Three-dimensional Gel Research Articles

25 放射線治療のための3次元ゲル線量計の開発と臨床応用

25 放射線治療のための3次元ゲル線量計の開発と臨床応用

SDH6 and SDH7 Contribute to Anchoring Succinate Dehydrogenase to the Inner Mitochondrial Membrane in Arabidopsis thaliana.

The succinate dehydrogenase complex (complex II) is a highly conserved protein complex composed of the SDH1 to SDH4 subunits in bacteria and in the mitochondria of animals and fungi. The reason for the occurrence of up to four additional subunits in complex II of plants, termed SDH5 to SDH8, so far is a mystery. Here, we present a biochemical approach to investigate the internal subunit arrangement of Arabidopsis (Arabidopsis thaliana) complex II. Using low-concentration detergent treatments, the holo complex is dissected into subcomplexes that are analyzed by a three-dimensional gel electrophoresis system. Protein identifications by mass spectrometry revealed that the largest subcomplex (IIa) represents the succinate dehydrogenase domain composed of SDH1 and SDH2. Another subcomplex (IIb) is composed of the SDH3, SDH4, SDH6, and SDH7 subunits. All four proteins include transmembrane helices and together form the membrane anchor of complex II. Sequence analysis revealed that SDH3 and SDH4 lack helices conserved in other organisms. Using homology modeling and phylogenetic analyses, we present evidence that SDH6 and SDH7 substitute missing sequence stretches of SDH3 and SDH4 in plants. Together with SDH5, which is liberated upon dissection of complex II into subcomplexes, SDH6 and SDH7 also add some hydrophilic mass to plant complex II, which possibly inserts further functions into this smallest protein complex of the oxidative phosphorylation system (which is not so small in plants).

3D dosimetric validation of motion compensation concepts in radiotherapy using an anthropomorphic dynamic lung phantom

In this study, we developed a new setup for the validation of clinical workflows in adaptive radiation therapy, which combines a dynamic ex vivo porcine lung phantom and three-dimensional (3D) polymer gel dosimetry. The phantom consists of an artificial PMMA-thorax and contains a post mortem explanted porcine lung to which arbitrary breathing patterns can be applied. A lung tumor was simulated using the PAGAT (polyacrylamide gelatin gel fabricated at atmospheric conditions) dosimetry gel, which was evaluated in three dimensions by magnetic resonance imaging (MRI). To avoid bias by reaction with oxygen and other materials, the gel was collocated inside a BAREX™ container. For calibration purposes, the same containers with eight gel samples were irradiated with doses from 0 to 7 Gy. To test the technical feasibility of the system, a small spherical dose distribution located completely within the gel volume was planned. Dose delivery was performed under static and dynamic conditions of the phantom with and without motion compensation by beam gating. To verify clinical target definition and motion compensation concepts, the entire gel volume was homogeneously irradiated applying adequate margins in case of the static phantom and an additional internal target volume in case of dynamically operated phantom without and with gated beam delivery. MR-evaluation of the gel samples and comparison of the resulting 3D dose distribution with the planned dose distribution revealed a good agreement for the static phantom. In case of the dynamically operated phantom without motion compensation, agreement was very poor while additional application of motion compensation techniques restored the good agreement between measured and planned dose. From these experiments it was concluded that the set up with the dynamic and anthropomorphic lung phantom together with 3D-gel dosimetry provides a valuable and versatile tool for geometrical and dosimetrical validation of motion compensated treatment concepts in adaptive radiotherapy.

Study on the synergistic effect of clinoptilolite on the swelling kinetic and slow release behavior of maize bran-based superabsorbent nanocomposite

A new type of maize bran (MB)-based superabsorbent nanocomposite with fertilizer slow-release property was synthesized by free-radical graft copolymerization of acrylic acid (AA) and acrylamide (AAm) monomers onto MB backbone in the presence of clinoptilolite (clino) and NPK fertilizer compound. The FTIR results indicated that the grafting reaction and the nanocomposite formation have been performed, successfully. Rheological analyses were done to evaluate the stability of the three-dimensional cross-linked gel network of synthesized hydrogels. The effect of variable factors such as salt solution type and concentration, and solution pH on the water absorbency of hydrogel samples was investigated. Also, swelling kinetic studies for all hydrogel samples were performed. Rheological measurements revealed that all hydrogel samples had a strong gel framework with stable crosslinked network. Moreover, superabsorbent nanocomposite showed higher gel strength compared with neat hydrogel which was due to the additional physical crosslinking effect of clino particles. The equilibrium water absorption capacity of the synthesized hydrogels in all saline solutions was lower than that of values in distilled water. Additionally, hydrogel samples showed pH-sensitive swelling behavior. Fertilizer release studies showed that NPK loaded superabsorbent nanocomposite possesses excellent slow-release behavior. Besides, it had better water retention capacity in soil. These results revealed that the superabsorbent nanocomposite with good slow-release and water retention properties, being cost effective and environment-friendly can efficiently improve the utilization of fertilizer and water resources in agricultural and horticultural applications.

Filling perovskite (5-AVA)y(CH3NH3)1−yPbI3 or (5-AVA)y(CH3NH3)1−yPbI3−xClx halide in a 3D gel framework for multi-deformable perovskite solar cell

Application-specific requirements for future perovskite solar cells include lightweight, mechanical resilience, and deformability for multi-purpose utilizations ranging from electronic skin and implant in the body to wearable textiles. Here we demonstrate the experimental realization of intrinsically bendable, stretchable, twistable, and compressible perovskite solar cells made by adsorbing hole-transporting polyaniline, solvothermal-processed halide (5-AVA)y(CH3NH3)1−yPbI3 or (5-AVA)y(CH3NH3)1−yPbI3−xClx precursor as well as electron-transporting [6,6]-phenyl-C61-butyric acid methyl with three-dimensional amphiphilic gel matrix. The multi-deformable perovskite solar cell with CH3NH3PbI3 crystals yields a power conversion efficiency of 3.62% at undeformed state and AM1.5G sunlight irradiation, while the efficiency can increase to 4.51% at a bending angle of 140°, to 4.46% at an elongation of 220%, to 5.10% at a twist angle of 360°, and to 5.57% at a compression ratio of 80%. After hundreds of arbitrary deformations, the solar cell still remains ~130% efficiency. Owing to an amphiphilic surface, the solar cell is relatively stable for 7 days when exposed in 78%-humidity ambient air. This work represents a significant step forward, as it realizes the solvothermal synthesis of halide CH3NH3PbX3 (X=I, Cl) precursors and low-temperature fabrication, arbitrary deformations without sacrificing power conversion efficiency along with promising humidity-resistance in ambient atmosphere for perovskite solar cells.

Effect of pullulan on gel properties of Scomberomorus niphonius surimi

Pullulan possesses uniquely good structural flexibility and solubility. Surimi is an aquatic product prepared from minced fish flesh, which is washed to remove most lipids, blood, enzymes and sarcoplasmic proteins. However, data on effect of pullulan on gel properties of fish surimi are limited. This study investigated the influence of pullulan at different concentrations (0–2g/100 g wet materials) on the properties of Scomberomorus niphonius surimi gel including the water holding capacity, adhesiveness, cohesiveness and microstructure. The addition of pullulan increased the water holding capacity, adhesiveness and cohesiveness and formed a more stable and ordered three-dimensional gel complex. Therefore, the addition of pullulan increased the gel properties of S. niphonius surimi gel.

Fabrication of stable galactosylated alginate microcapsules via covalent coupling onto hydroxyl groups for hepatocytes applications

Galactose moieties are covalently coupled with sodium alginate to enhance liver-specific functions in microcapsules owing to the specific interaction between the galactose moieties and the asialoglycoprotein receptors (ASGPRs) of hepatocytes. In this study, galactosylated alginate (L-NH2-OH-alginate) based microcapsules with desirable stability and a suitable 3D microenvironment are designed and fabricated for primary hepatocyte applications. The designed L-NH2-OH-alginate is fabricated via the application of ethylenediamine grafted lactobionic acid (L-NH2) onto the hydroxyl groups of sodium alginate so that the negatively charged carboxyl groups intact in L-NH2-OH-alginate can effectively bond with Ca2+ to form a stable three-dimensional gel network; a subsequent reaction with polycations forms a stable membrane of microcapsules. As a result, L-NH2-OH-alginate based microcapsules exhibit an excellent mechanical stability. Moreover, with a higher degree of substitution in L-NH2-OH-alginate (DS 0.41), the hepatocytes entrapped in L-NH2-OH-alginate microcapsules exhibit better viability and well-maintained liver-specific functions.

Chondrocyte Morphology in Stiff and Soft Agarose Gels and the Influence of Fetal Calf Serum.

Changes to chondrocyte volume/morphology may have deleterious effects on extracellular matrix (ECM) metabolism potentially leading to cartilage deterioration and osteoarthritis (OA). The factors controlling chondrocyte properties are poorly understood, however, pericellular matrix (PCM) weakening may be involved. We have studied the density, volume, morphology, and clustering of cultured bovine articular chondrocytes within stiff (2% w/v) and soft (0.2% w/v) three-dimensional agarose gels. Gels with encapsulated chondrocytes were cultured in Dulbecco's Modified Eagle's Medium (DMEM; fetal calf serum (FCS) 1-10%;380 mOsm) for up to 7 days. Chondrocytes were fluorescently labeled after 1, 3, and 7 days with 5-chloromethylfluorescein-diacetate (CMFDA) and propidium iodide (PI) or 1,5-bis{[2-(di-methylamino)ethyl]amino}-4,8-dihydroxyanthracene-9,10-dione (DRAQ5) to identify cytoplasmic space or DNA and imaged by confocal laser scanning microscopy (CLSM). Chondrocyte density, volume, morphology, and clustering were quantified using Volocity™ software. In stiff gels after 7 d with 10% FCS, chondrocyte density remained unaffected and morphology was relatively normal with occasional cytoplasmic processes. However, in soft gels by day 1, chondrocyte volume increased (P = 0.0058) and by day 7, density increased (P = 0.0080), along with the percentage of chondrocytes of abnormal morphology (P < 0.0001) and enhanced clustering (P < 0.05), compared to stiff gels. FCS exacerbated changes to density (P < 0.01), abnormal morphology (P < 0.001) and clustering (P < 0.01) compared to lower concentrations at the same gel strength. Reduced gel stiffness and/or increased FCS concentrations promoted chondrocyte proliferation and clustering, increased cell volume, and stimulated abnormal morphology, producing similar changes to those occurring in OA. The increased penetration of factors in FCS into soft gels may be important in the development of these abnormal chondrocyte properties. J. Cell. Physiol. 232: 1041-1052, 2017. © 2016 Wiley Periodicals, Inc.

Removal of Humic Acid from Water Using Pt/biochar Electrode Reactor

A Pt/biochar electrode reactor was developed to remove humic acid in water. The removal efficiency and characteristics of the reactor were investigated. Experimental results showed that Pt/biochar electrode reactor obtained 74.58% removal rate after 300 min reaction under current density of 20 mA·cm-2. The removal rate was increased by 58.3% comparing with 47.10% removal rate achieved by Pt/graphite electrode reactor. Electrochemical oxidation and air floating played the main roles in removal of humic acid from water. The improved removal efficiency of humic acid in Pt/biochar electrode reactor was attributed to the fact that the biochar cathode could produce more H2O2 than graphite cathode. Three-dimensional excitation emission matrix fluorescence spectroscopy and Gel permeation chromatography measurement revealed that Pt/biochar electrode reactor had strong oxidation capability to mineralize the low molecular weight humic acid directly. It suggests that biochar could be use as an innovative cathode material of electrode reactor for organic pollutants treatment in water.

Fluorescence imaging of reactive oxygen species byconfocal laser scanning microscopy for track analysis of synchrotron X-ray photoelectric nanoradiatordose: X-ray pump-optical probe.

Bursts of emissions of low-energy electrons, including interatomic Coulomb decay electrons and Auger electrons (0-1000 eV), as well as X-ray fluorescence produced by irradiation of large-Z element nanoparticles by either X-ray photons or high-energy ion beams, is referred to as the nanoradiator effect. In therapeutic applications, this effect can damage pathological tissues that selectively take up the nanoparticles. Herein, a new nanoradiator dosimetry method is presented that uses probes for reactive oxygen species (ROS) incorporated into three-dimensional gels, on which macrophages containing iron oxide nanoparticles (IONs) are attached. This method, together with site-specific irradiation of the intracellular nanoparticles from a microbeam of polychromatic synchrotron X-rays (5-14 keV), measures the range and distribution of OH radicals produced by X-ray emission or superoxide anions ({\rm{O}}_2^-) produced by low-energy electrons. The measurements are based on confocal laser scanning of the fluorescence of the hydroxyl radical probe 2-[6-(4'-amino)phenoxy-3H-xanthen-3-on-9-yl] benzoic acid (APF) or the superoxide probe hydroethidine-dihydroethidium (DHE) that was oxidized by each ROS, enabling tracking of the radiation dose emitted by the nanoradiator. In the range 70 µm below the irradiated cell, ^\bullet{\rm{OH}} radicals derived mostly from either incident X-ray or X-ray fluorescence of ION nanoradiators are distributed along the line of depth direction in ROS gel. In contrast, {\rm{O}}_2^- derived from secondary electron or low-energy electron emission by ION nanoradiators are scattered over the ROS gel. ROS fluorescence due to the ION nanoradiators was observed continuously to a depth of 1.5 mm for both oxidized APF and oxidized DHE with relatively large intensity compared with the fluorescence caused by the ROS produced solely by incident primary X-rays, which was limited to a depth of 600 µm, suggesting dose enhancement as well as more penetration by nanoradiators. In conclusion, the combined use of a synchrotron X-ray microbeam-irradiated three-dimensional ROS gel and confocal laser scanning fluorescence microscopy provides a simple dosimetry method for track analysis of X-ray photoelectric nanoradiator radiation, suggesting extensive cellular damage with dose-enhancement beyond a single cell containing IONs.

Contribution of Fiber Undulation to Mechanics of Three‐Dimensional Collagen‐I Gel

SummaryThe collagen‐I gel is extensively used as a scaffold material in tissue engineering due to its ability to mimic the extracellular matrix (ECM). In this study, the mechanics of collagen‐I gel is investigated using a numerical model of three‐dimensional collagen network. The resulted mechanical behavior was validated against the published experimental data. Results illustrated that fiber alignment was dominated in the low strain region, and its transition to stretching dominated phenomena at higher strain led to the strain stiffening of collagen gel. The collagen undulation at the microscopic level was found to delay the initiation of strain stiffening.

Size-resolved morphological properties of the high Arctic summer aerosol during ASCOS-2008

Abstract. The representation of aerosol properties and processes in climate models is fraught with large uncertainties. Especially at high northern latitudes a strong underprediction of aerosol concentrations and nucleation events is observed and can only be constrained by in situ observations based on the analysis of individual aerosol particles. To further reduce the uncertainties surrounding aerosol properties and their potential role as cloud condensation nuclei this study provides observational data resolved over size on morphological and chemical properties of aerosol particles collected in the summer high Arctic, north of 80° N. Aerosol particles were imaged with scanning and transmission electron microscopy and further evaluated with digital image analysis. In total, 3909 aerosol particles were imaged and categorized according to morphological similarities into three gross morphological groups: single particles, gel particles, and halo particles. Single particles were observed between 15 and 800 nm in diameter and represent the dominating type of particles (82 %). The majority of particles appeared to be marine gels with a broad Aitken mode peaking at 70 nm and accompanied by a minor fraction of ammonium (bi)sulfate with a maximum at 170 nm in number concentration. Gel particles (11 % of all particles) were observed between 45 and 800 nm with a maximum at 154 nm in diameter. Imaging with transmission electron microscopy allowed further morphological discrimination of gel particles in "aggregate" particles, "aggregate with film" particles, and "mucus-like" particles. Halo particles were observed above 75 nm and appeared to be ammonium (bi)sulfate (59 % of halo particles), gel matter (19 %), or decomposed gel matter (22 %), which were internally mixed with sulfuric acid, methane sulfonic acid, or ammonium (bi)sulfate with a maximum at 161 nm in diameter. Elemental dispersive X-ray spectroscopy analysis of individual particles revealed a prevalence of the monovalent ions Na+/K+ for single particles and aggregate particles and of the divalent ions Ca2+/Mg2+ for aggregate with film particles and mucus-like particles. According to these results and other model studies, we propose a relationship between the availability of Na+/K+ and Ca2+/Mg2+ and the length of the biopolymer molecules participating in the formation of the three-dimensional gel networks.

A photoresponsive azobenzene-bridged cubic silsesquioxane network

An azobenzene (AZO)-bridged cubic silsesquioxane network exhibiting reversible photoisomerization behavior in nonpolar solvents has been prepared via hydrosilylation reaction between 4,4′-diallyloxy-azobenzene and octahydridosilsesquioxane (H8Si8O12; H-POSS). Approximately 70 % of the corner Si–H groups of H-POSS are reacted to form a three-dimensional gel network while maintaining the cubic siloxane structure. The dried gel has a high thermal stability, which is attributed to the highly cross-linked cubic silsesquioxane network where AZOs are covalently incorporated in the main chain. The gel exhibits reversible swelling behavior in nonpolar solvents during wetting–drying cycles. In toluene, a large extent of reversible trans–cis isomerization of the AZO moiety is observed. These results are promising for the design of a new class of photoresponsive materials applicable in host–guest chemistry.

Formation mechanism of ovalbumin gel induced by alkali

In this paper, the alkali-induced gelling behavior of ovalbumin, including its microstructure characteristics, intermolecular forces, and molecular structure changes, was investigated. The results showed that ovalbumin formed a three-dimensional gel with an ordered fibrous mesh structure under alkali conditions. The active force between gel molecules was maintained by a large number of ionic bonds (∼85%), a small number of disulfide bonds (∼5%), and very few hydrophobic interactions and hydrogen bonds. SDS-PAGE analysis showed that ovalbumin formed aggregates via ionic and disulfide bonds. ANS fluorescence spectroscopy analysis showed that strong alkali caused rapid denaturation of ovalbumin molecules to expose the hydrophobic core, thus greatly increasing the surface hydrophobicity. However, the hydrophobicity decreased during the gelation stage. FTIR analysis showed that strong alkali induced the secondary-level structure of ovalbumin molecules to interconvert, and most of them existed in a relatively stable α-folding structure. Endogenous fluorescence and UV spectroscopic analyses showed that the amino acid residues of ovalbumin in the gelation stage moved towards the polar environment. It was concluded that the secondary and tertiary structures of ovalbumin changed after treatment with strong alkali and that a crystal gel formed through the action of ionic and disulfide bonds. In addition, the long-term action of strong alkali gradually decreased the gelatinous property.

Three-dimensional model of biomatrix as a method of studying blood vessels and nerve growth in tissue engineering structures

The method involves isolating and culturing ex vivo cultures of mouse dorsal root ganglia and abdominal aorta in a three-dimensional gel (Matrigel). Unlike other explant cultures, this technique allows to study the physiological and biochemical processes in the tissue explants of dorsal root ganglia and abdominal aorta in three-dimensional space but in contrast to a two-dimensional adhesive culture. Administration of the tested substances to the Matrigel allows analyzing their effects on the growth of blood vessels and neurites from the explants for 21 days. The developed method can be applied in modern cardiological and neurobiological research and explores how new therapeutic agents can accelerate the regeneration of blood vessels and nerves.

Effect of Worm Predation on Changes in Waste Activated Sludge Properties.

This study explored the effects of worm predation on changes in waste activated sludge properties. Results showed that the rate by which worm predation reduced mixed liquor volatile suspended solids (MLVSS) was approximately 23.7% ± 3.1%. Particle size distribution and extracellular polymeric substance (EPS) analyses indicated that the reduction of fine particles and EPS content in sludge predated by worms mainly increased dewaterability and reduced the ratio of MLVSS/mixed liquor suspended solids. Moreover, both mean particle size and protein/carbohydrate ratio increased. The results of three-dimensional excitation-emission matrix and gel filtration chromatogram analyses demonstrated the varied properties of soluble microbial products and EPS were attributed to the worms' selective predation of low molecular-weight organic matter, which facilitated the hydrolysis of macromolecular organic matter.

Evaluation of cell and matrix mechanics using fluorescence excitation spectroscopy: Feasibility study in collagen gels containing fibroblasts.

Collagen gels containing cells are commonly used in tissue engineering, wound healing, and cancer research to investigate the interplay between cells and the extracellular matrix (ECM), as changes in the density and stiffness of the microenvironment are known to play a role in many diseases or pathological conditions. In these gels, the stiffness is regularly determined using destructive methods, such as indentation and tensile tests. Certain molecules native to cells and the ECM display fluorescence upon irradiation with ultraviolet light. The objective of the present study was to investigate the feasibility of using the endogenous, or innate, fluorescence of collagen gels containing fibroblasts as an optical marker to evaluate changes in the mechanical properties of the ECM. Human foreskin fibroblasts cells at concentrations of 50,000 and 100,000 cells/ml were cultured in three-dimensional gels of type I collagen for 16 days. Fibroblast cells remodeled the ECM, contracting and increasing the stiffness of the gel. During this remodeling process, changes in mechanical properties and fluorescence were measured with an indentation test and a spectrofluorometer, respectively. Force and displacement measurements from the indentation test were used to calculate the elastic modulus of the gel. Maps of fluorescence intensity, at excitation/emission of 240-520/290-530 nm, were used to identify the wavelengths of interest. Fluorescence excitation/emission maps exhibited two distinct excitation/emission bands whose intensities increased as the fibroblasts remodeled and increased the stiffness of the ECM: The 290/340 nm band ascribed to tryptophan and the 330/390 nm band ascribed to cross-links of collagen (pepsin-digestible cross-links). A Spearman correlation analysis, between the elastic modulus of the gel containing fibroblasts and the fluorescence of cross-links of collagen, resulted in R = 0.95 (P < 0.05) and R = 0.77 (P = 0.12) for 50,000 and 100,000 cells/ml, respectively. The endogenous fluorescence intensity ascribed to pepsin-digestible cross-links of collagen may serve as an optical marker to evaluate changes in the mechanical properties of the ECM; this is relevant to collagenous tissues for which pathological states are related to mechanical alterations, such as keratoconus in cornea and osteoarthritis in articular cartilage.

Characterization of mesenchymal stem cells and fibrochondrocytes in three-dimensional co-culture: analysis of cell shape, matrix production, and mechanical performance.

BackgroundBone marrow mesenchymal stem cells (MSCs) have shown positive therapeutic effects for meniscus regeneration and repair. Preliminary in vitro work has indicated positive results for MSC applications for meniscus tissue engineering; however, more information is needed on how to direct MSC behavior. The objective of this study was to examine the effect of MSC co-culture with primary meniscal fibrochondrocytes (FCCs) in a three-dimensional collagen scaffold in fibrochondrogenic media. Co-culture of MSCs and FCCs was hypothesized to facilitate the transition of MSCs to a FCC cell phenotype as measured by matrix secretion and morphology.MethodsMSCs and FCCs were isolated from bovine bone marrow and meniscus, respectively. Cells were seeded in a 20 mg/mL high-density type I collagen gel at MSC:FCC ratios of 0:100, 25:75, 50:50, 75:25, and 100:0. Constructs were cultured for up to 2 weeks and then analyzed for cell morphology, glycosaminoglycan content, collagen content, and production of collagen type I, II, and X.ResultsCells were homogeneously mixed throughout the scaffold and cells had limited direct cell–cell contact. After 2 weeks in culture, MSCs transitioned from a spindle-like morphology toward a rounded phenotype, while FCCs remained rounded throughout culture. Although MSC shape changed with culture, the overall size was significantly larger than FCCs throughout culture. While 75:25 and 100:0 (MSC mono-culture) culture groups produced significantly more glycosaminoglycan (GAG)/DNA than FCCs in mono-culture, GAG retention was highest in 50:50 co-cultures. Similarly, the aggregate modulus was highest in 100:0 and 50:50 co-cultures. All samples contained both collagen types I and II after 2 weeks, and collagen type X expression was evident only in MSC mono-culture gels.ConclusionsMSCs shift to a FCC morphology in both mono- and co-culture. Co-culture reduced hypertrophy by MSCs, indicated by collagen type X. This study shows that MSC phenotype can be influenced by indirect homogeneous cell culture in a three-dimensional gel, demonstrating the applicability of MSCs in meniscus tissue engineering applications.Electronic supplementary materialThe online version of this article (doi:10.1186/s13287-016-0301-8) contains supplementary material, which is available to authorized users.

Changes of microstructure characteristics and intermolecular interactions of preserved egg white gel during pickling

Changes in gel microstructure characteristics and in intermolecular interactions of preserved egg whites during pickling were investigated. Spin–spin relaxation times of preserved egg whites significantly decreased in the first 8days and remained unchanged after the 16th day. SEM images revealed a three-dimensional gel network, interwoven with a loose linear fibrous mesh structure. The protein gel mesh structure became more regular, smaller, and compacted with pickling time. Free sulfhydryl contents in the egg whites increased significantly, while total sulfhydryl contents dramatically decreased during pickling. The primary intermolecular forces in the preserved egg white gels were ionic and disulfide bonds. Secondary forces included hydrophobic interaction and relatively few hydrogen bonds. During the first 8days, the proportion of ionic bonds sharply decreased, and that of disulfide bonds increased over the first 24days.

Morphology transformation between nanofibres and vesicles controlled by ultrasound and heat in tryptamine-based assembly

A novel low-molecular-mass organic gelator T1 containing tryptamine and sugar segments was designed and synthesised which can gelate alcohols accelerated by heat and sonication. Interestingly, morphology exchange between vesicles as precipitate and a three-dimensional gel network tuned by heating and ultrasound was observed. The mechanism was studied by IR, FL, X-ray diffraction. It was presented that the effect of ultrasound was to disturb the spontaneous self-assembly of T1 molecule, and promote the long arrangement and disordered assembly of T1 molecules into fibrous networks, thus resulting in the gelation in methanol.