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Meat Science Aug 2024This study investigated the synergistic effects of ε-poly- L -lysine (ε-PL) and lysozyme against P. aeruginosa and L. monocytogenes biofilms. Single-culture biofilms...
This study investigated the synergistic effects of ε-poly- L -lysine (ε-PL) and lysozyme against P. aeruginosa and L. monocytogenes biofilms. Single-culture biofilms of two bacteria were formed on silicone rubber (SR), stainless steel (SS), and beef surfaces and then treated with lysozyme (0.05-5 mg/mL) and ε-PL at minimum inhibitory concentrations (MICs) of 1 to 4 separately or in combination. On the SR surface, P. aeruginosa biofilm was reduced by 1.4 and 1.9 log CFU/cm within 2 h when treated with lysozyme (5 mg/mL) and ε-PL (4 MIC), respectively, but this reduction increased significantly to 4.1 log CFU/cm (P < 0.05) with the combined treatment. On beef surface, P. aeruginosa and L. monocytogenes biofilm was reduced by 4.2-5.0, and 3.3-4.2 log CFU/g when lysozyme was combined with 1, 2, and 4 MIC of ε-PL at 25 °C, respectively. Compared to 5 mg/mL lysozyme alone, the combined treatment with 1, 2, and 4 MIC of ε-PL on beef surface achieved additional reduction against P. aeruginosa biofilm of 0.5, 0.8, and 0.7 log CFU/g, respectively, at 25 °C. In addition, 0.25 mg/mL lysozyme and 0.5 MIC of ε-PL significantly (P < 0.05) suppressed the quorum-sensing (agrA) and virulence-associated (hlyA and prfA) genes of L. monocytogenes.
Topics: Pseudomonas aeruginosa; Muramidase; Biofilms; Animals; Listeria monocytogenes; Polylysine; Cattle; Drug Synergism; Microbial Sensitivity Tests; Red Meat; Food Microbiology; Stainless Steel; Anti-Bacterial Agents
PubMed: 38749270
DOI: 10.1016/j.meatsci.2024.109534 -
Biomaterials Science Jun 2024The treatment of various types of wounds such as dermal wounds, multidrug resistant bacteria-infected wounds, and chronic diabetic wounds is one of the critical... (Review)
Review
The treatment of various types of wounds such as dermal wounds, multidrug resistant bacteria-infected wounds, and chronic diabetic wounds is one of the critical challenges facing healthcare systems. Delayed wound healing can impose a remarkable burden on patients and health care professionals. In this case, given their unique three-dimensional porous structure, biocompatibility, high hydrophilicity, capability to provide a moist environment while absorbing wound exudate, permeability to both gas and oxygen, and tunable mechanical properties, hydrogels with antibacterial function are one of the most promising candidates for wound healing applications. Polylysine is a cationic polymer with the advantages of inherent antibacterial properties, biodegradability, and biocompatibility. Therefore, its utilization to engineer antibacterial hydrogels for accelerating wound healing is of great interest. In this review, we initially discuss polylysine properties, and then focus on the most recent advances in polylysine-containing hydrogels (since 2016) prepared using various chemical and physical crosslinking methods for hemostasis and wound healing applications. Finally, the challenges and future directions in the engineering of these antibacterial hydrogels for wound healing are discussed.
Topics: Hydrogels; Wound Healing; Polylysine; Anti-Bacterial Agents; Humans; Animals; Hemostatics; Hemostasis
PubMed: 38747970
DOI: 10.1039/d3bm01792c -
ACS Applied Materials & Interfaces May 2024Interleukin-6 (IL-6) is known to play a critical role in the progression of inflammatory diseases such as cardiovascular disease, cancer, sepsis, viral infection,...
Interleukin-6 (IL-6) is known to play a critical role in the progression of inflammatory diseases such as cardiovascular disease, cancer, sepsis, viral infection, neurological disease, and autoimmune diseases. Emerging diagnostic and prognostic tools, such as optical nanosensors, experience challenges in translation to the clinic in part due to protein corona formation, dampening their selectivity and sensitivity. To address this problem, we explored the rational screening of several classes of biomolecules to be employed as agents in noncovalent surface passivation as a strategy to screen interference from nonspecific proteins. Findings from this screening were applied to the detection of IL-6 by a fluorescent-antibody-conjugated single-walled carbon nanotube (SWCNT)-based nanosensor. The IL-6 nanosensor exhibited highly sensitive and specific detection after passivation with a polymer, poly-l-lysine, as demonstrated by IL-6 detection in human serum within a clinically relevant range of 25 to 25,000 pg/mL, exhibiting a limit of detection over 3 orders of magnitude lower than prior antibody-conjugated SWCNT sensors. This work holds potential for the rapid and highly sensitive detection of IL-6 in clinical settings with future application to other cytokines or disease-specific biomarkers.
Topics: Interleukin-6; Humans; Nanotubes, Carbon; Biosensing Techniques; Limit of Detection; Polylysine
PubMed: 38745465
DOI: 10.1021/acsami.4c02711 -
Journal of Food Protection Jul 2024Salmonella is capable of surviving dehydration within various foods, such as dried fruit. Dried fruit, including apple slices, have been the subject of product recalls...
Salmonella is capable of surviving dehydration within various foods, such as dried fruit. Dried fruit, including apple slices, have been the subject of product recalls due to contamination with Salmonella. A study was conducted to determine the fate of Salmonella on apple slices, following immersion in three antimicrobial solutions (viz., ε-polylysine [epsilon-polylysine or EP], sodium bisulfate [SBS], or peracetic acid [PAA]), and subsequent hot air dehydration. Gala apples were aseptically cored and sliced into 0.4 cm thick rings, bisected, and inoculated with a five-strain composite of desiccation-resistant Salmonella, to a population of 8.28 log CFU/slice. Slices were then immersed for 2 min in various concentrations of antimicrobial solutions, including EP (0.005, 0.02, 0.05, and 0.1%), SBS (0.05, 0.1, 0.2, and 0.3%), PAA (18 or 42 ppm), or varying concentrations of PAA + EP, and then dehydrated at 60°C for 5 h. Salmonella populations in positive control samples (inoculated apple slices washed in sterile water) declined by 2.64 log after drying. In the present study, the inactivation of Salmonella, following EP and SBS treatments, increased with increasing concentrations, with maximum reductions of 3.87 and 6.20 log (with 0.1 and 0.3% of the two compounds, respectively). Based on preliminary studies, EP concentrations greater than 0.1% did not result in lower populations of Salmonella. Pretreatment washes with either 18 or 42 ppm of PAA inactivated Salmonella populations by 4.62 and 5.63 log, respectively, following desiccation. Combining PAA with up to 0.1% EP induced no greater population reductions of Salmonella than washing with PAA alone. The addition of EP to PAA solutions appeared to destabilize PAA concentrations, reducing its biocidal efficacy. These results may provide antimicrobial predrying treatment alternatives to promote the reduction of Salmonella during commercial or consumer hot air drying of apple slices.
Topics: Malus; Peracetic Acid; Salmonella; Polylysine; Food Microbiology; Humans; Colony Count, Microbial; Sulfates; Food Preservation; Dose-Response Relationship, Drug; Desiccation; Food Contamination; Food Handling; Consumer Product Safety
PubMed: 38734414
DOI: 10.1016/j.jfp.2024.100297 -
Nature Communications May 2024In this randomized phase II clinical trial, we evaluated the effectiveness of adding the TLR agonists, poly-ICLC or resiquimod, to autologous tumor lysate-pulsed... (Randomized Controlled Trial)
Randomized Controlled Trial
In this randomized phase II clinical trial, we evaluated the effectiveness of adding the TLR agonists, poly-ICLC or resiquimod, to autologous tumor lysate-pulsed dendritic cell (ATL-DC) vaccination in patients with newly-diagnosed or recurrent WHO Grade III-IV malignant gliomas. The primary endpoints were to assess the most effective combination of vaccine and adjuvant in order to enhance the immune potency, along with safety. The combination of ATL-DC vaccination and TLR agonist was safe and found to enhance systemic immune responses, as indicated by increased interferon gene expression and changes in immune cell activation. Specifically, PD-1 expression increases on CD4+ T-cells, while CD38 and CD39 expression are reduced on CD8+ T cells, alongside an increase in monocytes. Poly-ICLC treatment amplifies the induction of interferon-induced genes in monocytes and T lymphocytes. Patients that exhibit higher interferon response gene expression demonstrate prolonged survival and delayed disease progression. These findings suggest that combining ATL-DC with poly-ICLC can induce a polarized interferon response in circulating monocytes and CD8+ T cells, which may represent an important blood biomarker for immunotherapy in this patient population.Trial Registration: ClinicalTrials.gov Identifier: NCT01204684.
Topics: Humans; Dendritic Cells; Glioma; Female; Male; Interferons; Middle Aged; Cancer Vaccines; CD8-Positive T-Lymphocytes; Poly I-C; Adult; Toll-Like Receptors; Imidazoles; Aged; Vaccination; Monocytes; Brain Neoplasms; CD4-Positive T-Lymphocytes; Immunotherapy; Toll-Like Receptor Agonists; Carboxymethylcellulose Sodium; Polylysine
PubMed: 38719809
DOI: 10.1038/s41467-024-48073-y -
ACS Applied Materials & Interfaces May 2024Indocyanine green (ICG), as the sole near-infrared dye FDA-approved, is limited in biomedical applications because of its poor photostability, lack of targeting, and...
Indocyanine green (ICG), as the sole near-infrared dye FDA-approved, is limited in biomedical applications because of its poor photostability, lack of targeting, and rapid removal in vivo. Herein, we presented a nanoformulation of poly-l-lysine-indocyanine green-hyaluronic acid (PIH) and demonstrated that it can image orthodox endometriosis (EM) lesions with a negative contrast. The PIH nanocluster, with an average diameter of approximately 200 nm, exhibited improved fluorescence photostability and antioxidant ability compared to free ICG. In the in vivo imaging, EM lesions were visualized, featuring apparent voids and clear boundaries. After colocalizing with the green fluorescent protein, we concluded that the contrast provided by PIH peaked at 4 h postinjection and was observable for at least 8 h. The negative contrast, clear boundaries, and enhanced observable time might be due to the low permeation of PIH to lesions and the enhanced retention on the surfaces of lesions. Thus, our findings suggest an ICG-based nanoprobe with the potential to diagnose abdominal diseases.
Topics: Indocyanine Green; Endometriosis; Female; Animals; Hyaluronic Acid; Humans; Mice; Polylysine; Contrast Media; Nanoparticles; Optical Imaging; Fluorescent Dyes
PubMed: 38716677
DOI: 10.1021/acsami.4c04131 -
Applied Biochemistry and Biotechnology May 2024The role of food additives is to preserve food by extending shelf life and limiting harmful microorganism proliferation. They prevent spoilage by enhancing the taste and... (Review)
Review
The role of food additives is to preserve food by extending shelf life and limiting harmful microorganism proliferation. They prevent spoilage by enhancing the taste and safety of food by utilizing beneficial microorganisms and their antimicrobial metabolites. Current advances in food preservation and processing utilize green technology principles for green preservative formulation, enhancing nutrition and supplying essential micronutrients safely, while also improving quality, packaging, and food safety. Encapsulation is gaining attention for its potential to protect delicate materials from oxidative degradation and extend their shelf life, thereby ensuring optimal nutrient uptake. Nanoencapsulation of bioactive compounds has significantly improved the food, pharmaceutical, agriculture, and nutraceutical industries by protecting antioxidants, vitamins, minerals, and essential fatty acids by controlling release and ensuring delivery to specific sites in the human body. This emerging area is crucial for future industrial production, improving the sensory properties of foods like color, taste, and texture. Research on encapsulated bioactive compounds like bacteriocins, LAB, natamycin, polylysine, and bacteriophage is crucial for their potential antioxidant and antimicrobial activities in food applications and the food industry. This paper reviews nanomaterials used as food antimicrobial carriers, including nanoemulsions, nanoliposomes, nanoparticles, and nanofibers, to protect natural food antimicrobials from degradation and improve antimicrobial activity. This review discusses nanoencapsulation techniques for biopreservative agents like nisin, poly lysine, and natamycin, focusing on biologically-derived polymeric nanofibers, nanocarriers, nanoliposomes, and polymer-stabilized metallic nanoparticles. Nanomaterials, in general, improve the dispersibility, stability, and availability of bioactive substances, and this study discusses the controlled release of nanoencapsulated biopreservative agents.
PubMed: 38713338
DOI: 10.1007/s12010-024-04943-1 -
Carbohydrate Polymers Aug 2024The biggest obstacle to treating wound healing continues to be the production of simple, inexpensive wound dressings that satisfy the demands associated with full...
The biggest obstacle to treating wound healing continues to be the production of simple, inexpensive wound dressings that satisfy the demands associated with full process of repair at the same time. Herein, a series of injectable composite hydrogels were successfully prepared by a one-pot method by utilizing the Schiff base reaction as well as hydrogen bonding forces between hydroxypropyl chitosan (HCS), ε-poly-l-lysine (EPL), and 2,3,4-trihydroxybenzaldehyde (TBA), and multiple cross-links formed by the reversible coordination between iron (III) and pyrogallol moieties. Notably, hydrogel exhibits excellent physicochemical properties, including injectability, self-healing, water retention, and adhesion, which enable to fill irregular wounds for a long period, providing a suitable moist environment for wound healing. Interestingly, the excellent hemostatic properties of the hydrogel can quickly stop bleeding and avoid the serious sequelae of massive blood loss in acute trauma. Moreover, the powerful antimicrobial and antioxidant properties also protect against bacterial infections and reduce inflammation at the wound site, thus promoting healing at all stages of the wound. The study of biohydrogel with multifunctional integration of wound treatment and smart medical treatment is clarified by this line of research.
Topics: Wound Healing; Hydrogels; Chitosan; Polylysine; Animals; Hemostatics; Anti-Bacterial Agents; Mice; Staphylococcus aureus; Escherichia coli; Humans; Anti-Infective Agents; Schiff Bases; Rats
PubMed: 38710549
DOI: 10.1016/j.carbpol.2024.122135 -
European Biophysics Journal : EBJ May 2024Unicellular organisms such as yeast can survive in very different environments, thanks to a polysaccharide wall that reinforces their extracellular membrane. This wall...
Unicellular organisms such as yeast can survive in very different environments, thanks to a polysaccharide wall that reinforces their extracellular membrane. This wall is not a static structure, as it is expected to be dynamically remodeled according to growth stage, division cycle, environmental osmotic pressure and ageing. It is therefore of great interest to study the mechanics of these organisms, but they are more difficult to study than other mammalian cells, in particular because of their small size (radius of a few microns) and their lack of an adhesion machinery. Using flat cantilevers, we perform compression experiments on single yeast cells (S. cerevisiae) on poly-L-lysine-coated grooved glass plates, in the limit of small deformation using an atomic force microscope (AFM). Thanks to a careful decomposition of force-displacement curves, we extract local scaling exponents that highlight the non-stationary characteristic of the yeast behavior upon compression. Our multi-scale nonlinear analysis of the AFM force-displacement curves provides evidence for non-stationary scaling laws. We propose to model these phenomena based on a two-component elastic system, where each layer follows a different scaling law..
Topics: Saccharomyces cerevisiae; Elasticity; Models, Biological; Microscopy, Atomic Force; Polylysine; Compressive Strength
PubMed: 38703210
DOI: 10.1007/s00249-024-01710-2 -
BMC Oral Health May 2024To evaluate the antibacterial effectiveness of a combination of ε-poly-L-lysine (ε-PL), funme peptide (FP) as well as domiphen against oral pathogens, and assess the... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
To evaluate the antibacterial effectiveness of a combination of ε-poly-L-lysine (ε-PL), funme peptide (FP) as well as domiphen against oral pathogens, and assess the efficacy of a BOP® mouthwash supplemented with this combination in reducing halitosis and supragingival plaque in a clinical trial.
MATERIALS AND METHODS
The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the compound against Fusobacterium nucleatum, Porphyromonas gingivalis, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans were determined by the gradient dilution method. Subsequently, the CCK-8 assay was used to detect the toxicity of mouthwash on human gingival fibroblastst, and the effectiveness in reducing halitosis and supragingival plaque of the mouthwash supplemented with the combination was analyzed by a randomized, double-blind, parallel-controlled clinical trial.
RESULTS
The combination exhibited significant inhibitory effects on tested oral pathogens with the MIC < 1.56% (v/v) and the MBC < 3.13% (v/v), and the mouthwash containing this combination did not inhibit the viability of human gingival fibroblasts at the test concentrations. The clinical trial showed that the test group displayed notably lower volatile sulfur compounds (VSCs) at 0, 10, 24 h, and 7 d post-mouthwash (P < 0.05), compared with the baseline. After 7 days, the VSC levels of the and control groups were reduced by 50.27% and 32.12%, respectively, and notably cutting severe halitosis by 57.03% in the test group. Additionally, the Plaque Index (PLI) of the test and control group decreased by 54.55% and 8.38%, respectively, and there was a significant difference in PLI between the two groups after 7 days (P < 0.01).
CONCLUSIONS
The combination of ε-PL, FP and domiphen demonstrated potent inhibitory and bactericidal effects against the tested oral pathogens, and the newly formulated mouthwash added with the combination exhibited anti-dental plaque and anti-halitosis properties in a clinical trial and was safe.
TRIAL REGISTRATION
The randomized controlled clinical trial was registered on Chinese Clinical Trial Registry (No. ChiCTR2300073816, Date: 21/07/2023).
Topics: Humans; Halitosis; Mouthwashes; Dental Plaque; Double-Blind Method; Male; Female; Polylysine; Adult; Microbial Sensitivity Tests; Young Adult; Anti-Bacterial Agents; Porphyromonas gingivalis; Fusobacterium nucleatum; Fibroblasts; Peptides; Aggregatibacter actinomycetemcomitans; Streptococcus mutans
PubMed: 38702623
DOI: 10.1186/s12903-024-04255-0