Functional and rheological properties of proteins from frozen turkey breast meat with different ultimate pH at 24 h postmortem (pH(24)) have been studied. Sixteen breast fillets from Hybrid Tom turkeys were initially selected based on lightness (L*) values for each color group (pale, normal, and dark), with a total of ...

Today, liposomes are one of the most effective carriers systems employed in biological, pharmaceutical, medical and nutritional research. In order to optimize a liposomal formulation for the encapsulation, delivery and release of the entrapped material, it is necessary to study material passage through the lipidic and aqueous phases of the ...

In Parkinson's disease (PD), misfolded and aggregated α-synuclein protein accumulates in degenerating midbrain dopaminergic neurons. The amino acid alanine-76 in α-synuclein and phosphorylation at serine-87 and serine-129 are thought to regulate its aggregation and toxicity. However, their exact contributions to α-synuclein membrane association are less clear. We found that α-synuclein ...

Connexin-43 (Cx43) containing giant liposomes (GL) were prepared by a baculovirus expression-liposome fusion method. Recombinant budded viruses expressing Cx43 were prepared and then fused with GLs containing DOPG/DOPC at pH 4.5. Connexon formation on the GL membrane was observed by transmission electron microscope. Hydrophilic fluorescent dye transfers were observed through ...

Sensitive and selective biosensors for high-throughput screening are having an increasing impact in modern medical care. The establishment of robust protein biosensing platforms however remains challenging, especially when membrane proteins are involved. Although this type of proteins is of enormous relevance since they are considered in >60% of the pharmaceutical ...

Bipolar tetraether lipids (BTLs) are abundant in crenarchaeota, which thrive in both thermophilic and nonthermophilic environments, with wide-ranging growth temperatures (4-108°C). BTL liposomes can serve as membrane models to explore the role of BTLs in the thermal stability of the plasma membrane of crenarchaeota. In this study, we focus on ...

The combination of delivery systems like cationic liposomes and immunopotentiators such as Toll-like receptor (TLR) ligands is a promising approach for rational vaccine adjuvant design. The purpose of this study was to investigate how the incorporation of the poorly soluble TLR4 agonist monophosphoryl lipid A (MPL) into cationic liposomes based ...

Amphiphilic methacrylate co-polymers recently demonstrated antimicrobial activity. To understand their activity mechanism, we prepared three homologous methacrylate co-polymers with activity ranging from inactive (MMA) over specifically active (EMA) to non-specifically active (BMA) against bacteria and human erythrocytes. Fluorescent dye leakage assays were used to characterize their membrane-disrupting activity against liposomes ...

We report on an improved method to encapsulate proteins and other macromolecules inside surface-tethered liposomes to reduce or eliminate environmental interference for single-molecule investigations. These lipid vesicles are large enough for the molecule to experience free diffusion but sufficiently small so that the molecule appears effectively immobile under the fluorescence ...

Along with recent progress of nanotechnology, concern has risen about biological impacts of nanoparticles deriving from their interaction with cell membranes. Nanoparticles tend to adsorb proteins in vivo. Therefore, the physical properties of the conjugates to cell membranes must be investigated to elucidate and assess their properties. We examined whether ...

Cationic cell-penetrating peptides (CPPs) are a promising vehicle for the delivery of macromolecular drugs. Although many studies have indicated that CPPs enter cells by endocytosis, the mechanisms by which they cross endosomal membranes remain elusive. On the basis of experiments with liposomes, we propose that CPP escape into the cytosol ...

Phosphatidylethanolamine-based pH-sensitive liposomes of various compositions have been described as efficient systems for cytoplasmic delivery of molecules into cells. Incorporation of an amphiphile of appropriate structure is needed for the stabilization and performance of these vesicles. Among the wide variety of interesting activities displayed by Pseudomonas aeruginosa dirhamnolipids (diRL), is ...

The transfer kinetics of temoporfin, a classic photosensitizer, was analyzed by investigating the influence of total lipid content, temperature, as well as charge, acyl chain length, and saturation of the lipids in donor vesicles using a mini ion exchange column technique. The obtained results are consistent with an apparent first ...

Unilamellar liposomes composed of natural phospholipids provide a new promising class of protective agents for hypothermic storage, cryopreservation, or freeze-drying of red blood cells (RBCs). In this study, FTIR spectroscopy, MALDI-TOF MS, and colorimetric assays were used to investigate the effects of liposomes composed of a homologous series of linear ...

A new method for the screening of membrane-permeable compounds in traditional Chinese medicines (TCMs), using ultrafiltration and HPLC analysis, has been proposed. We hypothesized that exposure of a TCM extract to a liposome membrane, the concentration of membrane-permeable compounds in the solution should decrease. Using this approach, the permeability of ...

The potential of liposomes as a drug delivery system for use in the oral cavity has been investigated. Specifically targeting for the teeth, the in vitro adsorption of charged liposomal formulations to hydroxyapatite (HA), a common model substance for the dental enamel, has been conducted. The experiments were performed in ...

In this article, we present a novel, scalable liposomal preparation technique suitable for the entrapment of pharmaceutical agents into liposomes. This new method is based on the ethanol-injection technique and uses a membrane contactor module, specifically designed for colloidal system preparation. In order to investigate the process, the influence of ...

The microstructure of liposomes formed by the lipopolysaccharides (LPS) derived from Burkholderia cenocepacia ET-12 type strain LMG 16656, Burkholderia multivorans strain C1576 and Agrobacterium tumefaciens strain TT111 has been investigated by a combined experimental strategy, including dynamic light scattering (DLS), small-angle neutron scattering (SANS) and electron paramagnetic resonance (EPR). The ...

Self-assembled liposome gel from liposome and cholesterol-end capped polyethylene glycol, was systematically investigated by rheological method, especially in the aspect of its recovery ability upon either mechanical deformation or temperature change. The liposome gel was found to have rheological behavior similar to that of Maxwell model. The dynamic shear modulus ...

The colloidal stability of cationic 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) liposomes was measured in the presence of guar, carboxymethyl guar, hydroxypropyl guar (HPG), and in mixtures of HPG with boric acid. Carboxymethyl guar induced DOTAP aggregation, presumably by bridging flocculation. The interaction with HPG-borate, an anionic polyelectrolyte with labile charge groups, depended on ...

Dopamine delivery to the central nervous system (CNS) undergoes the permeability limitations of the blood-brain barrier (BBB). Condensation of dopamine with neutral amino acids could afford potential prodrugs able to interact with the BBB endogenous transporters and easily enter the brain. To improve the bioavailability of the dopamine prodrug, 2-amino-N-[2-(3,4-dihydroxy-phenyl)-ethyl]-3-phenyl-propionamide ...

Penetration of the liposome membranes formed in the gel phase from DPPC (DPPC liposomes) and in the liquid-crystalline phase from egg yolk lecithin (EYL liposomes) by the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) and 16 DOXYL (2-ethyl-2-(15-methoxy-oxopentadecyl)-4,4-dimethyl-3-oxazolidinyloxy) spin probes has been investigated. The penetration process was followed by 120 hours at 24(0)C, using the ...

Amphotericin B (AmB) is used in the treatment of fungal infections; however, its clinical use is limited by its toxic side effects. In this study, AmB-loaded cationic liposome gels were formulated with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), and cholesterol (CH) at a molar ratio of DOPE:DOTAP:CH = 4:5:1 in thermosensitive gel ...

Afri et al. reported in this journal (Free Radic. Biol. Med.32:605-618; 2002) that a direct relationship exists between the depth of alkanoylcoumarins 1 within the liposomal lipid bilayer and the rate at which they undergo superoxide-mediated saponification. These results were based on a correlation between the (13)C NMR chemical shift ...

In this work unilamellar liposomes doped with a novel non-ionic 5'-Uridine-head nucleolipid, Lauroyl Uridine (LU), were prepared and characterized for their ability to interact with the polynucleotide polyadenylic acid (poly-A). Vesicles, were made up of the cationic lipid DOTAP (1,2-Dioleoyl-3-Trimethylammonium-Propane), the zwitterionic lipid DOPE (1,2-Dioleoyl-sn-Glycero-3-Phosphoethanolamine), and the novel amphiphile Lauroyl ...

A novel polymer-modified thermosensitive liposome (pTSL) was developed for the delivery of Doxorubicin (DOX) for cancer therapy. Copolymers containing temperature-responsive N-isopropylacrylamide (NIPAAm) and pH-responsive propylacrylic acid (PAA) were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization, yielding copolymers with dual pH/temperature-dependent phase transition properties. When attached to liposomes, these copolymers ...

We previously reported that modification of GALA peptide on the surface of liposomes enhanced fusion with endosomal membrane, and cytoplasmic release of encapsulated macromolecules. We report herein that an additional coating of GALA-modified liposomes with 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer resulted in a two order of magnitude enhancement in the transfection ...

OBJECTIVE: We previously observed that T lymphocytes present in synovial fluid (SF) from patients with rheumatoid arthritis (RA) were sensitive to APO2L/TRAIL. In addition, there was a drastic decrease in the amount of bioactive APO2L/TRAIL associated with exosomes in SF from RA patients. This study was undertaken to evaluate the ...

An unsaturated hydrocarbon chain in phospholipid was reported to affect a phase transition and a fusogenic activity after mixing membranes, and consequently to achieve a high DNA transfection efficiency. We previously showed that a biosurfactant mannosylerythritol lipid-A (MEL-A) enhances the gene transfection efficiency of cationic liposomes. Here, we have studied ...

The effects of tricylic antidepressant clomipramine (CLO) on the membrane properties of saturated dimyristoyl phosphatidylcholine and dipalmitoyl phosphatidylcholine as well as on unsaturated egg yolk phosphatidylcholine liposomes were investigated by the electron paramagnetic resonance spin-labeling technique, in combination with the simulation of the spectra, taking into account that the membrane ...

Phospholipid vesicles have attracted considerable interest as a platform for a variety of biomolecular binding assays, especially in the area of membrane protein sensing. The development of liposome-based biosensors widely relies on the availability of simple and efficient protocols for their surface immobilization. We present a novel approach toward the ...

Proteoliposomes were directly prepared by synthesizing membrane proteins with the use of minimal protein synthesis factors isolated from Escherichia coli (the PURE system) in the presence of liposomes. Connexin-43 (Cx43), which is a water-insoluble integral membrane protein that forms a hexameric complex in membranes, was cotranslationally integrated with an essentially ...

Lipid-based drug delivery systems show great potential for enhancing oral bioavailability but have not been broadly applied, largely due to lack of general formulation guidance. In the previous studies, three different formulations including anionic SLNs, cationic SLNs, and liposomes were investigated and significantly enhanced the oral bioavailability of N3-o-toluyl-fluorouracil (TFu) ...

Recently, we showed that incorporation of poly[2-(2-ethoxy)ethoxyethyl vinyl ether (EOEOVE)], which exhibits a lower critical solution temperature around 40 degrees C, provides temperature-sensitive properties to stable liposomes. In this study, we applied this thermosensitive polymer for preparation of temperature-sensitive liposomes for tumor-specific chemotherapy with doxorubicin (DOX). We prepared liposomes consisting ...

The effect of melatonin was evaluated on three phosphatidylcholine-based membrane models. Changes in liposome dynamics were monitored by fluorescence, following the response of the probe merocyanine-540, as well as by differential scanning calorimetry (DSC). Langmuir monolayers were investigated using molecular area measurements, as well as by Brewster angle microscopy (BAM). ...

Membrane-modification effects, induced by ultraviolet (UV) irradiation in diacetylenic liposomes, were analyzed upon contact with cells, biological membranes, and proteins. Liposomes formulated with mixtures of unsaturated 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine and saturated 1,2-dimyristoyl-sn-glycero-3-phosphocholine, in a 1:1 molar ratio, were compared with those that were UV-irradiated and analyzed in several aspects. Membrane polymerization inherence ...

The main objective of this work was to increase the retarding effect of the acid dye Telon(®) Blue RR (C.I. Acid Blue 62; DyStar, Frankfurt, Germany) release on polyamide fibres dyeing by encapsulation of the dye in liposomes as an alternative to synthetic auxiliaries, in order to reduce effluent pollution. ...

The use of liposomes to encapsulate materials has received widespread attention for drug delivery, transfection, diagnostic reagent, and as immunoadjuvants. Phospholipid polymers form a new class of biomaterials with many potential applications in medicine and research. Of interest are polymeric phospholipids containing a diacetylene moiety along their acyl chain since ...

The addition of the channel-forming domain of colicin E1 to liposomes elicited the transmembrane diffusion (flip-flop) of lipids concomitant to the release of the fluorescent dye from liposomes. Good correlation was found between kinetic and concentration dependences of the two processes. Both the liposome leakage and the lipid flip-flop were ...

Alkylresorcinolic lipids isolated from cereal grains and their semi-synthetic myristoyl-sulphonyl derivatives (MSAR) were used to modify small long-circulating sphingomyelin-cholesterol liposomes. Those SM:Chol vesicles modified with 10-30 mol% resorcinolic lipids had stable size and low membrane permeability in vitro at 4 degrees C and 37 degrees C. Liposomes containing 30 mol% ...

The aim of this study was to evaluate whether temperature stress conditions affect the cellular uptake of liposomal doxorubicin, Doxil (DXL; Ortho Biotech, Raritan, New Jersey, USA), and liposomal daunorubicin, DaunoXome (DXM; Gilead Sciences, San Dimas, California, USA). Uptake of these cytotoxic compounds is essential for their pharmacological effect. Commercially ...

The influence of liposome composition, lamellarity, preparation method, and charge on the encapsulation efficiency, size, polydispersity, and surface charge of sumatriptan liposomes was studied. For this purpose, we studied multilamellar, unilamellar, and frozen and thawed liposomes. Positively or negatively charged liposomes were obtained using both phosphatidylcholine and cholesterol, in combination ...

The interactions between three liposomal formulations and Pseudomonas aeruginosa cells were evaluated by a lipid mixing assay and electron paramagnetic resonance (EPR) spectroscopy. The effect of the bacteria on the liposomal phase characteristics, the release of the liposomes' content, and the uptake rate of gentamicin by bacteria were monitored as ...

We have studied the loading of the opioid hydromorphone into liposomes using ammonium sulfate gradients. Unlike other drugs loaded with this technique, hydromorphone is freely soluble as the sulfate salt, and, consequently, does not precipitate in the liposomes after loading. We have derived a mathematical relationship that can predict the ...

The present study concerns the percutaneous absorption of naproxen (NPX), as model anti-inflammatory drug, included in liposome formulations constituted of different lipids: stratum corneum lipids (SCL) and phosphatidylcholine/cholesterol (PC/CHOL). Liposome dispersions were produced using two different methods: reverse-phase evaporation (REV) and thin layer evaporation (TLE). Morphology and dimensions of the ...

Amplified potentiometric transduction of DNA hybridization based on using liposome 'nanocarriers' loaded with the signaling ions is reported. The liposome-amplified potentiometric bioassay involved the duplex formation, followed by the capture of calcium-loaded liposomes, a surfactant-induced release and highly-sensitive measurements of the calcium signaling ions using a Ca(2+) ion-selective electrode (ISE). ...

High negative electric potential inside mitochondria provides a driving force for mitochondria-targeted delivery of cargo molecules linked to hydrophobic penetrating cations. This principle is utilized in construction of mitochondria-targeted antioxidants (MTA) carrying quinone moieties which produce a number of health benefitting effects by protecting cells and organisms from oxidative stress. ...

In this article, a novel delivery system for the anticancer drug, arsenic trioxide (ATO), is characterized. The release of ATO from DPPC liposomes with MPPC lysolipid incorporated into the bilayer was measured. Upon heating the liposomes to 37°C, there was a 15-25% release over 24 hours. The ATO release from ...

10-(Octyloxy) decyl-2-(trimethylammonium) ethyl phosphate (ODPC) is an alkylphospholipid that can interact with cell membranes because of its amphiphilic character. We describe here the interaction of ODPC with liposomes and its toxicity to leukemic cells with an ED-50 of 5.4, 5.6 and 2.9 microM for 72 h of treatment for inhibition ...

The aim of this work was to evaluate the ability of Transcutol (Trc) to produce elastic vesicles with soy lecithin (SL) and study the influence of the obtained vesicles on in vitro (trans)dermal delivery of minoxidil. To this purpose, so-called penetration enhancer-containing vesicles (PEVs) were prepared using Trc aqueous solutions ...