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Journal of Food Protection Mar 2023Biofilm formation of Listeria monocytogenes in food processing environments cause potential source of cross-contamination to foodstuffs; hence, the control of biofilm is...
Biofilm formation of Listeria monocytogenes in food processing environments cause potential source of cross-contamination to foodstuffs; hence, the control of biofilm is currently addressed to find effective solutions for preventing biofilm formation or eliminating the established one. Forty-five strains of Listeria monocytogenes isolated from Pangasius fish-processing plants were studied for their capability to form a biofilm on 96-well microtiter plate by using the conventional crystal violet staining. Additionally, the inhibitory effect of biofilm formation by food additives including monascus pigment and ε-polylysine was examined. The average OD value showing biofilm mass of all 45 strains L. monocytogenes increased with an increasing temperature and time (p < 0.05). Monascus pigment and ε-polylysine significantly decreased biofilm formation by 80 ± 5.5% and 20 ± 5.9%, respectively, at the tested concentration (p < 0.05) Further, the effects of lysozyme (0.1 mg/mL) alone or in combination with slightly acidic hypochlorous water (SAHW) with 40 mg/L available chlorine or sodium hypochlorite (NaOCl) with 100 mg/L available chlorine against 7-d established biofilm of L. monocytogenes were investigated. The results indicated that slightly acidic hypochlorous water alone exhibited significant antibacterial activity (p < 0.05), decreasing the viable count by 5.2 ± 0.5 log CFU/mL. It seems that sequential treatment of lysozyme and SAHW showed an additional efficacy against biofilm of L. monocytogenes on polystyrene plate surface, reducing 70% of biomass of biofilm and 7.6 ± 0.3 log of biofilm viable cells (p < 0.05). Additionally, SAHW exhibited greater bactericidal activity against viable biofilm cells than NaOCl did. This result reveals that SAHW is a promising disinfectant agent against L. monocytogenes and the potential alternative to NaOCl in practice.
Topics: Animals; Listeria monocytogenes; Muramidase; Chlorine; Polylysine; Stainless Steel; Biofilms; Catfishes; Water; Colony Count, Microbial
PubMed: 36916551
DOI: 10.1016/j.jfp.2023.100044 -
Colloids and Surfaces. B, Biointerfaces Jul 2020We compared the proliferation and differentiation of mouse neuroblastoma Neuro 2A cell line on single layer graphene and glass substrates. Quantitative and qualitative...
We compared the proliferation and differentiation of mouse neuroblastoma Neuro 2A cell line on single layer graphene and glass substrates. Quantitative and qualitative analysis of the cell proliferation and differentiation were performed, considering also the effect of a common adhesion factor, namely polylysine. We observed that on graphene substrates the cells proliferate faster with respect to glass; additionally, the presence of the adhesion factor enhances the difference and, remarkably, boosts the cell differentiation on the graphene-based interface. To understand the mechanism underlying a different cell behavior on the same adhesion coating, we carried out a physicochemical investigation of the studied interfaces (glass and graphene, bare and polylysine coated) by several techniques. In particular, we employed infrared spectroscopy to gain information on polylysine conformation, and atomic force microscopy force-distance curves to study adhesion properties at the surface. The results indicate that polylysine has an enhanced binding affinity for graphene, as well as a different molecular arrangement on graphene with respect to glass. These properties act as surface cues to trigger the cell response.
Topics: Animals; Cell Adhesion; Cell Differentiation; Cell Proliferation; Coated Materials, Biocompatible; Graphite; Mice; Neuroblastoma; Polylysine; Tumor Cells, Cultured
PubMed: 32408266
DOI: 10.1016/j.colsurfb.2020.110991 -
International Journal of Biological... Dec 2019Of late, the demand for food-packaging materials, in particular, multifunction packaging materials that are biodegradable; antibacterial; have good mechanical and...
Of late, the demand for food-packaging materials, in particular, multifunction packaging materials that are biodegradable; antibacterial; have good mechanical and barrier properties; and are edible and transparent, has increased considerably. In this study, we prepared chitosan (CS)/ε-polylysine (PL) biofilms with different CS-to-PL ratios. We studied the preparation, mechanical properties, microstructures, thermal stability, transparency, water-vapor permeability, oil permeability, and antibacterial properties of the composite CS/PL biofilms. The results demonstrate that CS/PL biofilms are mechanically strong, have good thermal stability, high transparency, low water-vapor and oil permeability, and extensive antibacterial properties that act against Escherichia coli, Bacillus subtilis, and yeast. Therefore, we therefore conclude that CS/PL biofilms are promising food-packaging materials.
Topics: Anti-Infective Agents; Bacillus subtilis; Biofilms; Chitosan; Escherichia coli; Polylysine; Yeasts
PubMed: 31499113
DOI: 10.1016/j.ijbiomac.2019.09.035 -
Journal of the Mechanical Behavior of... Mar 2024The aim of this study was to synthesize a new bioactive and antibacterial composite by incorporating reactive calcium phosphate and antibacterial polylysine into a resin...
OBJECTIVE
The aim of this study was to synthesize a new bioactive and antibacterial composite by incorporating reactive calcium phosphate and antibacterial polylysine into a resin matrix and evaluate the effect of these fillers on structural analysis, degree of monomer conversion, mechanical properties, and bioactivity of these newly developed polypropylene based dental composites.
METHODOLOGY
Stock monomers were prepared by mixing urethane dimethacrylate and polypropylene glycol dimethacrylate and combined with 40 wt% silica to make experimental control (E-C). The other three experimental groups contained a fixed percentage of silica (40 wt%), monocalcium phosphate monohydrate, and β-tri calcium phosphate (5 wt% each) with varying amounts of polylysine (PL). These groups include E-CCP0 (0 wt% PL), E-CCP5 (5 wt% PL) and E-CCP10 (10 wt% PL). The commercial control used was Filtek™ Z250 3M ESPE. The degree of conversion was assessed by using Fourier transform infrared spectroscopy (FTIR). Compressive strength and Vicker's micro hardness testing were evaluated after 24 h of curing the samples. For bioactivity, prepared samples were placed in simulated body fluid for 0, 1, 7, and 28 days and were analyzed using a scanning electron microscope (SEM). SPSS 23 was used to analyze the data and one-way ANOVA and post hoc tukey's test were done, where the significant level was set ≤0.05.
RESULTS
Group E-C showed better mechanical properties than other experimental and commercial control groups. Group E-C showed the highest degree of conversion (72.72 ± 1.69%) followed by E-CCP0 (72.43 ± 1.47%), Z250 (72.26 ± 1.75%), E-CCP10 (71.07 ± 0.19%), and lowest value was shown by E-CCP5 (68.85 ± 7.23%). In shear bond testing the maximum value was obtained by E-C. The order in decreasing value of bond strength is E-C (8.13 ± 3.5 MPa) > Z250 (2.15 ± 1.1 MPa) > E-CCP10 (2.08 ± 2.1 MPa) > E-CCP5 (0.94 ± 0.8 MPa) > E-CCP0 (0.66 ± 0.2 MPa). In compressive testing, the maximum strength was observed by commercial control i.e., Z250 (210.36 ± 18 MPa) and E-C (206.55 ± 23 MPa), followed by E-CCP0 (108.06 ± 19 MPa), E-CCP5 (94.16 ± 9 MPa), and E-CCP10 (80.80 ± 13 MPa). The maximum number of hardness was shown by E-C (93.04 ± 8.23) followed by E-CCP0 (38.93 ± 9.21) > E-CCP10 (35.21 ± 12.31) > E-CCP5 (34.34 ± 12.49) > Z250 (25 ± 2.61). SEM images showed that the maximum apatite layer as shown by E-CCP10 and the order followed as E-CCP10 > E-CCP5 > E-CCP0 >Z250> E-C.
CONCLUSION
The experimental formulation showed an optimal degree of conversion with compromised mechanical properties when the polylysine percentage was increased. Apatite layer formation and polylysine at the interface may result in remineralization and ultimately lead to the prevention of secondary caries formation.
Topics: Polylysine; Composite Resins; Materials Testing; Calcium Phosphates; Methacrylates; Apatites; Silicon Dioxide; Anti-Bacterial Agents
PubMed: 38237205
DOI: 10.1016/j.jmbbm.2024.106398 -
Journal of Food Protection Mar 2022This study was conducted to determine the sterilization effect of a combination of high pressure thermal sterilization (HPTS) and ε-polylysine (ε-PL) on Bacillus...
ABSTRACT
This study was conducted to determine the sterilization effect of a combination of high pressure thermal sterilization (HPTS) and ε-polylysine (ε-PL) on Bacillus subtilis spores. The spores were treated with HPTS (550 MPa at 25, 65, and 75°C) and ε-PL at 0.1 and 0.3%. HPTS and ε-PL synergistically decreased the number of surviving spores and increased the release of the intracellular components in the spore suspension, with the maximal effects from treatment with 550 MPa at 75°C plus 0.3% ε-PL. Maximum fluidity and permeability of the cell inner membrane were observed with 550 MPa at 75°C plus 0.3% ε-PL. Changes in membrane lipids were detected from 3,000 to 2,800 cm-1 by Fourier transform infrared spectroscopy. The results provide new insights into the mechanism by which HPTS and ε-PL synergistically sterilize B. subtilis spores.
Topics: Bacillus subtilis; Polylysine; Spores, Bacterial; Sterilization
PubMed: 34788461
DOI: 10.4315/JFP-21-354 -
Food Chemistry Jul 2024Carvacrol is well-known natural antimicrobial compounds. However, its usage in fruit preservation is restricted owing to poor water solubility. Our study aims to address...
Carvacrol is well-known natural antimicrobial compounds. However, its usage in fruit preservation is restricted owing to poor water solubility. Our study aims to address this limitation by combining carvacrol with whey protein isolate (WPI) to form nanoemulsion and enhancing antimicrobial properties and stability of nanoemulsion through ε-polylysine addition, thereby improving their application in fruit preservation. The results indicated that the nanoemulsion exhibited a double-layer structure. The physicochemical properties and storage stability were found to be favorable under the conditions of WPI (0.3 wt% v/v), Carvacrol (0.5 % v/v), and ε-polylysine (0.3 wt% v/v). In addition, the nanoemulsion had inhibitory effects on Staphylococcus aureus, Escherichia coli, and Aspergillus niger at concentrations of minimal inhibition concentration (32, 32, and 200 μg/mL, respectively). In addition, during a 7-day storage period, the nanoemulsion effectively preserved mangoes. Therefore, nanoemulsion could serve as a candidate for control of postharvest mangoes spoilage and extend its period of storage.
Topics: Polylysine; Emulsions; Mangifera; Anti-Infective Agents; Escherichia coli; Cymenes
PubMed: 38402759
DOI: 10.1016/j.foodchem.2024.138831 -
The Journal of Physical Chemistry. B Apr 2023Poly-l-lysine (PLL) dendrimers have emerged as promising nanomaterials for gene/drug delivery, bioimaging, and biosensing due to their high efficacy and...
Poly-l-lysine (PLL) dendrimers have emerged as promising nanomaterials for gene/drug delivery, bioimaging, and biosensing due to their high efficacy and biocompatibility. In our previous works, we successfully synthesized two categories of PLL dendrimers with two different cores: the planar-shaped perylenediimide and the cubic-shaped polyhedral oligomeric silsesquioxanes. However, the effect of these two topologies on the PLL dendrimer structures is not clearly understood. In this work, we carried out in-depth investigations on the influence of core topologies on the PLL dendrimer structures using molecular dynamics simulations. We show that, even at high generations, the core topology affects the shape and branch distribution of the PLL dendrimer, which may further determine their performance. Moreover, our findings suggest that the core topology on the PLL dendrimer structures can be further designed and improved to fully exploit and utilize their potential in biomedical applications.
Topics: Models, Molecular; Molecular Conformation; Dendrimers; Polylysine; Water; Diffusion
PubMed: 37018047
DOI: 10.1021/acs.jpcb.2c08983 -
Journal of Experimental & Clinical... Jun 2021Immunotherapy is currently under intensive investigation as a potential breakthrough treatment option for glioblastoma. Given the anatomical and immunological... (Review)
Review
Immunotherapy is currently under intensive investigation as a potential breakthrough treatment option for glioblastoma. Given the anatomical and immunological complexities surrounding glioblastoma, lymphocytes that infiltrate the brain to develop durable immunity with memory will be key. Polyinosinic:polycytidylic acid, or poly(I:C), and its derivative poly-ICLC could serve as a priming or boosting therapy to unleash lymphocytes and other factors in the (immuno)therapeutic armory against glioblastoma. Here, we present a systematic review on the effects and efficacy of poly(I:C)/poly-ICLC for glioblastoma treatment, ranging from preclinical work on cellular and murine glioblastoma models to reported and ongoing clinical studies. MEDLINE was searched until 15 May 2021 to identify preclinical (glioblastoma cells, murine models) and clinical studies that investigated poly(I:C) or poly-ICLC in glioblastoma. A systematic review approach was conducted according to PRISMA guidelines. ClinicalTrials.gov was queried for ongoing clinical studies. Direct pro-tumorigenic effects of poly(I:C) on glioblastoma cells have not been described. On the contrary, poly(I:C) changes the immunological profile of glioblastoma cells and can also kill them directly. In murine glioblastoma models, poly(I:C) has shown therapeutic relevance as an adjuvant therapy to several treatment modalities, including vaccination and immune checkpoint blockade. Clinically, mostly as an adjuvant to dendritic cell or peptide vaccines, poly-ICLC has been demonstrated to be safe and capable of eliciting immunological activity to boost therapeutic responses. Poly-ICLC could be a valuable tool to enhance immunotherapeutic approaches for glioblastoma. We conclude by proposing several promising combination strategies that might advance glioblastoma immunotherapy and discuss key pre-clinical aspects to improve clinical translation.
Topics: Animals; Brain Neoplasms; Cancer Vaccines; Carboxymethylcellulose Sodium; Clinical Trials as Topic; Glioblastoma; Humans; Immune Checkpoint Inhibitors; Immunotherapy; Mice; Poly I-C; Polylysine
PubMed: 34172082
DOI: 10.1186/s13046-021-02017-2 -
Scientific Reports Jul 2020Antimicrobial peptides (AMPs) are components of immune defense in many organisms, including plants. They combat pathogens due to their antiviral, antifungal and...
Antimicrobial peptides (AMPs) are components of immune defense in many organisms, including plants. They combat pathogens due to their antiviral, antifungal and antibacterial properties, and are considered potential therapeutic agents. An example of AMP is Epsilon-Poly-L-lysine (EPL), a polypeptide formed by ~ 25 lysine residues with known antimicrobial activity against several human microbial pathogens. EPL presents some advantages such as good water solubility, thermal stability, biodegradability, and low toxicity, being a candidate for the control of phytopathogens. Our aim was to evaluate the antimicrobial activity of EPL against four phytobacterial species spanning different classes within the Gram-negative phylum Proteobacteria: Agrobacterium tumefaciens (syn. Rhizobium radiobacter), Ralstonia solanacearum, Xanthomonas citri subsp. citri (X. citri), and Xanthomonas euvesicatoria. The minimum inhibitory concentration (MIC) of the peptide ranged from 80 μg/ml for X. citri to 600 μg/ml for R. solanacearum and X. euvesicatoria. Two hours of MIC exposure led to pathogen death due to cell lysis and was enough for pathogen clearance. The protective and curative effects of EPL were demonstrated on tomato plants inoculated with X. euvesicatoria. Plants showed less disease severity when sprayed with EPL solution, making it a promising natural product for the control of plant diseases caused by diverse Proteobacteria.
Topics: Anti-Bacterial Agents; Gram-Negative Bacteria; Solanum lycopersicum; Plant Diseases; Polylysine
PubMed: 32647256
DOI: 10.1038/s41598-020-68262-1 -
Journal of Nanoscience and... Jan 2017Polylysine has broad biomedical applications, though little is known about its hemocompatibility. Here, we studied the influence of polylysine on human red blood cells...
Polylysine has broad biomedical applications, though little is known about its hemocompatibility. Here, we studied the influence of polylysine on human red blood cells (RBCs) and blood clotting. We observed the morphology and aggregation and determined the hemolysis of RBCs incubated with polylysine. Plasma coagulation in the presence of polylysine was evaluated by measuring the activated partial thromboplastin time (APTT) and prothrombin time (PT). Human whole blood coagulation in the presence of polylysine was evaluated with the thromboelastograph (TEG). We found that polylysine at 0.01 mg/mL did not result in RBC aggregation or morphological change, while polylysine at ≥ 0.1 mg/mL caused RBC aggregation. The RBCs did not lyze in the presence of 0.01–0.5 mg/mL of polylysine. Polylysine at 0.001 mg/mL did not cause a significantly different APTT from the control, while polylysine at ≥ 0.01 mg/mL caused a significantly higher APTT than the control. Polylysine at ≤ 0.1 mg/mL did not cause a significantly different PT from the control, while polylysine at 1 mg/mL caused a significantly higher PT than the control. TEG parameters for whole blood coagulation in the presence of 0.01 mg/mL polylysine were within the normal range; while polylysine ≥ 0.1 mg/mL caused one or more abnormal TEG parameters. From these results, the effect of polylysine on RBC aggregation and blood coagulation was concentration-dependent. The results provide important information for the biomedical applications of polylysine.
Topics: Blood Coagulation; Erythrocyte Aggregation; Erythrocytes; Hemolysis; Humans; Materials Testing; Polylysine
PubMed: 29620337
DOI: 10.1166/jnn.2017.12593