Search results for "POLYLYSINE"

Shelf life extension of mozzarella cheese contaminated with Penicillium spp. using the antifungal compound ɛ-polylysine.

2019

Molds are one of the most important spoilage organisms on cheese which can lead to economic loss as well as raising public health concerns due to the production of mycotoxins. This study investigates the use of ɛ-polylysine as natural antimicrobial to inhibit fungal growth. The minimal inhibitory concentrations and minimal fungicidal concentrations of ɛ-polylysine were determined against Penicillium roqueforti, Penicillium nordicum, and Penicillium solitum. Then, polylysine was tested as surface antimicrobial for the preservation of mozzarella slice cheese inoculated with these Penicillium spp. and stored in plastic trays during 25 days. The minimal inhibitory concentrations calculated for…

Bifunctional poly(acrylamide) hydrogels through orthogonal coupling chemistries

2019

Biomaterials for cell culture allowing simple and quantitative presentation of instructive cues enable rationalization of the interplay between cells and their surrounding microenvironment. Poly(acrylamide) (PAAm) hydrogels are popular 2D-model substrates for this purpose. However, quantitative and reproducible biofunctionalization of PAAm hydrogels with multiple ligands in a trustable, controlled, and independent fashion is not trivial. Here, we describe a method for bifunctional modification of PAAm hydrogels with thiol- and amine- containing biomolecules with controlled densities in an independent, orthogonal manner. We developed copolymer networks of AAm with 9% acrylic acid and 2% N-(4…

Bifunctional Hydrogels Containing the Laminin Motif IKVAV Promote Neurogenesis

2017

Summary Engineering of biomaterials with specific biological properties has gained momentum as a means to control stem cell behavior. Here, we address the effect of bifunctionalized hydrogels comprising polylysine (PL) and a 19-mer peptide containing the laminin motif IKVAV (IKVAV) on embryonic and adult neuronal progenitor cells under different stiffness regimes. Neuronal differentiation of embryonic and adult neural progenitors was accelerated by adjusting the gel stiffness to 2 kPa and 20 kPa, respectively. While gels containing IKVAV or PL alone failed to support long-term cell adhesion, in bifunctional gels, IKVAV synergized with PL to promote differentiation and formation of focal adh…

Antifungal and antimycotoxigenic activity of polylysine biofilms

2016

Dynamic evaluation of aggregation and agglutination of red blood cells.

1984

Viscoelastic evaluation of aggregation and agglutination of red blood cells was attempted. A concentric double cylinder viscoelastometer was used for determining the dynamic rigidity modulus and loss modulus of blood sample. The dynamic rigidity modulus of horse blood were measured over a wide range of hematocrit. The relation between the viscoelastic behavior and the erythrocyte sedimentation was examined. The change in the amount of surface charge of enzyme treated red blood cells was qualitatively estimated from the measurements of dynamic viscoelasticity of red blood cells suspension with added poly-L-lysine. The dynamic rigidity modulus of red blood cells agglutinated by adding lectin …

Differential specificity of substrate-attached lectins stimulating spreading of GH3-cells under serum-free, hormone-supplemented culture conditions

1982

Most mammalian cells are capable of growth in culture only when they are supplied with an appropriate substrate to which they can adhere and spread. To prepare suitable substrates different lectins were attached onto polystyrene tissue-culture dishes after coating with polylysine. GH3-cells (a pituitary-tumor-cell line) were seeded into the culture dishes containing serum-free, hormone-supplemented medium. When succinylated Concanavalin A (s-Con A), which binds specifically to mannose residues, is attached to the surface an extraordinary spreading of GH3-cells is induced within 15 to 20 min after seeding. Other lectins with a different sugar-binding specificity are less effective in inducin…

Enhanced Efficacy and Broadening of Antibacterial Action of Drugs via the Use of Capped Mesoporous Nanoparticles

2013

[EN] A novel nanodevice consisting of mesoporous nanoparticles loaded with vancomycin and capped with epsilon-poly-L-lysine (epsilon-PL) was prepared and its interaction with different Gram-negative bacteria studied. A remarkable improvement in the efficacy of the antimicrobial drug epsilon-PL and a broadening of the antimicrobial spectrum of vancomycin is demonstrated.

Macromolecular Prodrugs Based on Synthetic Polyaminoacids: Drug Delivery and Drug Targeting in Antitumor Therapy

2011

In the last twenty years a depth study on potential pharmaceutical applications of synthetic polymers at proteinlike structure as carrier for macromolecular prodrug production has been performed in academia and in industry. In particular α,β-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA), α,β-polyaspartylhydrazide (PAHy), poly(glutamic acid) (PGA), poly(aspartic acid) (PAA) and polylysine (PLL) have been extensively studied in this field. In the present review, the use of PHEA, PAHy, PGA as starting materials to prepare macromolecular prodrugs is reported and drug delivery and targeting aspects have been considered.

Electrochemical Characterization of Polyelectrolyte/Gold Nanoparticle Multilayers Self-Assembled on Gold Electrodes

2006

Polyelectrolyte/gold nanoparticle multilayers composed of poly(l-lysine) (pLys) and mercaptosuccinic acid (MSA) stabilized gold nanoparticles (Au NPs) were built up using the electrostatic layer-by-layer self-assembly technique upon a gold electrode modified with a first layer of MSA. The assemblies were characterized using UV-vis absorption spectroscopy, cyclic and square-wave voltammetry, electrochemical impedance spectroscopy, and atomic force microscopy. Charge transport through the multilayer was studied experimentally as well as theoretically by using two different redox pairs [Fe(CN)(6)](3-/4-) and [Ru(NH(3))(6)](3+/2+). This paper reports a large sensitivity to the charge of the out…

Solid-state NMR investigation on the interactions between a synthetic montmorillonite and two homopolypeptides.

2006

Abstract Interactions of two homopolypeptides (polylysine and polyglutamic acid) with a synthetic montmorillonite were studied by 1H MAS, 1H–27Al HETCOR and 1H–13C CP-MAS NMR experiments. 1H–27Al HETCOR with 1H spin-diffusion NMR appears to be a powerful probe for the identification of the polypeptide fragments, which interact with the montmorillonite interlayer surfaces. In particular, selective interactions were observed between the polypeptide side-chains and the montmorillonite octahedral aluminum atoms. 1H–13C CP-MAS NMR experiments were used to assess the dynamics of the two polypeptides through the measurement of the t1/2 characteristic time of selected carbons. Results indicate that…