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Angewandte Chemie (International Ed. in... Sep 2019In nature, dynamic processes are ubiquitous and often characterized by adaptive, transient behavior. Herein, we present the development of a transient bowl-shaped... (Review)
Review
In nature, dynamic processes are ubiquitous and often characterized by adaptive, transient behavior. Herein, we present the development of a transient bowl-shaped nanoreactor system, or stomatocyte, the properties of which are mediated by molecular interactions. In a stepwise fashion, we couple motility to a dynamic process, which is maintained by transient events; namely, binding and unbinding of adenosine triphosphate (ATP). The surface of the nanosystem is decorated with polylysine (PLL), and regulation is achieved by addition of ATP. The dynamic interaction between PLL and ATP leads to an increase in the hydrophobicity of the PLL-ATP complex and subsequently to a collapse of the polymer; this causes a narrowing of the opening of the stomatocytes. The presence of the apyrase, which hydrolyzes ATP, leads to a decrease of the ATP concentration, decomplexation of PLL, and reopening of the stomatocyte. The competition between ATP input and consumption gives rise to a transient state that is controlled by the out-of-equilibrium process.
Topics: Adenosine Triphosphate; Animals; Artificial Cells; Cell Shape; Erythrocytes; Humans; Hydrophobic and Hydrophilic Interactions; Nanostructures; Nanotechnology; Polylysine
PubMed: 31267638
DOI: 10.1002/anie.201906331 -
Molecules (Basel, Switzerland) Oct 2019The cellular transport process of DNA is hampered by cell membrane barriers, and hence, a delivery vehicle is essential for realizing the potential benefits of gene... (Review)
Review
The cellular transport process of DNA is hampered by cell membrane barriers, and hence, a delivery vehicle is essential for realizing the potential benefits of gene therapy to combat a variety of genetic diseases. Virus-based vehicles are effective, although immunogenicity, toxicity and cancer formation are among the major limitations of this approach. Cationic polymers, such as polyethyleneimine are capable of condensing DNA to nanoparticles and facilitate gene delivery. Lack of biodegradation of polymeric gene delivery vehicles poses significant toxicity because of the accumulation of polymers in the tissue. Many attempts have been made to develop biodegradable polymers for gene delivery by modifying existing polymers and/or using natural biodegradable polymers. This review summarizes mechanistic aspects of gene delivery and the development of biodegradable polymers for gene delivery.
Topics: Animals; Biological Transport; Chitosan; Dextrans; Endosomes; Gene Transfer Techniques; Genetic Therapy; Glucans; Humans; Hyaluronic Acid; Hydrolysis; Lysosomes; Nanoparticles; Polyethyleneimine; Polylysine
PubMed: 31627389
DOI: 10.3390/molecules24203744 -
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 -
Journal of Dairy Science May 2022ε-Polylysine (ε-PL) is a natural preservative of antimicrobial peptides with broad spectrum and high antibacterial properties. The electrostatic complex delivery...
ε-Polylysine (ε-PL) is a natural preservative of antimicrobial peptides with broad spectrum and high antibacterial properties. The electrostatic complex delivery system formed by ε-PL and whey protein can be used to maintain the stability of ε-PL and solve the problem of limited application of protein-based food. This work aimed to study the interaction between ε-PL and whey protein by multiple characterization methods. The spectroscopy results showed static quenching type and new stretching of C=O for ε-PL-whey protein complexes. Microstructure studies showed that the combination of ε-PL and whey protein made the structure of the complexes become rough and dense. The interaction between ε-PL and whey protein could improve the stability of the complexes system during storage. Additionally, the interaction affected critical gel temperatures and gel texture properties of complexes with change of whey protein concentration, mass ratio of ε-PL to whey protein, pH value in alkaline solutions, and ion concentration. Overall, this study confirmed the interaction between ε-PL and whey protein, and it will provide a reference for the application of ε-PL in protein food matrix.
Topics: Animals; Anti-Bacterial Agents; Polylysine; Rheology; Static Electricity; Whey Proteins
PubMed: 35282919
DOI: 10.3168/jds.2021-21219 -
The Journal of Clinical Investigation Feb 2022BACKGROUNDLong-term prognosis of WHO grade II low-grade gliomas (LGGs) is poor, with a high risk of recurrence and malignant transformation into high-grade gliomas.... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUNDLong-term prognosis of WHO grade II low-grade gliomas (LGGs) is poor, with a high risk of recurrence and malignant transformation into high-grade gliomas. Given the relatively intact immune system of patients with LGGs and the slow tumor growth rate, vaccines are an attractive treatment strategy.METHODSWe conducted a pilot study to evaluate the safety and immunological effects of vaccination with GBM6-AD, lysate of an allogeneic glioblastoma stem cell line, with poly-ICLC in patients with LGGs. Patients were randomized to receive the vaccines before surgery (arm 1) or not (arm 2) and all patients received adjuvant vaccines. Coprimary outcomes were to evaluate safety and immune response in the tumor.RESULTSA total of 17 eligible patients were enrolled - 9 in arm 1 and 8 in arm 2. This regimen was well tolerated with no regimen-limiting toxicity. Neoadjuvant vaccination induced upregulation of type-1 cytokines and chemokines and increased activated CD8+ T cells in peripheral blood. Single-cell RNA/T cell receptor sequencing detected CD8+ T cell clones that expanded with effector phenotype and migrated into the tumor microenvironment (TME) in response to neoadjuvant vaccination. Mass cytometric analyses detected increased tissue resident-like CD8+ T cells with effector memory phenotype in the TME after the neoadjuvant vaccination.CONCLUSIONThe regimen induced effector CD8+ T cell response in peripheral blood and enabled vaccine-reactive CD8+ T cells to migrate into the TME. Further refinements of the regimen may have to be integrated into future strategies.TRIAL REGISTRATIONClinicalTrials.gov NCT02549833.FUNDINGNIH (1R35NS105068, 1R21CA233856), Dabbiere Foundation, Parker Institute for Cancer Immunotherapy, and Daiichi Sankyo Foundation of Life Science.
Topics: Adult; Aged; CD8-Positive T-Lymphocytes; Cancer Vaccines; Carboxymethylcellulose Sodium; Female; Glioma; Humans; Male; Middle Aged; Neoadjuvant Therapy; Poly I-C; Polylysine; Tumor Microenvironment; Vaccination
PubMed: 34882581
DOI: 10.1172/JCI151239 -
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 -
Protein Science : a Publication of the... Jul 2021Biomolecular condensates assembled through liquid-liquid phase separation (LLPS) of proteins and RNAs are currently recognized to play an important role in cellular...
Biomolecular condensates assembled through liquid-liquid phase separation (LLPS) of proteins and RNAs are currently recognized to play an important role in cellular organization. Their assembly depends on the formation of a network of transient, multivalent interactions between flexible scaffold biomolecules. Understanding how protein and RNA sequences determine these interactions and ultimately regulate the phase separation is an open key challenge. Recent in vitro studies have revealed that arginine and lysine residues, which are enriched in most cellular condensates, have markedly distinct propensities to drive the LLPS of protein/RNA mixtures. Here, we employ explicit-solvent atomistic molecular dynamics simulations to shed light on the microscopic origin of this difference by investigating mixtures of polyU oligonucleotides with either polyR/polyK peptides. In agreement with experiments, our simulations indicate that arginine has a higher affinity for polyU than lysine both in highly diluted conditions and in concentrated solutions with a biomolecular density comparable to cellular condensate. The analysis of intermolecular contacts suggests that this differential behavior is due to the propensity of arginine side chains to simultaneously form a higher number of specific interactions with oligonucleotides, including hydrogen bonds and stacking interactions. Our results provide a molecular description of how the multivalency of the guanidinium group enables the coordination of multiple RNA groups by a single arginine residue, thus ultimately stabilizing protein/RNA condensates.
Topics: Peptides; Poly U; Polylysine; RNA
PubMed: 33982350
DOI: 10.1002/pro.4109 -
PloS One 2016This study developed light cured dental composites with added monocalcium phosphate monohydrate (MCPM), tristrontium phosphate (TSrP) and antimicrobial polylysine (PLS)....
PURPOSE
This study developed light cured dental composites with added monocalcium phosphate monohydrate (MCPM), tristrontium phosphate (TSrP) and antimicrobial polylysine (PLS). The aim was to produce composites that have enhanced water sorption induced expansion, can promote apatite precipitation and release polylysine.
MATERIALS AND METHODS
Experimental composite formulations consisted of light activated dimethacrylate monomers combined with 80 wt% powder. The powder phase contained a dental glass with and without PLS (2.5 wt%) and/or reactive phosphate fillers (15 wt% TSrP and 10 wt% MCPM). The commercial composite, Z250, was used as a control. Monomer conversion and calculated polymerization shrinkage were assessed using FTIR. Subsequent mass or volume changes in water versus simulated body fluid (SBF) were quantified using gravimetric studies. These were used, along with Raman and SEM, to assess apatite precipitation on the composite surface. PLS release was determined using UV spectroscopy. Furthermore, biaxial flexural strengths after 24 hours of SBF immersion were obtained.
RESULTS
Monomer conversion of the composites decreased upon the addition of phosphate fillers (from 76 to 64%) but was always higher than that of Z250 (54%). Phosphate addition increased water sorption induced expansion from 2 to 4% helping to balance the calculated polymerization shrinkage of ~ 3.4%. Phosphate addition promoted apatite precipitation from SBF. Polylysine increased the apatite layer thickness from ~ 10 to 20 μm after 4 weeks. The novel composites showed a burst release of PLS (3.7%) followed by diffusion-controlled release irrespective of phosphate addition. PLS and phosphates decreased strength from 154 MPa on average by 17% and 18%, respectively. All formulations, however, had greater strength than the ISO 4049 requirement of > 80 MPa.
CONCLUSION
The addition of MCPM with TSrP promoted hygroscopic expansion, and apatite formation. These properties are expected to help compensate polymerization shrinkage and help remineralize demineralized dentin. Polylysine can be released from the composites at early time. This may kill residual bacteria.
Topics: Calcium Phosphates; Compressive Strength; Dental Materials; Elastic Modulus; Materials Testing; Microscopy, Electron, Scanning; Phosphates; Polylysine; Polymerization; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman; Strontium
PubMed: 27727330
DOI: 10.1371/journal.pone.0164653 -
Journal of Food Protection Jul 2023The purpose of the study was to investigate the mechanism of inactivation of Serratia liquefaciens by different treatments, namely corona discharge plasma (CDP),...
The purpose of the study was to investigate the mechanism of inactivation of Serratia liquefaciens by different treatments, namely corona discharge plasma (CDP), ε-polylysine (ε-PL), and corona discharge plasma combined with ε-polylysine (CDP plus ε-PL). The results showed that the combined treatment of CDP and ε-PL exhibited significant antibacterial effects. The total number of colonies of S. liquefaciens dropped by 0.49 log CFU/mL following 4 min of CDP treatment, 4MIC ε-PL treatment for 6 h alone decreased the amounts of colonies by 2.11 log CFU/mL, and 6 h of treatment with 4MIC ε-PL after the bacterium was treated with CDP could decrease the number of colonies by 6.77 log CFU/mL. Scanning electron microscopy images showed that the combined treatment of CDP and ε-PL caused the most serious damage to the cell morphology. Electrical conductivity, nucleic acid, and PI staining indicated that the combined treatment dramatically enhanced the permeability of the cell membrane. In addition, the combined treatment led to a significant decrease in SOD and POD enzyme activities in S. liquefaciens, which prevented energy metabolism. Finally, the determination of free and intracellular ε-PL concentrations confirmed that the treatment of CDP could cause the bacteria to bind more ε-PL and exert more significant bacterial inhibition. Therefore, CDP and ε-PL had a synergistic effect in the inhibition of S. liquefaciens.
Topics: Polylysine; Serratia liquefaciens; Anti-Bacterial Agents; Cell Membrane; Microscopy, Electron, Scanning
PubMed: 37295216
DOI: 10.1016/j.jfp.2023.100078 -
Journal of Investigative Medicine : the... Oct 2010In type 1 diabetes, the β-cells that secrete insulin have been destroyed such that daily exogenous insulin administration is required for the control of blood glucose...
INTRODUCTION
In type 1 diabetes, the β-cells that secrete insulin have been destroyed such that daily exogenous insulin administration is required for the control of blood glucose in individuals with the disease. After the development of reliable techniques for the isolation of islets from the human pancreas, islet transplantation has emerged as a therapeutic option, albeit for only a few selected patients largely because there are not enough islets for the millions of patients requiring the treatment, and there is also the need to use immunosuppressive drugs to prevent transplant rejection. In 1980, the concept of islet immunoisolation by microencapsulation was introduced as a technique to overcome these 2 major barriers to islet transplantation. Microencapsulation of islets and transplantation in the peritoneal cavity was then described as a bioartificial pancreas. However, it is difficult to retrieve encapsulated islets transplanted in the peritoneal cavity, thus making it difficult to meet all the criteria for a bioartificial pancreas. A new design of a bioartificial pancreas comprising islets co-encapsulated with angiogenic protein in permselective multilayer alginate-poly-L-ornithine-alginate microcapsules and transplanted in an omentum pouch is described in this paper.
MATERIALS AND METHODS
The multilayer alginate-poly-L-ornithine-alginate microcapsules are made with ultrapure alginate using poly-L-ornithine as a semipermeable membrane separating the 2 alginate layers. The inner alginate layer is used to encapsulate the islets, and the outer layer is used to encapsulate angiogenic protein, which would induce neovascularization around the graft within the omentum pouch.
RESULTS
In in vitro studies, we found that both the wild-type and the heparin-binding growth-associated molecule (HBGAM)-fibroblast growth factor-1 chimera can be encapsulated and released in a controlled and sustained manner from the outer alginate layer with a mean diameter in the range of 113 to 164 µm when 1.25% high guluronic acid alginate is used to formulate this outer layer.
DISCUSSION
We are currently performing in vivo experiments to determine the ability of angiogenic proteins released from this outer layer to induce neovascularization around the grafts in the omentum pouch. We will subsequently examine the effect of co-encapsulation of islets with angiogenic protein on blood glucose control in diabetic animals. It is hoped that addition of tissue engineering to encapsulated islet transplantation will result in long-term survival of the islets and their ability to control blood glucose in type 1 diabetes without the necessity to use risky immunosuppressive drugs to prevent transplant rejection.
Topics: Alginates; Animals; Diabetes Mellitus, Type 1; Humans; Islets of Langerhans Transplantation; Microspheres; Omentum; Pancreas, Artificial; Polylysine; Tissue Engineering
PubMed: 20683347
DOI: 10.231/JIM.0b013e3181ed3807