Search Results (1,216)

Background/Objectives: The synthesis of protein nanoparticles (NPs) using the coacervation method is influenced by critical parameters. The use of glutaraldehyde limits the pharmacological applications of NPs in humans due to the potential toxicity of residual aldehydes that remain after the purification of the nanoparticles. The aim was to assess heat effect as a crosslinking agent for the synthesis of bovine serum albumin (BSA)–capsaicin nanoparticles and its effect on the physicochemical characteristics of nanoparticles. Results: The initial concentrations of BSA and capsaicin in the formulation were directly correlated with the amount of BSA that was transformed into nanoparticles and the loaded capsaicin (r = 0.97, p = 0.0003 and r = 0.95, p = 0.0003), respectively. Furthermore, the morphometric parameters of nanoparticles were affected by the increase in capsaicin concentration, but not by temperature. The nanoparticles increased in dimensions and showed a loss of shape due to coalescence between nanoparticles. The ζ-potential decreased with the increase in the concentration of capsaicin added. This effect compromised the stability of the nanoparticles; on the other hand, molecular interactions were observed between hydrophobic residues of phenylalanine and tyrosine in BSA and the hydrophobic moiety of capsaicin. At the same time, BSA nanoparticles showed a potential for disassembling and delivering the payload capsaicin, which caused an antisteatotic effect in the liver of a murine model. Conclusions: heat (70 °C) can replace crosslinking agents, such as glutaraldehyde. This property is particularly useful when an aldehyde-free synthesis of BSA nanoparticles is needed. Full article

In this study, the insufficient ability of tartary buckwheat protein (TBP) to stabilize Pickering emulsions was addressed by preparing TBP–sodium alginate (SA) composite particles via cross-linking and systematic optimization of the preparation parameters. The results showed that at a pH of 9.0 with 1.0% (w/v) TBP and 0.2% (w/v) SA, the zeta potential of the prepared TBP–SA composite particles was significantly more negative, and the particle size was significantly larger, than those of TBP, while emulsifying activity index and emulsifying stability index increased to 53.76 m²/g and 78.78%, respectively. Scanning electron microscopy confirmed the formation of a dense network structure; differential scanning calorimetry revealed a thermal denaturation temperature of 83 °C. Fourier transform infrared spectroscopy and surface hydrophobicity results indicated that the complex was formed primarily through hydrogen bonding and hydrophobic interactions between TBP and SA, which induced conformational changes in the protein. The Pickering emulsion prepared with 5% (w/v) TBP–SA composite particles and 60% (φ) oil phase was stable during 4-month storage, at a high temperature of 75 °C, high salt conditions of 600 mM, and pH of 3.0–9.0. The stabilization mechanisms may involve: (1) strong electrostatic repulsion provided by the highly negative zeta potential; (2) steric hindrance and mechanical strength imparted by the dense interfacial network; and (3) restriction of droplet mobility due to SA-induced gelation. Full article

Elastin is the principal protein found in the elastic fibers of vertebrate tissues, and the water within these fibers plays a crucial role in preserving the structure and function of this hydrophobic protein. Soluble elastin was successfully obtained by repeatedly treating insoluble elastin, extracted from pig aorta, with oxalic acid. Solid-state NMR analysis was performed on the soluble elastin, focusing on conformation-dependent chemical shifts of alanine residues. This analysis revealed that cross-linked alanine residues exhibited both α-helix and random coil structures in the dry state. In contrast, the hydrated state favored random coil structures, with some distorted helices possibly present, indicating that the cross-linked configuration is relatively unstable. Similar conformational changes were observed in insoluble elastin, mirroring those found in the soluble form. Additionally, when the soluble elastin was re-cross-linked using 1,12-dodecanedicarboxylic acid and 4-hydroxyphenyl dimethylsulfonium methylsulfate, it retained a mixture of α-helix and random coil structures in the dry state. Remarkably, in the hydrated state, α-helix structures were more prominently preserved alongside random coils. These structural changes corresponded with increased stiffness of molecular chains in the hydrophobic regions compared to their state prior to re-cross-linking, even under hydrated conditions. Full article

Hydrogels with protein–polysaccharide combinations are widely used in the field of tissue engineering, as they can mimic the in vivo environments of native tissues, specifically the extracellular matrix (ECM). However, achieving stability and mechanical properties comparable to those of tissues by employing natural polymers remains a challenge due to their weak structural characteristics. In this work, we optimized the fabrication strategy of a hydrogel composite, comprising gelatin and sodium alginate (Gel-SA), by varying reaction parameters. Magnetite (Fe₃O₄) nanoparticles were incorporated to enhance the mechanical stability and structural integrity of the scaffold. The changes in hydrogel stiffness and viscoelastic properties due to variations in polymer mixing ratio, crosslinking time, and heating cycle, both before and after nanoparticle incorporation, were compared. FTIR spectra of crosslinked hydrogels confirmed physical interactions of Gel-SA, metal coordination bonds of alginate with Ca²⁺, and magnetite nanoparticles. Tensile and rheology tests confirmed that even at low magnetite concentration, the Gel-SA-Fe₃O₄ hydrogel exhibits mechanical properties comparable to soft tissues. This work has demonstrated enhanced resilience of magnetite-incorporated Gel-SA hydrogels during the heating cycle, compared to Gel-SA gel, as thermal stability is a significant concern for hydrogels containing gelatin. The interactions of thermoreversible gelatin, anionic alginate, and nanoparticles result in dynamic hydrogels, facilitating their use as viscoelastic acellular matrices. Full article

Polyphenol oxidases (PPOs) are enzymes that oxidize mono- and diphenolic compounds to o-quinones, facilitating pigment formation and protein crosslinking in food systems, thereby improving their techno-functional properties. However, most PPOs function optimally near neutral pH, limiting their application in acidic food products. This study aimed to extract acid-adapted PPOs from various fruit by-products, including Hass avocado seeds (pH 5.9), Anjou pears (pH 4.0), Bartlett pears (pH 4.0), Red Delicious apples (pH 4.0), and McIntosh apples (pH 3.3), and characterize PPO properties and its substrate specificity using colorimetric assay. SDS-PAGE was used to assess PPOs’ molecular weight and PPOs’ capacity for plant protein crosslinking. The results showed that PPOs from Anjou and Bartlett pear pomace exhibited the most robust acid-adapted activity, with effective catalytic performance in the pH ranges of 4.0–5.0 and 5.0–8.0, respectively, and an optimal temperature of 20 °C. SDS-PAGE analysis revealed bands at ~44 kDa and ~25.6 kDa, consistent with previously found pear PPO isoforms. Both pear pomace PPO oxidized L-DOPA and EGCG efficiently, but showed minimal activity toward L-tyrosine, gallic acid, caffeic acid, tannic acid, and ferulic acid. In the presence of EGCG, both pear pomace PPOs are capable of crosslinking plant proteins at pH 4.0. These findings provide the first evidence that agricultural by-products are a promising but underutilized source of acid-adapted PPO for modifying soy protein hydrolysates. Full article

The keratin-associated proteins (KAPs) are a class of wool proteins. They form a matrix that cross-links the wool intermediate filament keratins. The KAPs are thought to affect wool fibre structure and properties and have been associated with variation in wool fibre traits. There are many KAP genes in sheep, but not all have been identified. Recently a second member of the KAP22 gene family, KRTAP22-2, was identified in goats, and variation in this caprine gene was associated with cashmere fibre traits. In this study, we identified ovine KRTAP22-2. To ascertain the extent of variation in KRTAP22-2, sheep from eight breeds were investigated using polymerase chain reaction (PCR) followed by single-strand conformational polymorphism (SSCP) analysis. This revealed two unique banding patterns, which upon sequencing gave two novel DNA sequences. These differed by two single nucleotide polymorphisms in the coding region. Three genotypes of the novel KRTAP22-2 sequences were observed in the eight sheep breeds studied. The ovine KRTAP22-2 variant sequences were similar to a goat KRTAP22-2 variant, but a search of ovine expressed sequence tags revealed no matching mRNA sequences in the ovine databases. In a second part of the study, no association was found between the KRTAP22-2 genotypes and mean fibre diameter, fibre diameter standard deviation, coefficient of variation in fibre diameter, and mean fibre curvature, for either the fine wool or heterotypic hair fibres of 255 Chinese Tan lambs. These results suggests that sheep have a KRTAP22-2 gene, but that there may be species-specific differences in the gene’s expression or function. The gene may not affect wool traits in the way that it appears to in goats. Full article

Background/Objectives: Corneal re-epithelialization is a critical process following surgical procedures such as photorefractive keratectomy (PRK), phototherapeutic keratectomy (PTK), and corneal UV cross-linking (CXL), as well as cases of corneal abrasion. Delayed epithelial healing can lead to increased discomfort, a higher risk of infection, and suboptimal visual outcomes. This retrospective case series aims to evaluate the efficacy of a novel ophthalmic solution containing cross-linked carboxymethyl cellulose (CX-CMC) and silk proteins in promoting corneal re-epithelialization and improving post-surgical recovery. Patients and methods: A total of 15 patients who underwent PRK, PTK, or CXL or who presented with corneal abrasions were included in the study. Along with standard post-surgical treatment, patients received CX-CMC and silk protein-based eye drops (CORDEV, Ophtagon, Rome, Italy) six times a day. Corneal epithelial thickness was assessed using topography at follow-up visits. Results: Corneal re-epithelialization was observed in all subjects within 24 to 48 h post-procedure. The mean corneal epithelial thickness at 48 h was 73.21 µm, which falls within the typical range of a proliferating corneal epithelium. Conclusions: The CX-CMC and silk protein-based formulation accelerated corneal healing, achieving rapid epithelial recovery. This novel ophthalmic solution offers a promising alternative to conventional post-surgical treatments, potentially improving patient outcomes by reducing healing time, minimising discomfort, and lowering the risk of complications associated with delayed re-epithelialization. Full article

In this study, the heat treatment of white kidney beans was optimized by a single-factor experiment and an orthogonal experiment. Taking in vitro digestibility as an index, the optimum technological parameters for heating white kidney beans were determined as follows: water addition of 225%, medium pressure heating for 30 min, and a temperature of 110 °C. The results of scanning electron microscopy showed that the layered structure in white kidney beans disappeared, and the original particle morphology was lost. The protein network was broken, forming an irregular agglomerate or flocculent structure, and the porous structure formed by heat-induced crosslinking effectively delayed the contact of amylase. Heat-treated white kidney beans were added to rice, and their nutritional components were determined, and the glycemic index was estimated in vitro to determine the best addition amount. The results of the in vitro digestion rate showed that the rice treated with 40% white kidney beans significantly reduced the glycemic index (eGI = 41.48), and the texture analysis showed that the viscoelasticity of rice could be improved by compounding 40% white kidney beans. It also effectively improves the taste of 100% white rice. This study can provide interdisciplinary solutions for the development of staple food for diabetes and provide a scientific basis for the development of staple food with a low glycemic index and the improvement of traditional diets. Full article

Fish skin gelatin (FG) has garnered considerable attention as a potential substitute for mammalian gelatin. In this study, Takifugu rubripes skin gelatin was chemically modified using transglutaminase (TG) and epigallocatechin gallate (EGCG). Subsequently, the rheological, structural, and physicochemical properties of FG modified with varying concentrations of TG and EGCG were systematically examined and compared. As the concentrations of TG and EGCG increased, more extensive interactions occurred in FG, leading to a significant enhancement of gelatin properties. Following modification, the molecular weight of FG proteins increased, and this was accompanied by enhanced surface hydrophobicity and gel strength. Rheological analysis further demonstrated that the viscosity of FG modified with TG and EGCG was higher than that of unmodified FG and was positively correlated with the treatment concentrations of TG and EGCG. Additionally, the results indicated that the effect of TG modification was more pronounced than that of EGCG modification. Overall, this study demonstrates that both TG and EGCG modifications can effectively overcome the inherent limitations of fish skin gelatin, with TG showing superior efficiency as a cross-linking agent. The enhanced thermal stability, gel strength, and rheological properties achieved through these interactions significantly expand the potential applications of fish gelatin in the food industry, making it a more viable alternative to mammalian gelatin. Full article

Approximately half of the world population is infected with the human pathogen Helicobacter pylori, which causes gastric inflammation, chronic gastritis, or peptide ulceration. A significant factor in the colonization of the upper digestive system is the helical shape of H. pylori. This helical form is maintained by a complex network of peptidoglycan (PG)-modifying enzymes and cytoskeletal proteins. Among these, the D,D-endopeptidase Csd2 plays a central role, working in conjunction with other cell shape-determining (Csd) proteins. Csd1 and Csd2 have been categorized as members of the M23B metallopeptidase family. These enzymes are classified as D,D-endopeptidases, and their function involves the cleavage of the D-Ala4-mDAP3 bond, which is present in the cross-linked di-mer muropeptides. Despite the fact that the structure of the Csd1:Csd2 complex has been examined via biochemical methods, information on the in vivo localization and dynamics of D,D-endopeptidases is still missing. Here, we use an approach that employs sophisticated different microscopy methods to visualize the spatial temporal localization and dynamics of Csd2, involving both structured illumination microscopy and single-molecule tracking. Our findings thus contribute to refining the existing model for this cellular complex by revealing curvature-dependent spatial organization and temporal dynamics underlying peptidoglycan remodeling processes essential for helical cell shape formation and maintenance. Understanding the dynamics provides insight into the mechanisms that maintain bacterial morphology and potential targets for therapeutic intervention. Full article

Plectin is a key cytolinker protein that functions as an integrator of the cytoskeletal networks by crosslinking intermediate filaments with actin filaments and microtubules. Mutations or function deficiencies of plectin lead to tissue disorders, particularly affecting the skin, muscle, and nervous tissues. Interestingly, plectin dysregulation in cancer, characterized by aberrant expression and mislocalization, has been increasingly observed, suggesting distinct roles in tumorigenesis and progression. Here, we focus on recent advances regarding the roles of plectin dysregulation in promoting cell proliferation, suppressing cell apoptosis, sustaining the stemness of cancer stem cells, and driving invasion and metastasis. We also discuss its bidirectional interplay with the tumor microenvironment, including modulating immune and inflammatory responses, promoting angiogenesis, sensing and transmitting mechanical cues from the extracellular matrix, and contributing to matrix remodeling. Finally, we highlight emerging therapeutic strategies that target plectin dysregulation with anticancer activity. By summarizing these advances, we aim to enhance the understanding of plectin dysregulation in cancer and illuminate its potential as a therapeutic target. Full article

Considering the high stability of water-in-oil (W/O) emulsions, contamination from emulsified pollutants poses a long-term risk to the environment. In this study, hybrid membranes composed of wheat gluten amyloid fibrils (WGAFs) and zein nanoparticles (ZNPs) were prepared and used as a separator to remove emulsified W/O droplets from the oily phase. ZNPs and WGAFs were synthesized through antisolvent method and fibrillation process. Next, a ZNP-functionalized wheat gluten AF/methyl cellulose (ZNP-WGAF/MC) hybrid membrane was fabricated, and its properties were investigated via various analytical techniques. Lastly, the separation efficiency of the ZNP-WGAF/MC hybrid membrane for various W/O emulsions was assessed using microscopy and light scattering. The formation of ZNPs or WGAFs was first verified via spectroscopic and microscopic methods. Our results indicated that the ZNP-WGAF/MC hybrid membranes were synthesized via chemical crosslinking coupled with the casting method. Furthermore, the incorporation of either WGAFs or ZNPs was found to improve the thermal stability and surface hydrophobicity of membranes. Finally, the separation efficiency of the ZNP-WGAF/MC hybrid membranes for various W/O emulsions was determined to be ~87–99%. This research demonstrates the potential of harnessing three-dimensional membranes composed of plant protein-based fibrils and nanoparticles to separate emulsified W/O mixtures. Full article

Background/Objectives: DNA-damaging agents can contribute to genetic instability, and such agents are often used in cancer chemotherapeutic regimens due to their cytotoxicity. Thus, understanding the mechanisms involved in DNA damage processing can not only enhance our knowledge of basic DNA repair mechanisms but may also be used to develop improved chemotherapeutic strategies to treat cancer. The high-mobility group box protein 1 (HMGB1) is a known nucleotide excision repair (NER) cofactor, and its family member HMGB3 has been implicated in chemoresistance in ovarian cancer. Here, we aim to understand the potential role(s) of HMGB3 in processing DNA damage. Methods: A potential role in NER was investigated using HMGB3 knockout human cell lines in response to UV damage. Subsequently, potential roles in DNA interstrand crosslink (ICL) and DNA double-strand break (DSB) repair were investigated using mutagenesis assays, metaphase spreads, foci formation, a variety of DNA repair assays, and TagSeq analyses in human cells. Results: Interestingly, unlike HMGB1, HMGB3 does not appear to play a role in NER. We found evidence to suggest that HMGB3 is involved in the processing of both DSBs and ICLs in human cells. Conclusions: These novel results elucidate a role for HMGB3 in DNA damage repair and, surprisingly, also indicate a distinct role of HMGB3 in DNA damage repair from that of HMGB1. These findings advance our understanding of the role of HMGB3 in chemotherapeutic drug resistance and as a target for new chemotherapeutic strategies in the treatment of cancer. Full article

This study demonstrates that rearing duration (14 and 30 days) and environmental salinity (0, 4, 8, and 12 parts per thousand (ppt) of NaCl) synergistically modulate osmoregulation and muscle texture in adult freshwater drums (Aplodinotus grunniens). Salinity significantly reduced the hepatosomatic index at 30 days (p < 0.05). Furthermore, serum biochemical indices were markedly affected. Higher salinity and prolonged rearing time decreased triglycerides, total cholesterol, and low-density lipoprotein (LDL), while high-density lipoprotein (HDL) levels increased at 14 days (p < 0.05), indicating improved lipid metabolism efficiency. Crucially, osmotic pressure remained stable across salinities at 14 days but exhibited a dose-dependent increase at 30 days (p < 0.05), driven primarily by elevated Na⁺ and Cl⁻ concentrations. Salinity (8–12 ppt) markedly enhanced water-holding capacity, reducing cooking loss (~58%), centrifugal loss (~74%), drip loss (~83%), and thaw loss (~84%) versus 0 ppt controls (p < 0.05). Concurrently, key texture parameters also significantly improved, as reflected by hardness, chewiness, resilience, and gumminess. These enhancements might be attributed to hyperosmotic stress-induced cellular dehydration and ionic strength-mediated protein cross-linking. Full article

The integration of emulsion gels in 3D food printing has emerged as a promising strategy to enhance both the structural fidelity and functional performance of printed foods. Emulsion gels, composed of proteins, polysaccharides, lipids, and their complexes, can provide tunable rheological and mechanical properties suitable for extrusion and shape retention. This review explores the formulation strategies, including phase behavior (O/W, W/O, and double emulsions); stabilization methods; and post-printing treatments, such as enzymatic, ionic, and thermal crosslinking. Advanced techniques, including ultrasound and high-pressure homogenization, are highlighted for improving gel network formation and retention of active compounds. Functional applications are addressed, with a focus on meat analogs, bioactive delivery systems, and personalized nutrition. Furthermore, the role of the oil content, interfacial engineering, and protein–polysaccharide interactions in improving print precision and post-processing performance is emphasized. Despite notable advances, challenges remain in scalability, regulatory compliance, and optimization of print parameters. The integration of artificial intelligence can also provide promising advances for smart design, predictive modeling, and automation of the 3D food printing workflow. Full article