Search Results (405)

In the search for alternative protein sources, single cell proteins have gained increasing attention in recent years. Among them, proteins derived from yeast represent a promising but still underexplored option. To enable their application in food product design, their techno-functional properties must be understood. In order to investigate the impact of precipitation pH on their emulsion-stabilizing properties, yeast proteins from Saccharomyces cerevisiae were isolated via precipitation at different pH (pH 3.5 to 5) after cell disruption in the high-pressure homogenizer. Emulsions containing 5 wt% oil and ~1 wt% protein were analyzed for stability based on their droplet size distribution. Proteins precipitated at pH 3.5 stabilized the smallest oil droplets and prevented partitioning of the emulsion, outperforming proteins precipitated at higher pH values. It is hypothesized that precipitation under acidic conditions induces protein denaturation and thereby exposes hydrophobic regions that enhance adsorption at the oil–water interface and the stabilization of the dispersed oil phase. To investigate the stabilization mechanism, the molecular weight of the proteins was determined using SDS-PAGE, their solubility using Bradford assay, and their aggregation behavior using static laser scattering. Proteins precipitated at pH 3.5 possessed larger molecular weights, lower solubility, and a strong tendency to aggregate. Overall, the findings highlight the potential of yeast-derived proteins as bio-surfactants and suggest that pH-controlled precipitation can tailor their functionality in food formulations. Full article

Background/Objectives: Severe COVID-19 pneumonia damages alveolar type II cells and disrupts surfactant homeostasis, contributing to acute respiratory distress syndrome (ARDS). Surfactant proteins (SP-A, SP-B, SP-C, SP-D) are critical for reducing alveolar surface tension and for innate immune defense. We aimed to evaluate whether surfactant protein gene expression varies with the severity of COVID-19. Methods: Peripheral blood was collected from 122 adults with confirmed COVID-19, categorized as asymptomatic (no symptoms), mild (requiring hospitalization), or severe (requiring ICU admission). We quantified mRNA expression of surfactant protein genes (SFTPA1, SFTPA2, SFTPB, SFTPC, SFTPD) in blood cells using RT-qPCR. Relative expression was normalized to GAPDH and compared among the groups using the 2^−ΔΔCt method. Outliers (Ct values > 3 SD from the mean) were excluded before analysis. Results: Distinct surfactant gene expression patterns were markedly associated with disease severity. Transcripts of SFTPB and SFTPC decreased with increasing severity of the disease. Notably, SFTPC expression was ~49-fold higher in mild cases compared to asymptomatic COVID-19-positive patients (p < 0.0001), but then decreased by ~54-fold in severe cases relative to mild (p < 0.0001), returning to near-baseline levels. In contrast, SFTPA2 and SFTPD were dramatically upregulated in severe cases. SFTPA2 was ~50-fold higher in severe versus mild cases (p < 0.0001), and SFTPD was ~4346-fold higher in severe versus asymptomatic cases (p < 0.0001; ~9.6-fold higher than in mild). SFTPA1 showed only a modest ~1.4-fold decrease in severe cases (vs. mild). All noted differences remained statistically significant after outlier exclusion. Conclusions: COVID-19 severity is correlated with profound changes in surfactant gene expression in blood. Critically ill patients exhibit loss of key surfactant components (SP-B and SP-C transcripts) alongside an excessive SP-D response. These preliminary findings suggest an imbalance that may contribute to lung injury in severe disease. However, further validation is needed to establish surfactant proteins, such as SP-D, as biomarkers of COVID-19 severity. Full article

Background: Membrane proteins are preferentially solubilized with sodium dodecyl sulfate (SDS), which necessitates a purification protocol to deplete the surfactant prior to mass spectrometry analysis. However, maintaining solubility of intact membrane proteins is challenged in an SDS-free environment. SDS precipitation with potassium salts (KCl) offers a potentially viable workflow to deplete SDS and permit proteoform analysis. The purpose of this study is to devise a robust detergent-based protocol applicable for processing and analysis of intact membrane-associated proteoforms. Methods: The precipitation conditions impacting SDS removal from spinach chloroplasts and liver membrane proteome preparations were evaluated, capitalizing on optimization of pH (highly basic), addition of MS-compatible solubilizing additives (urea) and adjustment of the KCl to SDS ratio to maximize recovery and purity. Results: Characterization of the SDS-solubilized, KCl-precipitated spinach membrane preparation revealed multiple charge envelope MS spectra displaying high signal to noise, free of SDS adducts. Precipitation at pH 12 or with urea improved protein recovery and purity. Bottom-up analysis identified 1826 distinct liver protein groups from four independent SDS precipitation conditions. While precipitation at pH 8 without urea revealed a greater number of protein identifications by mass spectrometry, precipitation under highly basic conditions (pH 12) with urea provided higher membrane protein recovery and achieved the greatest number (732 of 1056) and largest percentage (69.3%) of membrane proteins identified in the SDS removal workflow. Conclusion: This workflow provides new opportunities for MS-based proteoform analysis by capitalizing on the benefits of SDS for protein extraction while maintaining high solubility and purity of intact proteins though KCl precipitation of the surfactant. Full article

Vulvar hygiene is an important part of general hygiene: the goals are to clear the vulvar area of microbial and cellular debris and vaginal and fecal secretions, ensure local comfort, provide natural levels of hydration, and protect the vulvar microbiota. There are few national and international guidelines on vulvar hygiene. We searched the PubMed database up until 30 November 2024, using logical combinations of the following terms: hygiene, washing, vulva, vulvar, microbiota, hydration, syndet, soap, detergent, water, and customs. The abstracts were reviewed, and potentially relevant full-text articles were retrieved and examined. The subregions of the vulva vary with regard to the presence of sweat and sebaceous glands, the keratin content, the water content, the pH, and the microbiota (notably Lactobacillus, Corynebacterium, Staphylococcus, and Prevotella). An alteration in the vulvar microbiota can cause an imbalance in the vaginal microbiota, and vice versa. Vaginal douching may have negative effects on vulvar microbiota. Hair removal might increase the risk of long-term dermatological complications. Repeated washing with water alone exposes the stratum corneum to damage, and washing with soap alters the stratum corneum proteins and lipids, increases skin water loss, and accentuates the risk of irritation. Syndet-based products have a mild detergent effect, promotion of hydration, a suitable pH for the vulvar area, and protection of the vulvar microbiota. Syndet-based products (containing a blend of surfactants, emollients, antioxidants, and buffering agents) appear to be the most appropriate for vulvar care. Full article

Citrus peel, a significant by-product of fruit processing, represents a rich source of carotenoids with strong antioxidant and health-promoting properties. The present study evaluated two green extraction techniques, cloud point extraction (CPE) and supramolecular solvent (SUPRAS)-based extraction, for carotenoids recovered from citron, orange, and tangerine peels. Whereas SUPRAS methods rely on a supramolecular solvent made of water, ethanol, and octanoic acid, CPE methods use surfactants and water, and both show a high potential to extract lipophilic components. CPE demonstrated superior efficiency in extracting total carotenoids and enhancing antioxidant activity, with orange peel extracts showing the highest concentrations. CPE and SUPRAS extracts were subsequently encapsulated using freeze-drying with chickpea protein isolate, achieving high encapsulation efficiencies (82.40–88.97%). The use of encapsulation technology is an effective strategy to protect carotenoids from environmental stressors. Color, morphological, and FTIR analyses confirmed the successful encapsulation and retention of carotenoids. Environmental impact was assessed using the EcoScale tool, revealing excellent sustainability for CPE (92 points) and satisfactory performance for SUPRAS-based extraction (70 points). The use of Generally Recognized As Safe (GRAS) solvents and plant-derived encapsulation materials makes this method highly suitable for clean-label product development across the food, cosmetic, and nutraceutical industries. In summary, the results point to a practical and sustainable approach to citrus waste valorization into valuable, health-promoting ingredients—supporting both circular economy goals and eco-friendly innovation. Full article

Essential oils (EOs) represent natural bioactive agents with broad applications; however, their industrial utilization is often hampered by inherent volatility and instability, which current encapsulation methods struggle to overcome due to limitations such as reliance on synthetic surfactants. Proteins, owing to their amphiphilic nature, serve as materials for EOs microencapsulation, particularly when chemically modified. Building upon our previous work demonstrating improved emulsifying properties of hemp seed protein isolate (HPI) through covalent modification with gallic acid (GA), this study investigated its efficacy for essential oil encapsulation. This study developed a novel microencapsulation system utilizing conjugates of HPI and GA for stabilizing six essential oils (lemon, grapefruit, camellia, fragrans, oregano, and mustard). The microcapsules exhibited encapsulation efficiencies (EE) ranging from 40% to 88%, with oregano oil demonstrating superior performance due to carvacrol’s amphiphilic surfactant properties. Advanced characterization techniques revealed that high-EE microcapsules displayed compact morphologies, enhanced thermal stability, and reduced surface oil localization. Release kinetics followed either the Peppas or Weibull model, with oregano microcapsules achieving sustained release via matrix erosion mechanisms. Antioxidant assays and antimicrobial tests demonstrated multifunctional efficacy, where oregano microcapsules exhibited the highest radical scavenging and antimicrobial activity. These findings establish HPI-GA conjugates as unique dual-functional emulsifier-encapsulants, offering a sustainable and effective platform to enhance EO stability and bioactivity, particularly for applications in food preservation and pharmaceutical formulations. Full article

It is becoming evident that the therapeutic effect of reawakening the immune response is to limit tumor cell growth and expansion. The use of immune checkpoint inhibitors, like blocking antibodies against programmed cell death receptor (PD) 1 and/or cytotoxic T lymphocyte antigen (CTLA) 4 alone or in combination with other drugs, has led to unexpected positive results in some tumors but not all. Several other molecules inhibiting lymphocyte antitumor effector subsets have been discovered in the last 30 years. Herein, we focus on the leukocyte-associated immunoglobulin (Ig)-like receptor 1 (LAIR1/CD305). LAIR1 represents a typical immunoregulatory molecule expressed on almost all leukocytes, unlike other regulatory receptors expressed on discrete leukocyte subsets. It bears two immunoreceptor tyrosine-based inhibitory motifs (ITIMs) in the intracytoplasmic protein domain involved in the downregulation of signals mediated by activating receptors. LAIR1 binds to several ligands, such as collagen I and III, complement component 1Q, surfactant protein D, adiponectin, and repetitive interspersed families of polypeptides expressed by erythrocytes infected with Plasmodium malariae. This would suggest LAIR1 involvement in several cell-to-cell interactions and possibly in metabolic regulation. The presence of both cellular and soluble forms of LAIR would indicate a fine regulation of the immunoregulatory activity, as happens for the soluble/exosome-associated forms of PD1 and CTLA4 molecules. As a consequence, LAIR1 appears to play a role in some autoimmune diseases and the immune response against tumor cells. The finding of LAIR1 expression on hematological malignancies, but also on some solid tumors, could open a rationale for the targeting of this molecule to treat neoplasia, either alone or in combination with other therapeutic options. Full article

An experimental model of acute pulmonary damage was developed based on the intravenous injection of the phospholipase A₂ (PLA₂)-rich venom of Pseudechis papuanus (Papuan black snake) in mice. Venom caused pulmonary edema, with the accumulation of a protein-rich exudate, as observed histologically and by analysis of bronchoalveolar lavage fluid (BALF). In parallel, venom induced an increase in all of the pulmonary mechanical parameters evaluated, without causing major effects in terms of tracheal and bronchial reactivity. These effects were abrogated by incubating the venom with the PLA₂ inhibitor varespladib, indicating that this hydrolytic enzyme is responsible for these alterations. The venom was cytotoxic to endothelial cells in culture, hydrolyzed phospholipids of a pulmonary surfactant, and reduced the activity of angiotensin-converting enzyme in the lungs. The pretreatment of mice with the nitric oxide synthase inhibitor L-NAME reduced the protein concentration in the BALF, whereas no effect was observed when mice were pretreated with inhibitors of cyclooxygenase (COX), tumor necrosis factor-α (TNF-α), bradykinin, or neutrophils. Based on these findings, it is proposed that the rapid pathological effect of this venom in the lungs is mediated by (a) the direct cytotoxicity of venom PLA₂ on cells of the capillary–alveolar barrier, (b) the degradation of surfactant factor by PLA₂, (c) the deleterious action of nitric oxide in pulmonary tissue, and (d) the cytotoxic action of free hemoglobin that accumulates in the lungs as a consequence of venom-induced intravascular hemolysis. Our findings offer clues on the mechanisms of pathophysiological alterations induced by PLA₂s in a variety of pulmonary diseases, including acute respiratory distress syndrome (ARDS). Full article

This study investigated the emulsifying and antioxidant properties of potato protein hydrolysates (PPHs) obtained through enzymatic hydrolysis with trypsin, aiming to utilize them as natural emulsifiers in 5 wt% fish-oil-in-water emulsions. Unfractionated and fractionated PPH fractions (>10 kDa, 5–10 kDa, 0.8–5 kDa, and <0.8 kDa) in combination with surfactants (Tween 20 or DATEM) were evaluated. Unfractionated PPH alone resulted in unstable emulsions; however, combining it with 67 wt% DATEM or Tween 20 improved physical stability. Smaller PPH fractions (<10 kDa) produced smaller droplet sizes (0.352–0.764 μm) with DATEM, whereas for Tween 20-stabilized emulsions, the smallest droplet size was observed with unfractionated PPH (1.051 ± 0.015 µm). Notably, the 5–10 kDa fraction exhibited the best oxidative stability when combined with Tween 20, likely due to its antioxidant properties. While further refinement is necessary to improve PPHs’ effectiveness as standalone emulsifiers, their potential is evident. Full article

Pollen allergy is rated as a major public health problem, causing significant morbidity and adversely affecting the quality of people’s lives. The airway epithelium serves as the first line of defense in the respiratory system, playing a crucial role in orchestrating immune responses to allergens. In this work, we studied the important transport steps in the major alder pollen allergen Aln g 1 through the human airway epithelium in comparison with those of the birch pollen allergen Bet v 1. Using fluorescence spectroscopy, we showed that both allergens can destroy liposomes with a composition modeling the adult human pulmonary surfactant. Using a polarized Calu-3 monolayer, we showed similar efficiencies of Aln g 1 and Bet v 1 transport through the artificial epithelial barrier. Using qPCR, we showed that Aln g 1 upregulates the expression of IL-33, TSLP, IL-1β, CXCL8 in epithelial cells, playing an important role in the sensitization process. The obtained results may improve our understanding of the primary sensitization mechanisms with the involvement of the PR-10 family of lipid-binding allergens. Full article

Thermosensitive hydrogel, as a smart polymer material, showed great potential for application in the field of wound repair due to its unique external temperature responsiveness and excellent biocompatibility. Chitosan, a natural macromolecular polysaccharide derived from the deacetylation of chitin, possessed not only strong interactions with biomolecules such as DNA, proteins, and lipids, but also unique biocompatibility and degradability. Chitosan-based thermosensitive hydrogels, prepared by compounding chitosan with surfactants, underwent sol–gel phase transitions at varying external temperatures, which provided an ideal healing environment for wounds. This comprehensive review was initiated by elucidating the sol–gel phase transformation mechanism underlying thermosensitive hydrogels and the intricate process of wound repair. In addition, this review provided a detailed overview of the prevalent types of chitosan-based thermosensitive hydrogels, highlighting their unique characteristics and applications in different types of wound repair. Finally, the challenges and development directions of chitosan-based thermosensitive hydrogels in wound repair were discussed, aiming to provide theoretical support and practical guidance for their future applications in wound healing. Full article

Tea saponins are excellent natural surfactants, and previous studies on their extraction from C. oleifera seed meals in subcritical water have mainly focused on the optimization of external extraction conditions. In order to achieve the efficient extraction of tea saponins in subcritical water, this study explores the influence of the composition-internal factors on the extraction rate of tea saponins. In this study, the composition of three C. oleifera seed meals purchased from Hubei, Hunan and Guizhou province and extraction rates of tea saponins, dissolution rates of reducing sugars and proteins from these C. oleifera seed meals were compared, and the results showed that reducing sugars and proteins were intrinsic components affecting extraction rates of tea saponins in subcritical water. The simulation system involving tea saponins, whey protein isolate (WPI), and glucose in subcritical water showed that WPI reduced the content of tea saponins through the Maillard reaction, and glucose inhibited the participation of tea saponins in the Maillard reaction. The above mechanism was verified using alkaline protease, which changed the content of reducing sugars and proteins in the C. oleifera seed meal purchased from Hubei province, and provided guidance for achieving the efficient extraction of tea saponins. Full article

Interstitial lung disease (ILD) prevalence and survival are increasing due to improvement in scientific research together with clinical complications typical of advanced disease. Lung cancer (LC) is described as a possible event occurring in lung parenchyma in the context of fibrotic abnormalities that worsen patients’ prognosis. This growth of malignant cells on a fibrotic background has also been called scar-cinoma. For this reason, not only an early diagnosis but also personalized decisions on the best treatment approach should be considered for each patient in a multidisciplinary discussion, since in some cases chemotherapy or surgery could be detrimental for patients with pulmonary fibrosis. LC and lung fibrosis may share common pathogenetic mechanisms like an altered healing process in response to repeated tissue damage from environmental exposure in genetically susceptible individuals. Smoking history and air pollution together with mutations in telomere and surfactant protein genes lead to the production of cytokines and nitro derivatives in the microenvironment that facilitate the carcinomatous transformation during fibrogenesis. The evolution of LC therapy and the implementation of immunotherapy acting on targetable immune checkpoints have raised interest in evaluating ILD-LC actionable mutations. The main pathogenetic mechanisms, clinical presentations and treatment implications are presented in this review. Full article

Background: Immunological and rheological properties are important factors of the surfactant protein (SP) family, whose impact on tumorigenesis is not yet known, although some SPs have been identified as tumor marker candidates for various malignancies. This study describes the detection of the two surfactant family proteins SP-G and PLUNC in healthy glottis, the presence of SP-G in glottic cancer, and the in vitro tissue regeneration potential of SP-G and PLUNC on epithelial cells. Methods: The expression and distribution of SP-G and PLUNC were investigated immunohistochemically in squamous cell carcinomas of the vocal folds. The expression of both proteins was analyzed by Western blot in micro-dissected healthy vocal fold mucosa from body donors. The hypopharyngeal squamous carcinoma cell line (FaDu) was used as an in vitro model for wound healing experiments with Electric cell–substrate impedance sensing (ECIS). Results: The results show the presence of SP-G and PLUNC in epithelial cells of the healthy vocal folds and the submucosal glands of the vestibular folds. SP-G was detected in squamous cell carcinomas of the vocal folds. SP-G and PLUNC show accelerated wound healing of FaDu cells in vitro. Conclusions: SP-G and PLUNC were first detected in the vocal fold of the human larynx. SP-G shows a distinct presence in glottic carcinoma, whose relevance needs to be determined in future studies. SP-G and PLUNC exhibit a positive influence on the repair mechanisms of epithelial lesions of the glottis. The data presented form the basis for follow-up studies focusing on the impact of SP-G in glottic cancer development and the potentially meaningful clinical effect of SP-G and PLUNC on tissue repair of the human vocal fold. Full article

Nutraceuticals are gaining research interest due to their beneficial potential and their use to counter the impact of emerging contaminants on natural ecosystems. Particularly, during the COVID-19 pandemic, the use of personal hygiene/care products and disinfectants increased significantly. These products contain several substances in their formulations, including surfactants, which have proven to be hazardous to the entire aquatic ecosystem. In the present study, bergamot (Citrus bergamia) peel extract was used as a nutraceutical to counteract the toxicity of sodium lauryl sulphate (SLS), a common anionic detergent with antimicrobial activity. Specimens of Mytilus galloprovincialis, were exposed to SLS (0.01 mg/L), bergamot peels’ extract (BRG: 5 mg/L), and their mixture for 14 days. The cellular and physiological alterations in haemocytes, digestive gland (DG) and gill cells were analysed. The analyses included cell viability of haemocytes and DG cells (trypan blue exclusion assay and the neutral red retention test); the ability of DG cells to regulate their volume (RVD); haemocyte phagocytic activity; expression of genes involved in antioxidant response (Cu/ZnSOD, MnSOD, Hsp70, and CYP4Y) on gills and DG; the energy efficiency of the organism through byssus production; and the measurement of key macromolecules, including total lipid and fatty acid content, total protein, tocopherols and carotenoids, which play a key role in maintaining physiological and metabolic functions in the organism. Overall, significant differences emerged between the control (CTR) and treated groups, with the CTR and BRG groups resembling each other, while the SLS-treated groups showed significant alterations. Meanwhile, the groups exposed to the combination showed a recovery, suggesting the potential beneficial effect of the BRG. Full article