Effect of extracellular proteins on Cd(II) adsorption in fungus and algae symbiotic system.

Fungus-algae symbiotic systems (FASS) are typically used to assist in the immobilization of algae and strengthen the adsorption of heavy metals. However, the adsorption behavior of the symbiotic system and the molecular regulation mechanism of extracellular proteins in the adsorption of heavy metals have not been reported in detail. In this study, a stable FCSS (fungus-cyanobacterium symbiotic system) was used to study Cd(II) adsorption behavior. The fixation efficiency of fungus to cyanobacterium reached more than 95% at pH7.0, 30 °C, 150 rpm, and a medium ratio of 100%. The biomass, chlorophyll content, and total fatty acid content of the symbiotic system were much higher than those of cyanobacterium and fungus alone. The photosynthetic fluorescence parameters showed that the presence of fungus enhanced the light tolerance of cyanobacterium. The original light energy conversion efficiency and potential activity of PSII were enhanced, indicating that symbiosis could promote the photosynthetic process of cyanobacterium. The Cd(II) adsorption efficiency can achieve 90%. The system maintained excellent adsorption after six adsorption cycles. Differential proteins were mainly enriched in areas such as metabolism, ABC transport system, and pressure response. Cd(II) stress promotes an increase in efflux proteins. Moreover, cadmium can be fixed as much as possible by secreting extracellular proteins, and the toxicity of cadmium to cells can be alleviated by regulating the metabolism of glutathione, reducing oxidative phosphorylation level, and reducing oxidative stress, thus improving the resistance to Cd(II). Meanwhile, the expression of enzymes involved in glycolysis and the pentose phosphate pathway was upregulated, while the expression of those in the TCA cycle was downregulated. The expression of substances related to PSI and PSII in the photosynthetic system and rubisco, a key enzyme in the Calvin cycle, was significantly upregulated, indicating that the glucose metabolism and photosynthetic pathways of the symbiotic system were involved in resistance to Cd toxicity. This revealed the response mechanism of the fungus-algal symbiotic system in the process of Cd adsorption, and also provided reference value for industrial application in water treatment.

Identification and characterization of yak α-lactalbumin and ß-lactoglobulin.

α-Lactalbumin (α-LA) and ß-lactoglobulin (ß-LG) were isolated from yak milk and identified by mass spectrometry. The variant of α-LA (L8IIC8) in yak milk had 123 amino acids, and the sequence differed from α-LA from bovine milk. The amino acid at site 71 was Asn (N) in domestic yak milk, but Asp (D) in bovine and wild yak milk sequences. Yak ß-LG had 2 variants, ß-LG A (P02754) and ß-LG E (L8J1Z0). Both domestic yak and wild yak milk contained ß-LG E, but it was absent in bovine milk. The amino acid at site 158 of ß-Lg E was Gly (G) in yak but Glu (E) in bovine. The yak α-LA and ß-LG secondary structures were slightly different from those in bovine milk. The denaturation temperatures of yak α-LA and ß-LG were 52.1°C and 80.9°C, respectively. This study provides insights relevant to food functionality, food safety control, and the biological properties of yak milk products.

Elucidating the impacts of cobalt (II) ions on extracellular electron transfer and pollutant degradation by anodic biofilms in bioelectrochemical systems during industrial wastewater treatment.

Electrogenic biofilms in bioelectrochemical systems (BES) are critical in wastewater treatment. Industrial effluents often contain cobalt (Co2+); however, its impact on biofilms is unknown. This study investigated how increasing Co2+ concentrations (0-30 mg/L) affect BES biofilm community dynamics, extracellular polymeric substances, microbial metabolism, electron transfer gene expression, and electrochemical performance. The research revealed that as Co2+ concentrations increased, power generation progressively declined, from 345.43 ± 4.07 mW/m2 at 0 mg/L to 160.51 ± 0.86 mW/m2 at 30 mg/L Co2+. However, 5 mg/L Co2+ had less effect. The Co2+ removal efficiency in the reactors fed with 5 and 10 mg/L concentrations exceeded 99% and 94%, respectively. However, at 20 and 30 mg/L, the removal efficiency decreased substantially, likely because of reduced biofilm viability. FTIR indicated the participation of biofilm functional groups in Co2+ uptake. XPS revealed Co2+ presence in biofilms as CoO and Co(OH)2, indicating precipitation also aided removal. Cyclic voltammetry and electrochemical impedance spectroscopy tests revealed that 5 mg/L Co2+ had little impact on the electrocatalytic activity, while higher concentrations impaired it. Furthermore, at a concentration of 5 mg/L Co2+, there was an increase in the proportion of the genus Anaeromusa-Anaeroarcus, while the genus Geobacter declined at all tested Co2+ concentrations. Additionally, higher concentrations of Co2+ suppressed the expression of extracellular electron transfer genes but increased the expression of Co2+-resistance genes. Overall, this study establishes how Co2+ impacts electrogenic biofilm composition, function, and treatment efficacy, laying the groundwork for the optimized application of BES in remediating Co2+-contaminated wastewater.

[Cryoprotective effects of deicing micro/nanomaterials with different sizes and shapes on cells].

Extensive studies have been conducted on deicing nanomaterials to improve the cryoprotective effects on cells, tissues, and organs. The nanomaterials with different composition, sizes, and shapes can inhibit the formation and growth of ice crystals, thereby reducing the damage to the cryopreserved samples. In this study, the carbon composite particles (CCPs) with different sizes and shapes were prepared by the hydrothermal method. The results demonstrated that the cryoprotective effect of CCPs enhanced with the decrease in particle size. Compared with spherical CCPs, Janus nanoparticles and WSP nanoflower with special shapes demonstrated improved protective effects on cryopreserved cells. In addition, the combination of deicing micro/nanomaterials at appropriate concentrations with commercial cryoprotectants exerted improved cryoprotective effects on cells. The prepared deicing micro/nanomaterials can improve cell cryopreservation, demonstrating great application potential in biomedical research and cryopreservation.

Construction of hemp seed protein isolate-phosphatidylcholine stablized oleogel-in-water gel system and its effect on structural properties and oxidation stability.

Rice bran wax was added to hemp seed oil (HSO) to prepare oleogel, and hemp seed protein isolate (HPI)-phosphatidylcholine (PC) was used as the emulsifier to obtain an oleogel-in-water (Og/W) gel system. The effect of HPI concentration on the construction of gel system was studied. Microscopic observations found that the oil droplets were encapsulated by the emulsifier. X-ray diffraction and Fourier transform infrared spectroscopy analysis showed that the increase in HPI concentration promoted the interaction between PC and protein, but didn't affect the crystal structure of gel. Thermogravimetric analysis showed that when the HPI concentration was 8 %, the sample formed a dense gel network and had good thermal stability. At this time, the oil holding capacity of gel was 98.81 ± 0.08 %, and the gel hardness was 109.55 ± 1.74 g. After 30 days of storage, the retention rate of Δ9-THC reached 96.3 %, and the peroxide value was 4.98 mmol/kg.

Bioimmobilization and transformation of chromium and cadmium in the fungi-microalgae symbiotic system.

Microalgae and fungi in the fungi-microalgae symbiotic system(FMSS) can solve the problems of deep purification of heavy metals in wastewater and harvesting of microalgae cell by synergistic interaction. Therefore, it is of great significance to use the FMSS for remediation of heavy metal pollution. However, at present, the immobilization and transformation mechanism of heavy metals in the FMSS is not clear, which limits the development and industrial application of the FMSS with high adsorption performance, high selectivity, and high tolerance. In this study, the FMSS constructed using Aspergillus funigatus and Synechocystis sp. PCC6803, was used as the research object to explore heavy metal adsorption performance. Under optimal conditions, the adsorption efficiencies of Cd(II) and Cr(VI) were as high as 90.02% and 80.03%, respectively. The adsorption process was controlled by both internal and external diffusion. Extracellular absorption was dominant, and intracellular absorption was secondary. XRD, XPS, SEM-EDX and TEM-EDX results revealed that ionic crystals and precipitates (Cd(OH)2, CdCO3, calcium oxalate crystals, Cr(OH)3, Cr2O3, and CrCl3) were formed after adsorption. The adsorption of Cr(VI) involved the reduction of Cr(VI). Functional groups, such as amino, carboxyl, aldehyde, and ether groups, on the cell surface also interact with heavy metal ions. To summarize, by constructing the FMSS, optimizing the symbiosis conditions, exploring the adsorption and accumulation rules of Cd(II) and Cr(VI) inside and outside the cells in the system, and revealing the molecular response mechanism, we were able to establish a theoretical basis for further understanding the interaction between the FMSS and heavy metals.

Interfacial composition in infant formulas powder modulate lipid digestion in simulated in-vitro infant gastrointestinal digestion.

The interface structure and composition of fat globules are very important for the digestion and metabolism of fat and growth in infants. Interface composition of fat globules in infant formula (IF) supplemented with milk fat globule membranes (MFGM) and lecithin in different ways were analyzed and their effects on fat digestion properties were evaluated. The results showed that the distribution of phospholipids at the interface and structural of Concept IF1 and Concept IF2 that were more similar to those of human milk (HM) than that of conventionally processed IF3. Concept IF2 and IF3 supplemented with lecithin had larger initial particle size and more sphingomyelin (SM) (23.12 ± 0.26 %, 26.94 ± 0.34 %) than Concept IF1, and Concept IF2 had the smallest proportion of casein in the interfacial. Due to its interface composition, Concept IF2 had the highest degree of lipolysis (85.07 ± 0.76 %), the phospholipid ring structure can always be observed during gastric digestion, and a final fatty acid composition released that was more similar to HM. Concept IF1 and IF3 were different from HM and Concept IF2 in terms of structure and lipolysis rate, although superior to commercial IF4. These indicate that changes in the interfacial composition and structure of fat globules improve the digestive properties of fats in IF. Overall, the results reported herein are useful in designing new milk formulas that better simulate HM.

The influence of MPL addition on structure, interfacial compositions and physicochemical properties on infant formula fat globules.

The lack of milk fat globule membrane phospholipids (MPL) at the interface of infant formula fat globules has an impact on the stability of fat globules, compared to human milk. Therefore, infant formula powders with different MPL contents (0%, 10%, 20%, 40%, 80%, w/w of MPL/whey protein mixture) were prepared, and the effect of interfacial compositions on the stability of globules was investigated. With increasing MPL amount, the particle size distribution had two peaks and returned to a uniform state when 80% MPL was added. At this composition, the MPL at the oil-water interface formed a continuous thin layer. Moreover, the addition of MPL improved the electronegativity and the emulsion stability. In terms of the rheological properties, increasing the concentration of MPL improved the elastic properties of the emulsion and the physical stability of the fat globules, while reducing the aggregation and agglomeration between fat globules. However, the potential for oxidation increased. Based on these results, the interfacial properties and stability on infant formula fat globules was significantly influenced by the level of MPL, which should be considered in the design of infant milk powders.

Synergism and mutualistic interactions between microalgae and fungi in fungi-microalgae symbiotic system.

The method of collecting microalgae using fungal mycelium pellets has attracted widespread attention because of its high efficiency and simplicity. In this study, the interaction in FMSS was explored using Aspergillus fumigatus and Synechocystis sp. PCC6803. Under the conditions of 25-30 °C, pH of 5.0, 160 rpm, a light intensity of 1000 lx, light to darkness ratio of 6:18 h, and glucose concentration of 1.5 g/L, the FMSS had the highest biomass and recovery efficiency. SEM, TEM, and Zeta analysis showed that microalgae can be fixed on the surface of fungal mycelium pellets by the electrostatic attraction (amino, amide, phosphate, hydroxyl, and aldehyde groups) of EPS. The N cycling and CO2-O2 cycling promoted the synthesis of amino acids and provided a guarantee for gas exchange, and the intermediate metabolites (CO32- and HCO3-/H2CO3) satisfied the metabolic activities. The microalgae and fungi worked in coordination each other, which was the mutualistic symbiosis.

The chemical composition and nitrogen distribution of Chinese yak (Maiwa) milk.

The paper surveyed the chemical composition and nitrogen distribution of Maiwa yak milk, and compared the results with reference composition of cow milk. Compared to cow milk, yak milk was richer in protein (especially whey protein), essential amino acids, fat, lactose and minerals (except phosphorus). The contents of some nutrients (total protein, lactose, essential amino acids and casein) were higher in the warm season than in the cold season. Higher ratios of total essential amino acids/total amino acids (TEAA/TAA) and total essential amino acids/total non essential amino acids (TEAA/TNEAA) were found in the yak milk from the warm season. However its annual average ratio of EAA/TAA and that of EAA/NEAA were similar to those of cow milk. Yak milk was rich in calcium and iron (p < 0.05), and thus may serve as a nutritional ingredient with a potential application in industrial processing.

Carboxymethyl chitosan based redox-responsive micelle for near-infrared fluorescence image-guided photo-chemotherapy of liver cancer.

High-efficient vectors for the co-delivery of photosensitizers and chemotherapeutics were urgently needed for the combination therapy. In this work, a redox-responsive micelle (PCL-SS-CMC-GA) was prepared for the co-delivery of doxorubicin (DOX) and pheophorbide A (PHA). Poly-ε-caprolactone was linked to carboxymethyl chitosan through a disulfide bond, which was easily broken in the reductive solution to release the payloads. The charge conversion property and glycyrrhetinic acid (GA) targeting ligand of the micelles effectively extended the average residence time (up to 18 times) in circulation and improved their intracellular uptake by HepG2 cells. The micelles exhibited an enhanced tumor accumulation and near infrared (NIR) imaging performance. More interestingly, this nanoplatform could fully exert the synergistic effect of DOX and PHA to improve the inhibition efficiency (with an inhibitory rate of 80.5 %) in vivo. With impressive photo-chemo theranostic and NIR imaging capability, PCL-SS-CMC-GA@DOX/PHA showed great potential in image-guided treatment of liver cancer.

Biosorption behavior and mechanism of cadmium from aqueous solutions by Synechocystis sp. PCC6803.

Cyanobacteria are promising adsorbents that are widely used for heavy metal removal in aqueous solutions. However, the underlying adsorption mechanism of Synechocystis sp. PCC6803 is currently unclear. In this study, the adsorption behavior and mechanism of cadmium (Cd2+) were investigated. Batch biosorption experiments showed that the optimal adsorption conditions were pH 7.0, 30 °C, 15 min, and an initial ion concentration of 4.0 mg L-1. The adsorption process fitted well with the pseudo-second order kinetic model, mainly based on chemisorption. Complexation of Cd2+ with carboxyl, hydroxyl, carbonyl, and amido groups was demonstrated by Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectrometry (EDX) analyses confirmed the presence of Cd2+ on the cyanobacterial cell surface and intracellularly. Cd2+ could lead to reactive oxygen species (ROS) accumulation and photosynthesis inhibition in cyanobacterial cells, and glutathione (GSH) played an important role in alleviating Cd2+ toxicity. Analyses of three-dimensional fluorescence spectroscopy (3D-EEM) and high performance anion exchange chromatography-pulsed amperometric detection (HPAEC-PAD) revealed the changes of the composition and content of EPS after Cd2+ adsorption, respectively. Real-time quantitative polymerase chain reaction (RT-qPCR) revealed the potential molecular regulatory mechanisms involved in Cd2+ biosorption. These results revealed the adsorption mechanism of Cd2+ by Synechocystis sp. PCC6803 and provided theoretical guidance for insight into the biosorption mechanisms of heavy metals by other strains.

Chitosan capped pH-responsive hollow mesoporous silica nanoparticles for targeted chemo-photo combination therapy.

Combination therapy provides an efficient way to overcome the potential multidrug resistance and enhance anticancer efficacy. In this work, a biodegradable pH-responsive hollow mesoporous silica nanoparticle (HMSN-GM-CS-FA) was developed for co-delivery of pheophorbide a (PA) and doxorubicin (DOX). This drug delivery system possessed controlled particle size and larger inner hollow core, which endowed the nanoparticle with excellent encapsulation capacities. The uptake efficiency of drug loaded nanoparticles HMSNs-GM-CS-FA@DOX/PA in cancer cells was greatly improved by folic acid-mediated endocytosis. The nanocarrier showed excellent drug controlled release properties based on the pH-dependent swelling effect of the coating layer. More importantly, the nanoplatform could fully combine photothermal-, photodynamic- and chemotherapies to develop synergistic antitumor efficacy. This strategy of integrating multi-therapeutic functions in one single formulation promised a powerful route to construct intelligent co-delivery carriers for efficient combinational clinical application.

Influence of interfacial adsorption of glyceryl monostearate and proteins on fat crystallization behavior and stability of whipped-frozen emulsions.

The effect of interfacial competitive adsorption of glyceryl monostearate (GMS) with proteins and GMS-fat (anhydrous milk fat; coconut oil) interactions on the fat crystallization behavior and stability of whipped-frozen emulsions were investigated. The results indicated GMS retarded the nucleation of emulsified anhydrous milk fat, but accelerated crystal growth. A contrasting outcome was elicited by emulsified coconut oil. Increasing GMS concentration strengthened and weakened the structural networking within anhydrous milk fat and coconut oil emulsions, respectively, which was evidenced by the oscillatory rheology results. Anhydrous milk fat whipped-frozen emulsions were characterized by increased partial coalescence degree with increasing GMS concentration. However, lower partial destabilization index and insignificant effect of GMS was found in coconut oil systems. Confocal laser scanning micrographs revealed that big clumps of fat globules were present at air bubble surfaces in anhydrous milk fat whipped-frozen emulsions, while only some individual fat globules were observed in coconut oil systems.

Chitosan based pH-responsive polymeric prodrug vector for enhanced tumor targeted co-delivery of doxorubicin and siRNA.

The co-delivery of chemotherapeutic drugs and siRNA has gained increasing attentions owing to the enhanced antitumor efficacy over single administration. In this work, a chitosan-based pH-responsive prodrug vector was developed for the co-delivery of doxorubicin (DOX) and Bcl-2 siRNA. The accumulation of fabricated nanoparticles in hepatoma cells was enhanced by glycyrrhetinic acid receptor-mediated endocytosis. The cumulative release amount of the encapsulated DOX and siRNA reached 90.2 % and 81.3 % in 10 h, respectively. More strikingly, this nanoplatform can efficiently integrate gene- and chemo-therapies with a dramatically enhanced tumor inhibitory rate (88.0 %) in vivo. This co-delivery system may provide the latest strategy to meet the needs of combination therapies for tumors, offering safe and efficient improvements to the synergistic antitumor efficacy of gene-chemotherapies.

pH-Sensitive mesoporous silica nanoparticles for chemo-photodynamic combination therapy.

In order to optimize the chemotherapeutic efficacy of doxorubicin (DOX) and improve the photodynamic therapeutic effectiveness of rose bengal (RB), a mesoporous silica nanoparticle system was designed as the carrier of RB and DOX for chemo-photodynamic combination therapy. A pH-sensitive strategy has been exploited to enhance the delivery efficiency. Our results suggested that the production of singlet oxygen was independent of the release of RB while strongly influenced by the external DOX layer. This method showed several benefits, including accelerating cellular uptake of the payloads and enabling chemo-photodynamic combination therapy for synergistic cancer treatment. Our study provides a new way for co-delivery of chemotherapy agents and photosensitizers.

Acid-sensitive polymeric vector targeting to hepatocarcinoma cells via glycyrrhetinic acid receptor-mediated endocytosis.

Liver cancer is one of the top death causing cancers, traditional treatments have not settled for the requirement of patients. In this work, a smart acid-responsive micelle based on glycyrrhetinic acid modified chitosan-polyethyleneimine-4-Hydrazinobenzoic acid-doxorubicin (GA-CS-PEI-HBA-DOX) was synthesized for targeted delivery of DOX to liver cancer. A dual pH-sensitive and receptor-mediated strategy has been exploited to enhance the delivery efficiency. The micelle possesses positive charges under pH 6.8 and can be turned into negative charges above pH 7.0, which help to be accumulated in tumor tissues (pH 6.0-7.0). In the intracellular environment (pH 4.5-6.5) of tumor cells, the pH-sensitive hydrazone bonds between DOX and GA-CS-PEI-HBA would break and release as much as 90.3% of the encapsulated payloads in 48 h. In addition, GA was modified to improve the targeting abilities. The micelles exhibited high lethality to HepG2 cells while showed much lower cytotoxicity to HUVEC cells. With high drug-loading capacity and the targeted release ability, the GA-CS-PEI-HBA-DOX micelle might be employed as a promising candidate for targeted cancer treatment.

Effective co-delivery of doxorubicin and curcumin using a glycyrrhetinic acid-modified chitosan-cystamine-poly(ε-caprolactone) copolymer micelle for combination cancer chemotherapy.

A glycyrrhetinic acid-modified chitosan-cystamine-poly(ε-caprolactone) copolymer (PCL-SS-CTS-GA) micelle was developed for the co-delivery of doxorubicin (DOX) and curcumin (CCM) to hepatoma cells. Glycyrrhetinic acid (GA) was used as a targeting unit to ensure specific delivery. Co-encapsulation of DOX and CCM was facilitated by the incorporation of poly(ε-caprolactone) (PCL) groups. The highest drug loading content was 19.8% and 8.9% (w/w) for DOX and CCM, respectively. The PCL-SS-CTS-GA micelle presented a spherical or ellipsoidal geometry with a mean diameter of approximately 110nm. The surface charge of the micelle changed from negative to positive, when the pH value of the solution decreased from 7.4 to 6.8. Meanwhile, it also exhibited a character of redox-responsive drug release and GA/pH-mediated endocytosis in vitro. In simulated body fluid with 10mM glutathione, the release rate in 12h was 80.6% and 67.2% for DOX and CCM, respectively. The cell uptake of micelles was significantly higher at pH 6.8 than pH 7.4. The combined administration of DOX and CCM was facilitated by PCL-SS-CTS-GA micelle. Results showed that there was strong synergic effect between the two drugs. The PCL-SS-CTS-GA micelle might turn into a promising and effective carrier for improved combination chemotherapy.