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International Journal of Molecular... Oct 2021In this study, ε-polylysine and calcium phosphate precipitation (CPP) methods were employed to induce antibacterial effects and dentin tubule occlusion. Antibacterial...
In this study, ε-polylysine and calcium phosphate precipitation (CPP) methods were employed to induce antibacterial effects and dentin tubule occlusion. Antibacterial effects of ε-polylysine were evaluated with broth dilution assay against CPP solution from MCPM, DCPD, and TTCP was prepared. Four concentrations of ε-polylysine(ε-PL) solutions (0.125%, 0.25%, 0.5%, 1%) were prepared. Dentin discs were prepared from recently extracted human third molars. Dentin discs were incubated with (ATCC 33277) bacterial suspension (ca. 10 bacteria) containing Brain Heart Infusion medium supplemented with 0.1 g/mL Vitamin K, 0.5 mg/mL hemin, 0.4 g/mL L-cysteine in anaerobic jars (37 °C) for 7 days to allow for biofilm formation. -infected dentin specimens were randomly divided into four groups: CPP + 0.125% ε-PL, CPP + 0.25% ε-PL, CPP + 0.5% ε-PL, CPP + 1% ε-PL. On each dentin specimen, CPP solution was applied followed by polylysine solution with microbrush and immersed in artificial saliva. Precipitate formation, antibacterial effects, and occlusion of dentinal tubules were characterized in vitro over up to 72 h using scanning electron microscopy. ε-PL showed 34.97% to 61.19% growth inhibition levels against () after 24 h of incubation. On -infected dentin specimens, DCPD + 0.25% ε-PL, and DCPD + 0.5% ε-PL groups showed complete bacterial inhibition and 78.6% and 98.1% dentin tubule occlusion, respectively ( < 0.001). The longitudinal analysis on fractured dentin samples in DCPD and TTCP groups revealed deeply penetrated hydroxyapatite-like crystal formations in dentinal tubules after 72 h of incubation in artificial saliva.
Topics: Anti-Bacterial Agents; Calcium Phosphates; Dentin; Dentin Sensitivity; Humans; Microbial Sensitivity Tests; Polylysine; Spectrum Analysis; Surface Properties
PubMed: 34639022
DOI: 10.3390/ijms221910681 -
International Journal of Biological... Apr 2022A gellan-polylysine (GPL) fiber was prepared by wet spinning molding with gellan solution containing glucose, soybean peptide, fish collagen peptide as spinning liquid,...
A gellan-polylysine (GPL) fiber was prepared by wet spinning molding with gellan solution containing glucose, soybean peptide, fish collagen peptide as spinning liquid, and ε-poly-l-lysine as fixative liquid. Results showed that the material addition order affects the spinning and an acceptable material addition order was as follows: soybean peptides →glucose → fish collagen peptides. The mechanical strength of the GPL fiber decreased with the collagen peptide titer and the fiber strength can reach 0.99 cN/dtex. In addition, the GPL fiber showed comparable water absorption capacity. The GPL fiber demonstrated good antibacterial properties against Escherichia coli and Staphylococcus aureus. The GPL fiber also had no cytotoxicity on mouse embryo fibroblast L-929 cells and could effectively promote wound healing for rats. As a result, the bifunctional edible GPL fiber is potentially used as a military and rescue emergency equipment.
Topics: Animals; Anti-Bacterial Agents; Escherichia coli; Mice; Polylysine; Polysaccharides, Bacterial; Rats; Staphylococcus aureus
PubMed: 35120940
DOI: 10.1016/j.ijbiomac.2022.01.187 -
Microbial Cell Factories Apr 2022AdpA is a global regulator of morphological differentiation and secondary metabolism in Streptomyces, but the regulatory roles of the Streptomyces AdpA family on the...
BACKGROUND
AdpA is a global regulator of morphological differentiation and secondary metabolism in Streptomyces, but the regulatory roles of the Streptomyces AdpA family on the biosynthesis of the natural product ε-poly-L-lysine (ε-PL) remain unidentified, and few studies have focused on increasing the production of ε-PL by manipulating transcription factors in Streptomyces.
RESULTS
In this study, we revealed the regulatory roles of different AdpA homologs in ε-PL biosynthesis and morphological differentiation and effectively promoted ε-PL production and sporulation in Streptomyces albulus NK660 by heterologously expressing adpA from S. neyagawaensis NRRLB-3092 (adpA). First, we identified a novel AdpA homolog named AdpA in S. albulus NK660 and characterized its function as an activator of ε-PL biosynthesis and morphological differentiation. Subsequently, four heterologous AdpA homologs were selected to investigate their phylogenetic relationships and regulatory roles in S. albulus, and AdpA was demonstrated to have the strongest ability to promote both ε-PL production and sporulation among these five AdpA proteins. The ε-PL yield of S. albulus heterologously expressing adpA was approximately 3.6-fold higher than that of the control strain. Finally, we clarified the mechanism of AdpA in enhancing ε-PL biosynthesis and its effect on ε-PL polymerization degree using real-time quantitative PCR, microscale thermophoresis and MALDI-TOF-MS. AdpA was purified, and its seven direct targets, zwf, tal, pyk2, pta, ack, pepc and a transketolase gene (DC74_2409), were identified, suggesting that AdpA may cause the redistribution of metabolic flux in central metabolism pathways, which subsequently provides more carbon skeletons and ATP for ε-PL biosynthesis in S. albulus.
CONCLUSIONS
Here, we characterized the positive regulatory roles of Streptomyces AdpA homologs in ε-PL biosynthesis and their effects on morphological differentiation and reported for the first time that AdpA promotes ε-PL biosynthesis by affecting the transcription of its target genes in central metabolism pathways. These findings supply valuable insights into the regulatory roles of the Streptomyces AdpA family on ε-PL biosynthesis and morphological differentiation and suggest that AdpA may be an effective global regulator for enhanced production of ε-PL and other valuable secondary metabolites in Streptomyces.
Topics: Phylogeny; Polylysine; Secondary Metabolism; Streptomyces
PubMed: 35397580
DOI: 10.1186/s12934-022-01785-6 -
Journal of Nanobiotechnology May 2024Approximately 80 percent of the total RNA in cells is ribosomal RNA (rRNA), making it an abundant and inexpensive natural source of long, single-stranded nucleic acid,...
Approximately 80 percent of the total RNA in cells is ribosomal RNA (rRNA), making it an abundant and inexpensive natural source of long, single-stranded nucleic acid, which could be used as raw material for the fabrication of molecular origami. In this study, we demonstrate efficient and robust construction of 2D and 3D origami nanostructures utilizing cellular rRNA as a scaffold and DNA oligonucleotide staples. We present calibrated protocols for the robust folding of contiguous shapes from one or two rRNA subunits that are efficient to allow folding using crude extracts of total RNA. We also show that RNA maintains stability within the folded structure. Lastly, we present a novel and comprehensive analysis and insights into the stability of RNA:DNA origami nanostructures and demonstrate their enhanced stability when coated with polylysine-polyethylene glycol in different temperatures, low Mg concentrations, human serum, and in the presence of nucleases (DNase I or RNase H). Thus, laying the foundation for their potential implementation in emerging biomedical applications, where folding rRNA into stable structures outside and inside cells would be desired.
Topics: RNA, Ribosomal; Nucleic Acid Conformation; Nanostructures; Humans; RNA Folding; DNA; Polylysine; Polyethylene Glycols
PubMed: 38698435
DOI: 10.1186/s12951-024-02489-2 -
International Journal of Biological... Dec 2023A feasible approach to enhance the antimicrobial efficacy of ε-polylysine (PL) in applications is to form delivery complexes with delicate structures and good...
ε-Polylysine and soybean protein isolate form nanoscale to microscale electrostatic complexes in solution: properties, interactions and as antimicrobial edible coatings on citrus.
A feasible approach to enhance the antimicrobial efficacy of ε-polylysine (PL) in applications is to form delivery complexes with delicate structures and good dispersion properties. This work aims to study the multiscale structures, properties and interactions, and edible coating applications of the electrostatic complex formed by PL and soy protein isolate (SPI). When the mass ratio of SPI to PL (SE) was between 5 and 15, especially 11, microscale solid-liquid phase separation occurred in the system due to the small absolute zeta potential. When the SE was in the range of 15-20, the system formed a stable nanoscale suspension, the average particle size and zeta potential were 191 nm and -20 mV, respectively. The physicochemical properties of the complexes were investigated including the colloidal properties, spectroscopy and interactions analysis, viscosity, contact angle, and antimicrobial activities against Escherichia coli, Staphylococcus aureus, and Penicillium expansum. Finally, the in vivo application on citrus demonstrated that the nanoscale PL/SPI electrostatic complex (SE = 20) as functional coatings has both barrier and antimicrobial activities. The study provides a novel application strategy for PL and nanoscale electrostatic complexes as postharvest coatings.
Topics: Polylysine; Soybean Proteins; Edible Films; Static Electricity; Citrus; Anti-Infective Agents; Escherichia coli
PubMed: 37652339
DOI: 10.1016/j.ijbiomac.2023.126616 -
Acta Biomaterialia Mar 2021Macrophage polarization is one of the main factors contributing to the proinflammatory milieu of transplanted islets. It causes significant islet loss. Bilirubin...
Macrophage polarization is one of the main factors contributing to the proinflammatory milieu of transplanted islets. It causes significant islet loss. Bilirubin exhibits protective effects during the islet transplantation process, but the mode of delivering drugs along with the islet graft has not yet been developed. In addition, it remains unclear whether bilirubin or its derivatives can modulate macrophage polarization during islet transplantation. Therefore, this study aimed to develop an ε-polylysine-bilirubin conjugate (PLL-BR) to encapsulate the islets for protection and to explore its macrophage modulation activities. In in vitro studies, the PLL-BR was shown to tightly adhere to the islet surface. It also exhibited enhanced cytoprotective effects against oxidative and inflammatory conditions by promoting M2-type macrophage polarization. In in vivo studies, the PLL-BR-protected islets successfully prolonged the euglycemia period in diabetic mice and accelerated the blood glucose clearance rate by maintaining the insulin secretion function. Compared to the untreated islets, the PLL-BR-encapsulated islets induced anti-inflammatory responses that were characterized by elevated levels of M2 macrophage markers and local vascularization. In conclusion, PLL-BR can be used as a tool for reprograming macrophage polarization while providing a more efficient immune protection for transplanted islets. STATEMENT OF SIGNIFICANCE: Macrophage polarization is one main factor that caused significant loss of transplanted islets. Bilirubin possesses protective effects toward pancreatic islet, but how to deliver the drug along with the islet graft has not yet been harnessed. More importantly, whether bilirubin or its derivatives could modulate macrophage polarization during the host rejections has also not been answered. In this study, we developed an ε-polylysine-bilirubin conjugate (PLL-BR) to encapsulate the islets and explore its role in macrophage modulation activities. PLL-BR could attach to the surface of islets and exerted high oxidation resistance and anti-inflammatory effect. For the first time, we demonstrate that bilirubin and its derivatives effectively promoted the M2-type macrophage polarization, and optimize the immune microenvironment for islets survival and function.
Topics: Animals; Bilirubin; Diabetes Mellitus, Experimental; Islets of Langerhans; Islets of Langerhans Transplantation; Macrophages; Mice; Polylysine
PubMed: 33387663
DOI: 10.1016/j.actbio.2020.12.047 -
Food Chemistry Nov 2023The high water-soluble films are commonly used in food coating and food encapsulation. In this study, the effect of Aloe vera gel (AV) and ε-polylysine (ε-PL) on the...
The high water-soluble films are commonly used in food coating and food encapsulation. In this study, the effect of Aloe vera gel (AV) and ε-polylysine (ε-PL) on the comprehensive properties of films based on guar gum (GG) were investigated. When GG to AV was 8:2, the GG:AV:ε-PL composite films (water solubility = 68.50%) had an 82.42% higher water solubility than pure guar gum (PGG) films (water solubility = 37.55%). Compared with PGG films, the composite films more transparent, better thermal stability and elongation at break. X-ray diffraction and SEM analysis showed the composite films were amorphous structures and the AV and ε-PL did not change the structure of PGG. FITR analysis confirmed the formation of hydrogen bonds within the composite films. Antibacterial properties showed the composite films had a good antibacterial effect against Escherichia coli and Staphylococcus aureus. Therefore, the composite films can be a new option of high water-soluble antibacterial food packaging materials.
Topics: Polylysine; Anti-Bacterial Agents; Escherichia coli; Water; Aloe
PubMed: 37385057
DOI: 10.1016/j.foodchem.2023.136686 -
Nanomedicine (London, England) 2015Since its discovery almost three decades ago, HIV-1 has grown into the most aggressive pandemic of modern time. Following the implementation of combination... (Review)
Review
Since its discovery almost three decades ago, HIV-1 has grown into the most aggressive pandemic of modern time. Following the implementation of combination antiretroviral therapy, the pathological outcome of HIV infection has substantially improved. However, combination antiretroviral therapy is limited by several factors including, long-term toxicity, serious side effects and complex dosing regimens, and so on. In this regard, researchers have directed their attention toward enhancing current treatment strategies and/or developing alternative HIV-1 therapeutics. In recent years, this attention has fixated on nanomedicine-based anti-HIV therapeutics (HIV-1 nanotherapeutics). In the present study, we have reviewed several HIV-1 nanotherapeutics that have shown success at the preclinical level and/or Phase I/II clinical trials. We also discuss the possible benefits of these nanomedicine-based approaches and their future outlook.
Topics: Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Clinical Trials as Topic; Dendrimers; HIV Infections; HIV-1; Humans; Nanomedicine; Nanostructures; Polylysine
PubMed: 26400459
DOI: 10.2217/nnm.15.160 -
International Journal of Food... Feb 2023Alicyclobacillus acidoterrestris has great influence on the quality of apple juice products. In this study, the antibacterial activity of five preservatives...
Alicyclobacillus acidoterrestris has great influence on the quality of apple juice products. In this study, the antibacterial activity of five preservatives (ε-polylysine, propylparaben, monocaprin, octyl gallate and heptylparaben) against A. acidoterrestris and its underlying mechanism were investigated. Results showed that these five preservatives all exerted antibacterial activity through a multiple bactericidal mechanism, and monocaprin and octyl gallate had the highest antibacterial activity, with the minimum inhibitory concentration (MIC) values of 22.5 and 6.25 mg/L, respectively. Five preservatives all changed the permeability of the cell membrane and destroyed the complete cell morphology, with the leakages of the intracellular electrolytes. Moreover, the treatment of ε-polylysine, propylparaben and monocaprin increased the leakage of intracellular protein; propylparaben and octyl gallate reduced the levels of cellular adenosine triphosphate. Also, monocaprin and octyl gallate may stimulate bacteria to release a large amount of reactive oxygen species, so that certain oxidative damage can kill the bacteria. Furthermore, monocaprin and octyl gallate could effectively inactivate the contamination of A. acidoterrestris in apple juices, with the slightly decrease of soluble sugars and organic acids, without significant adverse effects on total sugars and titratable acids. This research highlights the great promise of using monocaprin and octyl gallate as the safe multi-functionalized food additives for food preservations.
Topics: Malus; Polylysine; Alicyclobacillus; Anti-Bacterial Agents; Beverages; Spores, Bacterial
PubMed: 36473316
DOI: 10.1016/j.ijfoodmicro.2022.110039 -
Biophysical Chemistry Nov 2020Thylakoid membranes of photosynthetic plant chloroplasts are involved in a wide range of energy producing pathways. Their stacking can be employed in order to provide...
Thylakoid membranes of photosynthetic plant chloroplasts are involved in a wide range of energy producing pathways. Their stacking can be employed in order to provide increased surface area for biocatalytic purposes. Here we probe the aggregate formation of higher plants' thylakoids using low-molecular poly-l-lysine as an electrostatic polymer linker in low ionic strength media. Microelectrophoresis, actinic light scattering, millisecond-delayed fluorescence and free radical production of thylakoid membranes are measured and analyzed in the presence of the cationic polypeptide to track its influence on the surface electrical properties, the electron-transport processes and the proton gradient accumulation across membranes. Enhanced proton gradient in polylysine-treated thylakoids is obtained upon illumination due to alterations of the proton intake across the membrane resulting from the non-specific electrostatic interactions of the cationic polypeptide with thylakoids. We report lower rates of lipid peroxidation in polylysine-treated thylakoids measured both in the dark and under illumination in salt-free medium. The gained insight on the effect of polycations on photosynthetic membranes may be used in future developments of thylakoid-based approaches for energy transfer applications.
Topics: Electron Transport; Plant Leaves; Polylysine; Protons; Spinacia oleracea; Thylakoids
PubMed: 32771805
DOI: 10.1016/j.bpc.2020.106440