compared to non-IAS patients (-27.73% vs. non-IAS, P < 0.01). In animal experiments, IDO-1 expression was up-regulated in the small intestine, colon and blood for CLP or LPS-treated mice, and there was correlation (R2  = 0.66, P < 0.01) between serum and muscle kynurenine concentrations. Navoximod significantly mitigated IAS-induced skeletal muscle loss according to MCSA analysis (+22.94% vs. CLP, P < 0.05; +23.71% vs. LPS, P < 0.01) and increased the phosphorylated AKT (+2.15-fold vs. CLP, P < 0.01; +3.44-fold vs. LPS, P < 0.01) and myosin heavy chain (+3.64-fold vs. CLP, P < 0.01; +2.13-fold vs. LPS, P < 0.01) protein expression in myocytes. In the presence of anti-IL-6 antibody, a significantly decreased IDO-1 expression was observed in the small intestine, colon and blood in CLP or LPS mice (all P < 0.01), whereas the decrease of MCSA was alleviated (+37.43% vs. CLP + IgG, P < 0.001; +30.72% vs. LPS + IgG, P < 0.001). In contrast, additional supplementation of kynurenine decreased the MCSA in septic mice treated with IL-6-AB (both P < 0.01). CONCLUSIONS: This study provided novel insights into the tryptophan-IDO-1-kynurenine-dependent mechanisms that underlie inflammatory cytokine-induced skeletal muscle catabolism during intra-abdominal sepsis.

Establishment of an overactive bladder model in mice.

BACKGROUND: Overactive bladder (OAB) is a syndrome characterized by symptoms of urinary urgency, often accompanied by frequent urination and nocturia or urge incontinence. METHODS: Twenty female ICR mice were randomly divided into pBOO (partial bladder outlet obstruction) and control groups. The mouse OAB model was constructed by ligating the bladder outlet. Eight weeks after the operation, the methods of voiding spot on paper (VSOP), isolated detrusor muscle, and HE staining were used for analysis and research. RESULTS: After the operation, two mice in the experimental and one in control died, and one in the control groups had an abnormal bladder size, so it was excluded from the statistical analysis. Eight weeks after the operation, there was an insignificant difference (P = 0.15) in the body weight of mice in the pBOO (26.54 ± 2.62 g) and the control group (24.84 ± 1.76 g). The number of urinations in 12 h was significantly higher (P < 0.001) in the pBOO (7.63 ± 1.19) than in the control group (4.13 ± 0.99). Also, the 12-h urine volume of pBOO (1491.23 ± 94.72 µL) was significantly greater (P = 0.006) than that of the control group (1344.86 ± 88.17 µL). The isolated bladder of the pBOO mice was significantly heavier than that in the control group (53.16 ± 1.79 mg vs. 24.54 ± 1.80 mg, P < 0.001), the horizontal and vertical length of the bladder in pBOO group were larger than those in the control group (P < 0.001). The detrusor thickness of pBOO group (357.50 ± 11.88 µm) was significantly thicker than that of control group (258.52 ± 17.22 µm, P < 0.001), and the isolated muscle strip was more sensitive to carbachol stimulation. According to HE staining, the bladder wall of the pBOO mice was significantly thickened. CONCLUSIONS: A pBOO-mediated mouse OAB model was successfully established by ligating the bladder outlet.

Can reduced-input direct seeding improve resource use efficiencies and profitability of hybrid rice in China?

The mechanization of rice production in China has been accompanied by a rapid reduction in agricultural labor forces and increase in machinery purchase subsidies; however, the comprehensive performance of several major mechanized production modes regarding output, environmental protection, and profit remains uncertain to the Chinese government and farmers alike. Here, a five-year (2015-2019) field experiment was conducted to analyze the performance of farmers' mechanized seedling transplanting (FMST), farmers' mechanized direct seeding (FMDS), and reduced-input direct seeding (RIDS) concerning grain yield, energy use, greenhouse gas emissions, and economic benefits. RIDS used an unmanned aerial vehicle for sowing, fertilizing, and spraying, while adopting no-tillage, bed-furrow irrigation technology. The quantity and stability of RIDS-produced grain were similar to those of FMST and higher than those of FMDS. Furthermore, RIDS yields required significantly less machinery, human labor, fuel, and water, with 34.72% and 24.03% decreases in total energy input compared to that for FMST and FMDS, corresponding to 1.45- and 1.34-fold increases in energy productivity, respectively. The resulting CO2-eq emissions from agricultural inputs for RIDS were 71.26% and 71.32% of those for FMST and FMDS, while CH4 emissions were 32.60% and 29.24% of those for FMST and FMDS, respectively. Despite the high N2O emissions and decomposing trend of soil organic carbon in RIDS, the net global warming potential still decreased by 48.84-58.36%, and the carbon sustainability index and carbon efficiency ratio increased by 87.67-142.14% and 105.32-188.22%, respectively, compared with those of FMST and FMDS. RIDS had the lowest cost, its net return was USD 298.81 ha-1 higher than that of FMDS (similar to FMST), and its benefit-cost ratio was 10-36.19% higher than that of FMST and FMDS. Generally, RIDS offered a higher-yielding, cleaner, more sustainable rice production technology for meeting the needs of the Chinese government and farmers.

Perioperative parenteral fish oil supplementation improves postoperative coagulation function and outcomes in patients undergoing colectomy for ulcerative colitis.

OBJECTIVE: Ulcerative colitis (UC) is an independent risk factor for thromboembolism, especially during the perioperative period. This study aimed to determine the effects of perioperative parenteral nutrition (PN) supplemented with fish oil (FO) on coagulation function and postoperative outcomes in patients with UC. METHODS: This retrospective cohort included 92 consecutive patients who underwent colectomy for UC. Postoperative coagulation indices and outcomes, including thromboelastography (TEG) findings and comprehensive complication index (CCI), were compared. The relative change in serum D-dimer (ΔD-dimer) levels and maximal amplitude (ΔMA) on TEG were also determined. RESULTS: Patients receiving PN supplemented with FO (n = 48) had lower D-dimer (P = .036) levels on postoperative day (POD) 5 and a higher MA (P < 0.001) on POD 1 than those who did not receive it (n = 44). A lower ΔD-dimer level (P = .048) and ΔMA (P < 0.001) were also observed in patients receiving FO. The incidence of major postoperative complications (6.3 vs 22.7%; P = .017) and CCI (20.9 vs 23.4%; P = .044) were significantly lower in patients receiving FO. In multivariate analysis, FO (odds ratio, 0.231; 95% confidence interval, 0.055-0.971; P = .046) was a positive protector of major postoperative complications. CONCLUSION: Perioperative PN supplemented with FO improved coagulation function and reduced major postoperative complications in patients with UC requiring colectomy. These results may provide cues in formulating management strategies for preventing thromboembolisms and postoperative complications in patients with UC.

Protein2Vec: Aligning Multiple PPI Networks with Representation Learning.

Research of Protein-Protein Interaction (PPI) Network Alignment is playing an important role in understanding the crucial underlying biological knowledge such as functionally homologous proteins and conserved evolutionary pathways across different species. Existing methods of PPI network alignment often try to improve the coverage ratio of the alignment result by aligning all proteins from different species. However, there is a fundamental biological premise that needs to be considered carefully: not every protein in a species can, nor should, find its homologous proteins in other species. In this work, we propose a novel alignment method to map only those proteins with the most similarity throughout the PPI networks of multiple species. For the similarity features of the protein in the networks, we integrate both topological features with biological characteristics to provide enhanced supports for the alignment procedures. For topological features, we apply a representation learning method on the networks and generate a low dimensional vector embedding with its surrounding structural features for each protein. The topological similarity of proteins from different PPI networks can thus be transferred as the similarity of their corresponding vector representations, which provides a new way to comprehensively quantify the topological similarities between proteins. We also propose a new measure for the topological evaluation of the alignment results which better uncover the structural quality of the alignment across multiple networks. Both biological and topological evaluations on the alignment results of real datasets demonstrate our approach is promising and preferable against previous multiple alignment methods.

In-Situ Growth of Broussonetia-Like NiCo2O4 on Carbon Cloth with Tailored Aqueous Capacitance.

Tailored broussonetia-like NiCo2O4 is grown on carbon cloth using tri-sodium citrate assisted hydrothermal method. The chelating effect of citric ions has been utilized to investigate the morphological and structural evolution of NiCo2O4 on carbon cloth, which have been illustrated by scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectra. The results demonstrate that the morphological alteration of NiCo2O4 from single nanowire to broussonetia-like structure has been detected after the addition of tri-sodium citrate. Citric ion plays a crucial role as an electrostatic stabilizer in determining this unique structure. When used as binder-free electrode in aqueous supercapacitors, the broussonetia-like NiCo2O4 electrode exhibits a specific capacitance of 527.9 F g-1 at a current density of 0.5 A g-1. Additionally, an asymmetric supercapacitor is further assembled using NiCo2O4 as the positive electrode and activated carbon as negative electrode. The device exhibits a maximum energy of 26.4 Wh kg-1 at power density of 800 W kg-1. A long-term cycling stability with 82% capacitance retention is maintained after 20,000 cycles at a current density of 5 A g-1, indicating the practical applicability of the tested device.

Morphophysiological mechanism of rice yield increase in response to optimized nitrogen management.

The yield-increasing mechanism of an optimized nitrogen fertilizer application (OFA) in rice was reported in this work through a three-year test. Results showed that the number of branches and spikelets increased, panicle length, the diameter and vascular bundle number of panicle-neck internode improved with OFA. Under the condition of OFA, high effective leaf areas, especially for the flag and the second upper leaf areas, increased, the net photosynthetic rate of the upper three leaves promoted, so the photosynthetic productivity went up by a large margin; moreover, the content of soluble protein and chlorophyll of leaf also increased, and the content of soluble sugar and malondialdehyde (MDA) decreased, as a result in slowing down the senescence speed in leaves, and increasing the photosynthetic time. Gene expression level, including MOC1, LAX1, SP1, GS1;1, were up-regulated obviously in different panicle initiation stage under OFA condition, which conduced to the increase in the secondary branches and spikelets. So we concluded that the changes in organ formation and panicle structure, together with the responses in physiological and molecular made the photosynthetic area, rate and time all increased with OFA, which provided the matter basis for the big panicle development, consequently, got a higher yield.

Fecal calprotectin as an alternative to ulcerative colitis endoscopic index of severity to predict the response to corticosteroids of acute severe ulcerative colitis: A prospective observational study.

BACKGROUND: Fecal calprotectin (FC) might be an alternative to ulcerative colitis endoscopic index of severity (UCEIS) to predict the response to corticosteroids (CS) in acute severe colitis (ASC). METHODS: One hundred and seventeen ASC patients were prospectively enrolled. Demographic, clinical, laboratory and sigmoidoscopic data were documented. Multivariate and ROC analyses were performed to identify risk factors for non-response to CS, and the predictive accuracy of possible predictors was assessed. RESULTS: Totally, 39 (33.33%) patients failed intravenous CS therapy. CS responders among mild (UCEIS 3-4), moderate (UCEIS 5-6) and severe (UCEIS 7-8) groups were 40/44 (90.91%) vs. 36/55 (65.45%) vs. 2/18 (11.11%) (p<0.001). UCEIS (OR=5.08; 95% CI, 1.93-8.66; p<0.001) and FC (OR=2.56; 95% CI, 1.17-3.55; p=0.022) were found to be independent risk factors for CS non-responders. Compared with C-reactive protein, platelet, hemoglobin and albumin, baseline FC had the strongest correlation with UCEIS (r=0.701, p<0.001). ROC analysis of UCEIS and baseline FC in predicting CS non-response showed an AUC of 0.85 and 0.76 respectively. CONCLUSIONS: Baseline FC levels correlated significantly with UCEIS in ASC, and both were useful in predicting short-term outcome of CS treatment. Baseline FC levels could be used as an alternative of UCEIS to guide the decision of early salvage therapy or colectomy and reduce the adverse effects of long-term futile CS usage.

Soluble Dietary Fiber Ameliorates Radiation-Induced Intestinal Epithelial-to-Mesenchymal Transition and Fibrosis.

BACKGROUND: Intestinal fibrosis is a late complication of pelvic radiotherapy. Epithelial-to-mesenchymal transition (EMT) plays an important role in tissue fibrosis. The aim of this study was to examine the effect of soluble dietary fiber on radiation-induced intestinal EMT and fibrosis in a mouse model. MATERIALS AND METHODS: Apple pectin (4% wt/wt in drinking water) was administered to wild-type and pVillin-Cre-EGFP transgenic mice with intestinal fibrosis induced by a single dose of abdominal irradiation of 10 Gy. The effects of pectin on intestinal EMT and fibrosis, gut microbiota, and short-chain fatty acid (SCFA) concentration were evaluated. RESULTS: Intestinal fibrosis in late radiation enteropathy showed increased submucosal thickness and subepithelial collagen deposition. Enhanced green fluorescent protein (EGFP)+/vimentin+ and EGFP+/α-smooth muscle actin (SMA)+ coexpressing cells were most clearly observed at 2 weeks after irradiation and gradually decreased at 4 and 12 weeks. Pectin significantly attenuated the thickness of submucosa and collagen deposition at 12 weeks (24.3 vs 27.6 µm in the pectin + radiation-treated group compared with radiation-alone group, respectively, P < .05; 69.0% vs 57.1%, P < .001) and ameliorated EMT at 2 and 4 weeks. Pectin also modulated the intestinal microbiota composition and increased the luminal SCFA concentration. CONCLUSION: The soluble dietary fiber pectin protected the terminal ileum against radiation-induced fibrosis. This effect might be mediated by altered SCFA concentration in the intestinal lumen and reduced EMT in the ileal epithelium.

Skeletal muscle depletion correlates with disease activity in ulcerative colitis and is reversed after colectomy.

BACKGROUND & AIMS: The body composition of patients with ulcerative colitis (UC) remains unclear. This study evaluated body composition in adult patients with UC and the associations of body composition with disease activity and surgical intervention. METHODS: This study included 99 patients with UC, 105 with Crohn's disease (CD) and 60 controls. Skeletal muscle area (SMA), visceral fat area (VFA) and subcutaneous fat area (SFA) of the third lumbar vertebrae were evaluated by abdominal computed tomography. The effects of medical therapy and surgery on body composition in UC patients were determined. RESULTS: Sarcopenia was more frequent in UC patients (27.3%) than in controls (8.3%), but less frequent than in CD patients (59.0%). The prevalence of sarcopenia was significantly higher (33.8% vs. 4.5%, p < 0.001), and SMA (144.26 vs. 182.32 cm2, p < 0.001), skeletal muscle index (SMI) (52.22 vs. 65.52 cm2/m2, p < 0.001) significantly lower, in UC patients with high (≥6) than low (<6) Mayo score, but SFA and VFA were similar. The prevalence of sarcopenia and alterations in body composition were reversed, along with UC disease activity, following medical treatment or surgery. SMA and SMI correlated significantly with disease activity in UC patients. Multivariate analysis showed that sarcopenia (odds ratio, 8.49; 95% confidence interval, 1.80-40.10; p = 0.007) was a negative predictor of high Mayo score in UC patients. Sarcopenic patients with UC had high probability of need for colectomy in Kaplan-Meier survival curves. CONCLUSIONS: Sarcopenia is associated with high disease activity and poor clinical outcome in UC patients. Medical treatment and colectomy have positive effects on sarcopenia and skeletal muscle depletion.

Clinical features, outcome and risk factors in cervical cancer patients after surgery for chronic radiation enteropathy.

BACKGROUND: Radical hysterectomy and radiotherapy have long been mainstays of cervical cancer treatment. Early stage cervical cancer (FIGO stage IB1-IIA) is traditionally treated using radical surgery combined with radiotherapy, while locally advanced cervical cancer is treated using radiotherapy alone or chemoradiotherapy. In this retrospective study, we describe and analyse the presenting clinical features and outcomes in our cohort and evaluate possible risk factors for postoperative morbidity in women who underwent surgery for chronic radiation enteropathy (CRE). METHODS: One hundred sixty-six eligible cervical cancer patients who underwent surgery for CRE were retrospectively identified between September 2003 and July 2014 in a prospectively maintained database. Among them, 46 patients received radical radiotherapy (RRT) and 120 received radical surgery plus radiotherapy (RS + RT). Clinical features, postoperative morbidity and mortality, and risk factors for postoperative morbidity were analysed. RESULTS: RS + RT group patients were more likely to present with RTOG/EORTC grade III late morbidity (76.1 % vs 92.5 %; p = 0.004), while RRT group patients tended to show RTOG/EORTC grade IV late morbidity (23.9 % vs 7.5 %; p = 0.004). One hundred forty patients (84.3 %) were treated with aggressive resection (anastomosis 57.8 % and stoma 26.5 %). Overall and major morbidity, mortality and incidence of reoperation in the RRT and RS + RT groups did not differ significantly (63 % vs 64.2 % [p = 1.000], 21.7 % vs 11.7 % [p = 0.137], 6.5 % vs 0.8 % [p = 0.065] and 6.5 % vs 3.3 % [p = 0.360], respectively). However, incidence of permanent stoma and mortality during follow-up was higher in the RRT group than in the RS + RT group (44.2 % vs 12.6 % [p = 0.000] and 16.3 % vs 3.4 % [p = 0.004], respectively). In multivariate analysis, preoperative anaemia was significantly associated with overall morbidity (p = 0.015), while severe intra-abdominal adhesion (p = 0.017), ASA grades III-V (P = 0.022), and RTOG grade IV morbidity (P = 0.018) were predicators of major morbidity. CONCLUSIONS: Radiation-induced late morbidity tended to be severe in the RRT group with more patients suffering RTOG/EORTC grade IV morbidity, while there were no significant differences in postoperative morbidity, mortality and reoperation. Aggressive resection was feasible with acceptable postoperative outcomes. Severe intra-abdominal adhesion, ASA grades III-V and RTOG/EORTC grade IV late morbidity contributed significantly to major postoperative morbidity.

Role of Wnt/ß-Catenin Signaling in Epithelial Differentiation of Lung Resident Mesenchymal Stem Cells.

Accumulating evidence has demonstrated that stem cells have the ability to repair the lung tissue injuries following either injection of cultured cells or bone marrow transplantation. As a result, increasing attention has focused on the lung resident mesenchymal stem cells (LR-MSCs) for repairing damaged lung tissues. Meanwhile, some studies have revealed that Wnt/ß-catenin signaling plays an important role in the epithelial differentiation of mesenchymal stem cells (MSCs). In the current study, our aim was to explore the roles of Wnt/ß-catenin signaling on cell proliferation and epithelial differentiation of LR-MSCs. We have successfully isolated the stem cell antigen (Sca)-1(+) CD45(-) CD31(-) cells which were proposed to be LR-MSCs by magnetic-activated cell sorting (MACS). Furthermore, we demonstrated the expression of epithelial markers on LR-MSCs following indirect co-culture of these cells with alveolar epithelial type II (ATII) cells, confirming the epithelial phenotype of LR-MSCs following co-culture. In order to clarify the regulatory mechanisms of Wnt/ß-catenin signaling in epithelial differentiation of LR-MSCs, we measured the protein levels of several important members involved in Wnt/ß-catenin signaling in the presence or absence of some canonical activators and inhibitors of the ß-catenin pathways. In conclusion, our study demonstrated that Wnt/ß-catenin signaling may be an essential mechanism underlying the regulation of epithelial differentiation of LR-MSCs.

Soil physicochemical and biological properties of paddy-upland rotation: a review.

Paddy-upland rotation is an unavoidable cropping system for Asia to meet the increasing demand for food. The reduction in grain yields has increased the research interest on the soil properties of rice-based cropping systems. Paddy-upland rotation fields are unique from other wetland or upland soils, because they are associated with frequent cycling between wetting and drying under anaerobic and aerobic conditions; such rotations affect the soil C and N cycles, make the chemical speciation and biological effectiveness of soil nutrient elements varied with seasons, increase the diversity of soil organisms, and make the soil physical properties more difficult to analyze. Consequently, maintaining or improving soil quality at a desirable level has become a complicated issue. Therefore, fully understanding the soil characteristics of paddy-upland rotation is necessary for the sustainable development of the system. In this paper, we offer helpful insight into the effect of rice-upland combinations on the soil chemical, physical, and biological properties, which could provide guidance for reasonable cultivation management measures and contribute to the improvement of soil quality and crop yield.

Characteristics of selective fluoride adsorption by biocarbon-Mg/Al layered double hydroxides composites from protein solutions: kinetics and equilibrium isotherms study.

In the study, two novel applied biocarbon-Mg/Al layered double hydroxides composites (CPLDH and CPLDH-Ca) were successfully prepared and characterized by TEM, ICP-AES, XFS, EDS, FTIR, XRD, BET and pHpzc. The fluoride removal efficiency (RF) and protein recovery ratio (RP) of the adsorbents were studied in protein systems of lysozyme (LSZ) and bovine serum albumin (BSA). The results showed that the CPLDH-Ca presented remarkable performance for selective fluoride removal from protein solution. It reached the maximum RF of 92.1% and 94.8% at the CPLDH-Ca dose of 2.0g/L in LSZ and BSA system, respectively. The RP in both systems of LSZ and BSA were more than 90%. Additionally, the RP of CPLDH-Ca increased with the increase of ionic strengths, and it almost can be 100% with more than 93% RF. Fluoride adsorption by the CPLDH-Ca with different initial fluoride concentrations was found to obey the mixed surface reaction and diffusion controlled adsorption kinetic model, and the overall reaction rate is probably controlled by intra-particle diffusion, boundary layer diffusion and reaction process. The adsorption isotherms of fluoride in BSA system fit the Langmuir-Freundlich model well. The BSA has synergistic effect on fluoride adsorption and the degree increased with the increase of the initial BSA concentration.

Physicochemical characterization and sorption behavior of Mg-Ca-Al (NO3) hydrotalcite-like compounds toward removal of fluoride from protein solutions.

The present study explores the potential of Mg-Ca-Al (NO(3)) hydrotalcite-like compounds (MgCaAlNO(3)-HTlcs) for the removal of fluoride from protein solutions. In this study, the Mg(3-x)Ca(x)AlNO(3)-HTlcs (x=0-3, x is the mol.% of Ca) were synthesized and characterized by SEM, XRD, FTIR, BET, ICP-AES and pHzpc analysis. The sorption experiments were conducted in protein systems of bovine serum albumin (BSA) and lysozyme (LSZ). The batch experiment results showed that the NO(3)-HTlc with Mg/Ca/Al molar ratio of 2.5/0.5/1 had remarkable fluoride sorption ability with maximum sorption capacities of 82.35 mg/g and 72.69 mg/g at pH 5.0 and 40°C in BSA and LSZ system, respectively. Moreover, the loss of BSA of 0.71% was low and there was no loss of LSZ. It was evident that the Mg(2.5)Ca(0.5)AlNO(3)-HTlc could selectively adsorb fluoride from protein solutions. The equilibrium sorption data fitted well to the Langmuir model and the kinetic data conformed to the pseudo-second-order model. Thermodynamic parameters (ΔG°, ΔH° and ΔS°) were evaluated and revealed that the sorption process was spontaneous and endothermic in nature. Furthermore, the results from Antarctic krill processing wastewater study confirmed the feasibility and practicality of the Mg(2.5)Ca(0.5)AlNO(3)-HTlc for fluoride removal in fluoride bearing protein system.

Gene-carried chitosan-linked-PEI induced high gene transfection efficiency with low toxicity and significant tumor-suppressive activity.

PEI and chitosan are considered to be promising non-viral gene delivery vectors. To improve the transfection efficiency of chitosan, we linked chitosan with polyethylenimine (PEI, Mw=1.8 kDa) by 1,1'-carbonyldiimidazole to form a complex. The composition, particle size, as well as the zeta potential of this chitosan-linked-PEI (CP) complex were measured. And the DNA binding ability, cytotoxicity, and gene transfection efficiency of CP complex were also investigated in cancer cells. In HepG2, A549 and HeLa cells, CP complex exhibited lower cytotoxicity as compared with PEI25KDa (Mw=25 kDa), a positive control proved to be an efficient gene transfection polymer. Likewise, it showed good transfection efficiency in these cancer cell lines. Specifically, the long-term transfection efficiency of CP was higher than PEI25KDa as demonstrated by the in vitro cancer cell model. The confocal laser scanning microscopy data showed the time for CP to enter the nucleus was 4h, which was longer than that of PEI25KDa but shorter than that of chitosan. Furthermore, CP complexes were used as a gene carrier to deliver the CCL22 gene into H22 cells. When these gene-altered cells were inoculated in mice, the tumor growth rate was significantly decreased, indicating the CP copolymer was a promising vector for the therapeutic gene delivery.

N/P ratio significantly influences the transfection efficiency and cytotoxicity of a polyethylenimine/chitosan/DNA complex.

For designing a complex vector that has the advantages of both polyethylenimine (PEI) and chitosan for gene delivery, a PEI/chitosan/DNA complex was constructed at various N/P ratios (the ratios of moles of the amine groups of cationic polymers to those of the phosphate ones of DNA) and both the cytotoxicity and the transfection efficiency of the vector were evaluated. The results demonstrated that the chitosan/DNA binding degree was depended on the N/P ratio. The mean size of the complex vector was between 100 nm and 150 nm. Compared with PEI/DNA, the complex vector (PEI/chitosan/DNA with chitosan/DNA N/P=4, PEI/DNA N/P=10) appeared to have low cytotoxicity, which maintained the cell survival rate at greater than 80%, and showed higher transfection efficiency of nearly 1000 fold compared with that using chitosan/DNA alone. Furthermore, the expression efficiency of the complex vector carrying enhanced green fluorescent protein was not inhibited in the presence of serum in both HeLa cells and A549 cells. The PEI/chitosan complex may be a promising gene carrier that has high transfection efficiency as well as low cytotoxicity.