Naturally biocompatible melanin based iron-complex nanoparticles for pH-responsive magnetic resonance imaging.

The sensitivity and diagnostic accuracy of magnetic resonance imaging mainly depend on the relaxation capacity of contrast agents (CAs) and their accumulated amount at the pathological region. Due to the better biocompatibility and high-spin capacity, Fe-complexes have been studied widely as an alternative to replace popular Gd-based CAs associated with potential biotoxicity. Compared with a variety of Fe complex-based CAs, such as small molecular, macrocyclic, multinuclear complexes, the form of nanoparticle exhibits outstanding longitudinal relaxation, but the clinical transformation was still limited by the inconspicuous difference of contrast between tumor and normal tissue. The enhanced effect of contrast is a positive relation as relaxation of CAs and their concentration in desired region. To specifically improve the amount of CAs accumulated in the tumor, pH-responsive polymer poly(2-ethyl-2-oxazoline) (PEOz) was modified on melanin, a ubiquitous natural pigment providing much active sites for chelating with Fe(III). The Fe(III)-Mel-PEOz we prepared could raise the tumor cell endocytosis efficiency via switching surface charge from anion to cation with the stimuli of the decreasing pH of tumor microenvironment. The change of pH has negligible effect on ther1of Fe(III)-Mel-PEOz, which is always maintained at around 1.0 mM-1s-1at 0.5 T. Moreover, Fe(III)-Mel-PEOz exhibited low cytotoxicity, and satisfactory enhancement of positive contrast effectin vivo. The excellent biocompatibility and stable relaxation demonstrate the high potential of Fe(III)-Mel-PEOz in the diagnosis of tumor.

A responsive nanoplatform with molecular and structural imaging capacity for assisting accurate diagnosis of early rheumatoid arthritis.

Accurate early diagnosis of rheumatoid arthritis (RA) and prompt implementation of appropriate treatment approaches are crucial. In the clinic, magnetic resonance imaging (MRI) has been recommended for implementation to aid in the precise and early diagnosis of RA. However, they are still limited by issues regarding specificity and their ability to capture comprehensive information about the pathological features. Herein, a responsive multifunctional nanoplatform with targeting capabilities (hMnO2-IR@BSA-PEG-FA) is constructed through integrating a RA microenvironment-responsive MRI contrast agent with activatable near-infrared (NIR) fluorescence imaging, aiming to simultaneously acquire comprehensive pathological features of RA from both structural and molecular imaging perspectives. Moreover, taking advantage of its targeting function to synovial microphages, hMnO2-IR@BSA-PEG-FA demonstrated a remarkable capability to accumulate effectively at the synovial tissue. Additionally, hMnO2 responded to the mild acidity and reactive oxygen species (ROS) in the RA microenvironment, leading to the controlled release of Mn2+ ions and IR780, which separately caused special MRI contrast enhancement of synovial tissues and sensitively demonstrated the presence of ROS and weakly acid microenvironment by NIR imaging. Consequently, hMnO2-IR@BSA-PEG-FA is expected to serve as a promising nanoplatform, offering valuable assistance in the precise diagnosis of early-stage RA by specially providing comprehensive information about the pathological features.

Protective Effect of Egg Yolk Lipids against Dextran Sulfate Sodium-Induced Colitis: The Key Role of Gut Microbiota and Short-Chain Fatty Acids.

Egg yolk lipids significantly alleviate dextran sulfate sodium (DSS)-induced colitis by inhibiting NLRP3 inflammasome, reversing gut microbiota dysbiosis, and increasing short chain fatty acids (SCFAs) concentrations. However, the role of gut microbiota and the relationship between SCFAs and NLRP3 inflammasome are still unknown. Here, this study confirms that antibiotic treatment abolishes the protective effect of egg yolk lipids on DSS-induced colonic inflammation, intestinal barrier damage, and lipopolysaccharide translocation. Fecal microbiota transplantation also supports that egg yolk lipids alleviate colitis in a gut microbiota-dependent manner. Then, the study investigates the relationship between SCFAs and NLRP3 inflammasome, and finds that SCFAs significantly suppress colitis via inhibiting colonic NLRP3 inflammasome activation and proinflammatory cytokines secretions (interleukin, IL)-1ß and IL-18, and combined treatment of SCFAs and MCC950 (NLRP3 inhibitor) shows a better activity against colitis and NLRP3 inflammasome activation. Together, these findings provide positive evidence for gut microbiorta-SCFAs-NLRP3 axis as a novel target involving in the therapy of inflammatory bowel disease.

Exciton Dynamics of TiOPc/WSe2 Heterostructure.

The van der Waals (vdW) heterostructures composed of two-dimensional (2D) transition metal dichalcogenides (TMDs) and organic semiconductors demonstrate numerous compelling optoelectronic properties. However, the influence of the vdW epitaxial effect and temperature on the optoelectronic properties and interface exciton dynamics of heterostructures remains unclear. This study systematically investigates the fluorescence properties of TiOPc/WSe2 heterostructure. Comprehensive spectral characterization elucidates that the emission behavior of the TiOPc/WSe2 heterostructure arises from charge/energy transfer at the heterostructure interfaces and the structural ordering of the organic layer on the 2D monolayer WSe2 induced by vdW epitaxy. The interface exciton dynamic features probed by ultrafast transient spectroscopy reveal that the face-to-face molecular stacking configuration of TiOPc exhibits ultrafast exciton dynamics. In particular, we observe picosecond-scale absorption of organic molecular dimer cations, providing direct evidence of interface charge transfer at room temperature. Moreover, energy transfer from the TiOPc to WSe2 may exist based on the tunability in the fluorescence emission of the TiOPc/WSe2 heterostructure as the temperature changes. This study unveils the critical role of vdW epitaxy and temperature in the exciton dynamics of organic/2D TMDs hybrid systems and provides guidance for studying interlayer charge and energy transfer in organic/inorganic heterostructures.

A high-performance broadband phototransistor array of a PdSe2/SOI Schottky junction.

There is great interest in the incorporation of novel two-dimensional materials into Si-based technologies to realize multifunctional optoelectronic devices via heterogeneous integration. Here, we demonstrate a gate-tunable, self-driven, high-performance broadband phototransistor array based on a PdSe2/Si Schottky junction, which is fabricated by pre-depositing a semi-metallic PdSe2 film on a SOI substrate. In addition, thanks to the zero bandgap of the PdSe2 material and the PdSe2/Si vertical heterostructure, the prepared phototransistor exhibits pronounced photovoltaic properties in a wide spectral range from ultraviolet to near-infrared. The responsivity, specific detectivity and response time of the device at the incident light wavelength of 808 nm are 1.15 A W-1, 9.39 × 1010 Jones, and 27.1/40.3 µs, respectively, which are better than those of previously reported PdSe2-based photodetectors. The photoelectric performance can be further improved by applying an appropriate gate voltage to the phototransistor and the responsivity of the device increases to 1.61 A W-1 at VG = 5 V. We demonstrate the excellent imaging capabilities of a 4 × 4 array image sensor using PdSe2/SOI phototransistors under 375 nm, 532 nm, and 808 nm laser sources.

Mechanism of ultrasonic enhancement of the gelling properties of salted ovalbumin-cooked soybean isolate hybrid gels.

The influence of ultrasonic processing on the physicochemical characteristics, microstructure, and intermolecular forces of the hybrid gels obtained by heating the mixtures of different ratios of salted ovalbumin (SOVA)-cooked soybean protein isolate (CSPI) was investigated. With the growth of SOVA addition, ζ-potential in absolute value, cohesiveness, water-holding capacity (WHC), surface hydrophobicity, and the content of soluble protein of the hybrid gels decreased (P < 0.05), while the hardness, T2 relaxation time of the hybrid gels increased (P < 0.05). And the compactness of the network structure of the hybrid gel increased with the increase of SOVA addition. After being treated with ultrasound, significant increases (P < 0.05) of ζ-potential in absolute value, cohesiveness, WHC, and surface hydrophobicity of the hybrid gels were observed. In general, ultrasonic processing is one of the effective means to improve the gel properties of SOVA-CSPI hybrid gels.

Egg Yolk Lipids Alleviated Dextran Sulfate Sodium-Induced Colitis by Inhibiting NLRP3 Inflammasome and Regulating Gut Microbiota.

The increasing incidence of inflammatory bowel disease (IBD) has become a global phenomenon. Egg yolk lipids are one of the essential dietary foods, but its effects on intestinal immunity remain unclear. Here, egg yolk lipids are obtained using ethanol extraction and a total of 601 kinds of lipids are detected via lipidomics, including 251 kinds of triglycerides, 133 kinds of phosphatidylcholines, 44 kinds of phosphatidylethanolamines. Then, the study finds that egg yolk lipids significantly alleviate dextran sulfate sodium-induced colitis and reduce the production of inflammatory factors. Meanwhile, egg yolk lipids also maintain intestinal barrier integrity and decrease lipopolysaccharide translocation by alleviating intestinal structure damage and increasing the numbers of goblet cells and mucin 2. Mechanistically, egg yolk lipids attenuate colitis by inhibiting the assembly and activation of NLRP3 inflammasome. Moreover, the study also finds that egg yolk lipids reverse gut microbiota dysbiosis referring to increased relative abundance of Bacteroides acidifaciens and decrease relative abundance of Akkermansia muciniphila, as well as increased short chain fatty acids concentration in the gut. Together, the study elucidates the anti-colitis effect of egg yolk lipids and provides positive evidences for egg yolk lipids involving in dietary strategy and IBD therapy.

Egg yolk phosphatidylcholine alleviates DSS-induced colitis in BALB/c mice.

Ulcerative colitis (UC) is a common inflammatory bowel disease, whose incidence is on the rise worldwide. The drugs commonly used for UC are often associated with a number of side effects. Therefore, the development of effective, food-borne substances for UC is in line with the current needs. Egg yolk phosphatidylcholine (EYPC) is one of the abundant lipids in egg yolk and possesses various biological activities. However, its protective effect against UC has not been clarified. In this study, the anti-UC activity of EYPC was investigated using a dextran sodium sulfate (DSS)-induced colitis model of BALB/c mice. The results showed that EYPC supplementation inhibited DSS-induced colon shortening, the spleen index and disease activity index increase and intestinal structural damage. EYPC could down-regulate the levels of TNF-α, IL-1ß, IL-6 and MPO in the colon and restore the number of goblet cells and the level of tight junction (TJ) proteins. Besides, EYPC modulated the composition of the gut microbiota, lowered the relative abundance of the pathogenic bacterium Parabacteroides and upregulated the abundance of the beneficial bacteria Alistipes and Lachnospiraceae_NK4A136_group. These results evidenced that EYPC could attenuate DSS-induced colitis in mice and had the potential to prevent and treat UC.

An Amorphous Native Oxide Shell for High Bias-Stress Stability Nanowire Synaptic Transistor.

The inhomogeneous native oxide shells on the surfaces of III-V group semiconductors typically yield inferior and unstable electrical properties metrics, challenging the development of next-generation integrated circuits. Herein, the native GaOx shells are profitably utilized by a simple in-situ thermal annealing process to achieve high-performance GaSb nanowires (NWs) field-effect-transistors (FETs) with excellent bias-stress stability and synaptic behaviors. By an optimal annealing time of 5 min, the as-constructed GaSb NW FET demonstrates excellent stability with a minimal shift of transfer curve (ΔVth ≈ 0.54 V) under a 60 min gate bias, which is far more stable than that of pristine GaSb NW FET (ΔVth ≈ 8.2 V). When the high bias-stress stability NW FET is used as the chargeable-dielectric free synaptic transistor, the typical synaptic behaviors, such as short-term plasticity, long-term plasticity, spike-time-dependent plasticity, and reliable learning stability are demonstrated successfully through the voltage tests. The mobile oxygen ion in the native GaOx shell strongly offsets the trapping states and leads to enhanced bias-stress stability and charge retention capability for synaptic behaviors. This work provides a new way of utilizing the native oxide shell to realize stable FET for chargeable-dielectric free neuromorphic computing systems.

Thickness effect of 2D PdSe2film on performance of PdSe2/Si heterostructure photodetectors.

Two-dimensional (2D) PdSe2film has the characteristics of adjustable bandgap, high carrier mobility, and high stability. Photodetector (PD) based on 2D PdSe2exhibits wide spectral self-driving features, demonstrating enormous potential in the field of optical detection. Here, we design and fabricate PdSe2/Si heterojunction PDs with various thicknesses of the PdSe2films from 10 to 35 nm. Due to the enhancement of light absorption capacity and built-in electric field of heterojunction, the photodetector with thicker PdSe2film can generate more photo-generated carriers and effectively separate them to form a large photocurrent, thus showing more excellent photodetection performance. The responsivity and specific detectivity of the PdSe2/Si PDs with 10 nm, 20 nm, and 35 nm PdSe2films are 2.12 A W-1and 6.72 × 109Jones, 6.17 A W-1and 1.95 × 1010Jones, and 8.02 A W-1and 2.54 × 1010Jones, respectively (808 nm illumination). The PD with 35 nm PdSe2film exhibits better performance than the other two PDs, with the rise/fall times of 15.8µs/138.9µs atf= 1 kHz and the cut-off frequency of 8.6 kHz. Furthermore, we demonstrate that the properties of PdSe2/Si PD array have excellent uniformity and stability at room temperature and shows potential for image sensing in the UV-vis-NIR wavelength range.

Photoelectric characteristics of hydrogen-terminated polycrystalline diamond MESFETs.

In the field of diamond MESFETs, this work is what we believe to be the first to investigate the optoelectronic properties of hydrogen-terminated polycrystalline diamond MESFETs under visible and near-UV light irradiation. It is shown that the diamond MESFETs are well suited for weak light detection in the near-ultraviolet region around the wavelength of 368 nm, with a responsivity of 6.14 × 106 A/W and an external quantum efficiency of 2.1 × 107 when the incident light power at 368.7 nm is only 0.75 µW/cm2. For incident light at 275.1 nm, the device's sensitivity and EQE increase as the incident light power increases; at an incident light power of 175.32 µW/cm2 and a VGS of -1 V, the device's sensitivity is 2.9 × 105 A/W and the EQE is 1.3 × 106. For incident light in the wavelength range of 660 nm to 404 nm with an optical power of 70 µW/cm2, the device achieves an average responsivity of 1.21 × 105 A/W. This indicates that hydrogen-terminated polycrystalline diamond MESFETs are suitable for visible and near-UV light detection, especially for weak near-UV light detection. However, the transient response test of the device shows a long relaxation time of about 0.2 s, so it is not yet suitable for high-speed UV communication or detection.

Ovotransferrin Inhibits TNF-α Induced Inflammatory Response in Gastric Epithelial Cells via MAPK and NF-κB Pathway.

Ovotransferrin (OVT) has been confirmed to have anti-inflammatory activity. However, its effect and mechanism on gastric inflammation are unclear. In this study, the effect and mechanism of the OVT on the tumor necrosis factor-α (TNF-α) induced inflammatory response in gastric epithelial cells (GES-1) were investigated. The enzyme linked immunosorbent assay (ELISA) was used to determine the levels of inflammation cytokines, followed by RNA sequencing to explore the potential pathways of its anti-inflammatory effect, and then it was validated by Western blotting and pathways inhibitors. Results showed that the OVT at concentrations of 50-400 µg/mL displayed nontoxicity against GES-1 cells. Additionally, 100 µg/mL of OVT obviously reduced the secretion of interleukin (IL)-8, IL-6, and TNF-α by 63.02% (630.09/1703.98), 35.53% (935.81/1451.43), and 36.19% (964.60/1511.63), respectively. The results of RNA sequencing exhibited that the OVT significantly influences the activation of mitogen-activated protein kinase (MAPK) and the nuclear factor kappa-light-chain enhancer of activated B cell (NF-κB) pathways, which was verified by the levels of p-IKK, p-IκB, p-P65, p-ERK, p-JNK, and p-P38 protein. IL-8 contents released by GES-1 cells after incubation with inhibitors of NF-κB and MAPK pathways further confirmed that OVT hindered activation of these two pathways. Collectively, these results suggested that OVT was a natural protein with the potential to treat gastric inflammation.

Hypoxia-Responsive T2-to-T1 Dynamically Switchable Extremely Small Iron Oxide Nanoparticles for Sensitive Tumor Imaging In Vivo.

To realize the accurate diagnosis of tumors by magnetic resonance imaging (MRI), switchable magnetic resonance contrast agents (CAs) between T1 and T2 contrast enhancement that are constructed based on extremely small iron oxide nanoparticles (ESIONPs) have been developed in recent years. We herein report, for the first time, a novel ESIONP-based nanocluster (named EAmP), which exhibited hypoxia responsiveness to the tumor microenvironment and offered a T2-to-T1-switchable contrast enhancement function, effectively distinguishing between the normal tissue and tumor tissue. In detail, active perfluorophenyl ester-modified ESIONPs with a diameter of approximately 3.6 nm were initially synthesized, and then 4,4'-azodianiline was used as a cross-linker to facilitate the formation of nanoclusters from ESIONPs through the reaction between the active ester and amine. Finally, poly(ethylene glycol) was further modified onto nanoclusters by utilizing the remaining active ester residues. The resulting EAmP demonstrated satisfactory colloidal stability and favorable biosafety and exhibited a desired T2-to-T1-switchable function, as evidenced by conversion from nanocluster to the dispersed state and a significant decrease in the r2/r1 ratio from 14.86 to 1.61 when exposed to a mimical hypoxic environment in the solution. Moreover, EAmP could decompose into dispersed ESIONPs at the tumor region, resulting in a switch from T2 to T1 contrast enhancement. This T2-to-T1-switchable contrast agent offers high sensitivity and signal-to-noise ratio to realize the accurate diagnosis of tumors. In conclusion, hypoxia-responsive EAmP is a potential MRI nanoprobe for improving the diagnostic accuracy of solid tumors.

A tumor-targeting and ROS-responsive iron-based T1 magnetic resonance imaging contrast agent for highly specific tumor imaging.

T1 contrast agents (CAs) exhibit outstanding capacity in enhancing the magnetic resonance imaging (MRI) contrast between tumor tissues and normal tissues for generating bright images. However, the clinical application of representative gadolinium(III) chelate-based T1 CAs is limited due to their potential toxicity and low specificity for pathological tissues. To obtain MRI CAs with a combination of low toxicity and high tumor specificity, herein, we report a reactive oxygen species (ROS)-responsive T1 CA (GA-Fe(II)-PEG-FA), which was constructed by chelating Fe(II) with gallic acid (GA), and modified with tumor-targeted folic acid (FA). The resultant CA could accumulate in tumor tissues via the affinity between FA and their receptors on the tumor cell membrane. It realized the switch from Fe(II) to Fe(III), and further enhancing the longitudinal relaxation rate (r1) under the stimuli of ROS in the tumor microenvironment. The r1 of GA-Fe(II)-PEG-FA on a 0.5 T nuclear magnetic resonance analyzer increased to 2.20 mM-1 s-1 under ROS stimuli and was 5 times greater than the r1 (0.42 mM-1 s-1) before oxidation. The cell and in vivo experiments demonstrated that GA-Fe(II)-PEG-FA exhibited good biocompatibility and significant targeting specificity to tumor cells and tumor tissues. Furthermore, in vivo MRI studies demonstrated that the enhanced T1 contrast effect against tumors could be achieved after injecting the CA for 3 h, indicating that GA-Fe(II)-PEG-FA has the potential as an ideal tumor MRI CA to increase the contrast and improve the diagnostic precision.

High-Performance Diamond Phototransistor with Gate Controllable Gain and Speed.

This paper presents a fabricated solar-blind phototransistor based on hydrogen-terminated diamond. The phototransistor shows a large photocurrent and enhancement of responsivity over conventional two-terminal diamond-based photodetector. These enhancement effects are owing to the internal gain of the phototransistor. The fabricated phototransistor exhibits a high photoresponsivity (R) of 2.16 × 104 A/W and a detectivity (D*) of 9.63 × 1011 jones, with gate voltage (VG) and drain voltage of approximately -1.5 V and -5 V, respectively, under 213 nm light illumination. Even at ultralow operating voltage of -0.01 V, the device records satisfactory performance with R and D* of 146.7 A/W and 6.19 × 1010 jones, respectively. By adjusting the VG, photocurrent generation in the device can be continuously tuned from the fast photoconductive effect to the optical gating effect with high optical gain. When VG increases from 1.4 to 2.4 V, the decay time decreases from 1512.0 to 25.5 ms. Therefore, responsivity, dark current, Iphoto/Idark, and decay time of the device can be well tuned by VG.

Industrial Application of Protein Hydrolysates in Food.

Protein hydrolysates, which may be produced by the protein in the middle of the process or added as an ingredient, are part of the food formula. In food, protein hydrolysates are found in many forms, which can regulate the texture and functionality of food, including emulsifying properties, foaming properties, and gelation. Therefore, the relationship between the physicochemical and structural characteristics of protein hydrolysates and their functional characteristics is of significant importance. In recent years, researchers have conducted many studies on the role of protein hydrolysates in food processing. This Review explains the relationship between the structure and function of protein hydrolysates, and their interaction with the main ingredients of food, to provide reference for their development and further research.

A review on the development of pickled eggs: rapid pickling and quality optimization.

Pickled eggs enjoy a long processing history with unique flavor and rich nutrition but suffer from long pickling cycle due to the limitations of traditional processing methods. In terms of quality, salted egg whites have the disadvantage of high sodium content, and salted egg yolks have problems such as hard core and black circle around outer layer. Likewise, the quality of preserved eggs is challenged by the black spots (dots) on the eggshells and the high content of heavy metals in the egg contents. The sustainable development of traditional pickled eggs are hindered by these defects and extensive research has been carried out in recent years. Based on the elaboration of the quality formation mechanism of salted eggs and preserved eggs, this paper reviewed the processing principles and applications of rapid pickling technologies like ultrasonic technology, magnetoelectric-assisted technology, water cycle technology, vacuum decompression technology, and pulsed pressure technology, as well as the quality optimization methods such as controlling the sodium content of the salted egg whites, improving the quality of salted egg yolks, promoting the quality of lead-free preserved eggs, and developing heavy metal-free preserved eggs. In the end, the future development trend of traditional pickled eggs was summarized and prospected in order to provide theoretical guidance for the actual production.

Ovotransferrin alleviated acute gastric mucosal injury in BALB/c mice caused by ethanol.

Acute gastric mucosal injury is a common gastrointestinal disorder, which influences patients' life quality. It was found that ovotransferrin (OVT) reduces the abundance of Helicobacter pylori associated with gastric disease in the intestine of immunosuppressed mice. To clarify its gastric protective function, the present study investigated the effect of OVT on BALB/c mice with ethanol-induced gastric mucosal injury. Results showed that OVT attenuated the ethanol-induced gastric mucosal injury. Furthermore, OVT effectively downregulated the expression of inflammatory markers (tumor necrosis factor-α, interleukin (IL)-1ß and IL-6) but enhanced the secretion of IL-4, IL-10 and prostaglandin E2. And OVT pretreatment significantly inhibited the activation of the MAPK/NF-κB pathway. Additionally, OVT improved gastric antioxidant ability by increasing superoxide dismutase and glutathione levels and decreasing malondialdehyde and myeloperoxidase content. Pretreatment with OVT modulated the equilibrium between B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X. The above results indicated that OVT alleviated inflammatory responses, oxidative stress and apoptosis in gastric mucosal injury mice caused by ethanol.

Effects of citric acid crosslinking on the structure and properties of ovotransferrin and chitosan composite films.

In this study, ovotransferrin/chitosan (OVT/CS) composite films cross-linked by citric acid (CA) were prepared and the effects of CA cross-linking on the structure and physicochemical properties of the composite films were investigated. The cross-linking degree measured by 2,4,6-trinitrobenzenesulfonic acid (TNBS) method confirmed that CA was cross-linked with the matrix, and Fourier transform infrared spectroscopy confirmed that more hydrogen bonds and electrostatic interactions were formed between CA and the matrix. Differential scanning calorimetry, X-ray diffraction and Scanning electron microscope images revealed the compatibility between substances. The synergistic inhibition between the matrix results in a significantly higher antibacterial activity of the composite film than the pure film. Compared with uncross-linked films, the mechanical properties, barrier properties and water resistance of the cross-linked films were significantly improved. When the concentration of CA was 5 wt% (W/W, on a dry basis of the weight of OVT and CS), the most significant improvement in film performance was obtained. The tensile strength of the film increased from 32.05 MPa without cross-linking to 61.99 MPa and the swelling degree decreased from 51.5 % to 24.23 %. The observed phenomena suggest that cross-linking OVT and CS with CA can obtain functional edible films with improved properties.

Effects of different copper salts on the physicochemical properties, microstructure and intermolecular interactions of preserved egg white.

This study was conducted to investigate the effects of different copper salts on the physicochemical properties, microstructure and intermolecular interactions of preserved egg white (PEW) during pickling. With increased pickling time, the alkalinity of the pickling solution and the moisture of PEW pickled by three copper salts (CuSO4, CuCl2 and Cu(CH3COO)2) gradually decreased, while the pH showed dynamic trends. During the early stage of pickling, the viscosity of PEW changed dynamically. With the progress of pickling, the hardness and springiness of PEW increased gradually and the α-helix structure gradually transformed into a more stable ß-structure. The main forces that maintained PEW gel were ionic and disulfide bonds. In the early stage of pickling, the alkali penetration rate of CuCl2 pickled preserved eggs was faster, and better gel strength and network structure were observed, followed by CuSO4 and Cu(CH3COO)2, while there were no significant differences in the later stage of pickling.