Surface-Active Ionic Liquids and Surface-Active Quaternary Ammonium Salts from Synthesis, Characterization to Antimicrobial Properties.

The present work provides new evidence of the ongoing potential of surface-active ionic liquids (SAILs) and surface-active quaternary ammonium salts (surface-active QASs). To achieve this, a series of compounds were synthesized with a yield of ≥85%, and their thermal analyses were studied. Additionally, antimicrobial activity against both human pathogenic and soil microorganisms was investigated.

Surface Functionalization of Poly(lactic acid) via Deposition of Hydroxyapatite Monolayers for Biomedical Applications.

The surface modification of poly(lactic acid) (PLA) using hydroxyapatite (HAP) particles via Langmuir-Blodgett (LB) and Langmuir-Schaefer (LS) approaches has been reported. The HAP monolayer was characterized at the air/water interface and deposited on three-dimensional (3D) printed poly(lactic acid). The deposition of HAP particles using the LS approach led to a larger surface coverage in comparison to the LB method, which produces a less uniform coating because of the aggregation of the particles.

The Biomimetic System of Oleanolic Acid and Oleic Acid at the Air-Water Interface-Interactions in Terms of Nanotechnology-Based Drug Delivery Systems.

Oleanolic acid (OLA) and oleic acid (OA) are ubiquitous in the plant kingdom, exhibiting a therapeutic effect on human health, and are components of novel pharmaceutical formulations. Since OLA has limited solubility, the utilization of nanotechnology-based drug delivery systems enhancing bioavailability is highly advantageous. We report on the interfacial behavior of the OLA:OA system at various molar ratios, using the Langmuir technique to assess the dependence of the molar composition on miscibility and rheological properties affecting film stability.

Towards understanding the binding affinity of lipid drug carriers to serum albumin.

In the past several years there has been a rapid rise in the use of lipid-based drug formulations. In the case of intravenous drug administration the interaction of lipid carrier with serum albumin is crucial for the distribution of the bioactive molecules in the bloodstream and reaching the target tissue. In this work, we have explored the interaction of serum albumin with three-component lipid monolayer build of palmitoyloleoylphosphatidylcholine (POPC), sphingomyelin (SM), and cholesterol (Chol).

Effect of 1-alkyl-1-methylpiperidinium bromides on lipids of fungal plasma membrane and lung surfactant.

This study aimed to investigate the potential of 1-alkyl-1-methylpiperidinium bromides as fungicides and evaluate their impact on the human respiratory system when spread in the atmosphere. We investigated the behavior of membrane lipids and model membranes in the presence of a series of amphiphilic 1-alkyl-1-methylpiperidinium bromides ([MePipC][Br]), differing in the alkyl chain length (n = 4 - 18). The experiments were performed with the Langmuir monolayer technique using 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and ergosterol (ERG)-the main components of lung surfactant and fungal plasma membrane, respectively and their mixtures with phospholipids and sterols.

Physicochemical Characterization of Oleanolic Acid-Human Serum Albumin Complexes for Pharmaceutical and Biosensing Applications.

Among numerous compounds found in marine organisms, triterpenes have attracted considerable research interest due to a beneficial impact on health including anti-inflammatory, antitumor, antiviral, and antioxidation effects. Specifically, new functionalities of oleanolic acid (OLA) have been revealed recently, indicating possible applications in nutrition and pharmaceuticals. However, this bioactive material has limited value due to low water solubility and stability.

Thermodynamic, viscoelastic and electrical properties of lipid membranes in the presence of astaxanthin.

Among numerous compounds found in marine organisms, astaxathin has received considerable research interest due to beneficial impact on health such as anti-inflammatory, antioxidant and neuroprotective activity. Recently new functionalities of this xanthophyll have been revealed indicating important applications in nutrition and pharmacy. However, astaxanthin, as the bioactive, has limited value without a protecting carrier that provides controlled release in a human body.

Lipid-Protein Interactions in Langmuir Monolayers under Dynamically Varied Conditions.

In the Langmuir monolayer technique, a single layer of molecules is formed on a water subphase. This approach was used to mimic the antitumoricidal lipid-protein complex of oleic acid and bovine α-lactalbumin called the BAMLET complex. Our previous studies have shown that at the interface, the BAMLET complex is stabilized by the hydrophobic forces supported by the hydrogen bonds.

Langmuir-Blodgett films of membrane lipid in the presence of hybrid silsesquioxane, a promising component of biomaterials.

Functionalized polyhedral oligomeric silsesquioxanes (POSS) derivatives have great potential in biomedical applications such as tissue engineering, drug delivery, biosensors, dental composites and biomedical devices. Having the above in mind, in this paper, the study of the surface characteristics of binary Langmuir-Blodgett films consisting of an open cage silsesquioxane POSS-poly (ethylene glycol) (POSS-PEG) and 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE), as a representative of phospholipid was conducted based on contact angle measurements of three liquids. The measured values of the contact angle (with water, formamide and diiodomethane as the wetting liquids) allowed to calculate surface free energy of the films from van Oss et al.

Temperature, pH, and Molecular Packing Effects on the Penetration of Oleic Acid Monolayer by α-Lactalbumin.

Recently, we reported on the interfacial behavior of mixed oleic acid (OA)-α-lactalbumin monolayer and its relevance in the formation of tumoricidal HAMLET (human α-lactalbumin made lethal to tumor cells)-like complex. This complex is probably formed in the gastrointestinal tract, but it has not been proved so far. The molecular base and the underlying physicochemical forces leading to such complexation remain to be known as well.

Morphology, compressibility and viscoelasticity of the mixed lipid monolayers in the presence of β-carotene.

The aim of the present study was to investigate the interfacial behaviour of model biomembranes in the presence of β-carotene (βC). The Langmuir monolayer technique was used to form the mixed lipid film at the air/water interface. Using the surface pressure-area isotherms, the surface potential-area curves and the Brewster angle microscopy the nature of interactions between carotenoid and lipid components of the monolayers was investigated.

Synthesis of an Open-Cage Structure POSS Containing Various Functional Groups and Their Effect on the Formation and Properties of Langmuir Monolayers.

Recently, silsesquioxanes have been recognized as a new group of film-forming materials. This study has been aimed at determining the effect of the kind of functional groups present in two different open-cage structure POSS molecules on the possibility of the formation of Langmuir monolayers and their properties. To achieve this goal, two new POSS derivatives (of open-cage structures) containing polyether and fluoroalkyl functional groups have been synthesized on the basis of a hydrosilylation process.

Interaction of polyhedral oligomeric silsesquioxane containing epoxycyclohexyl groups with cholesterol at the air/water interface.

Binary mixtures of cholesterol and fully-condensed octakis[{2-(3,4-epoxycyclohexyl) etyl}dimethyl-silyloxy]octasilsesquioxane (OE-POSS) were characterized using Langmuir trough for obtaining surface pressure-area isotherms. The most characteristic feature of the mixed films is the presence of two collapse points on the isotherms. The first one is attributed to the collapse of less stable OE-POSS and it occurs at similar surface pressures for all compositions, while the second one corresponds to cholesterol collapse.

Dynamics of adsorption in micellar and non micellar solutions of derivatives of lysosomotropic substances.

Dynamics of adsorption in micellar and non micellar solutions of derivatives of lysosomotropic substances was studied. The following compounds were considered in our research work: alkyl N,N-dimethyl-alaninates methobromides (DMALM-n), alkyl N,N-dimethylglycinates methobromides (DMGM-n), fatty acids N,N-dimethylaminoethylesters methobromides (DMM-n), fatty acids N,N-dimethylaminopropylesters methobromides (DMPM-n), fatty acids 1-dimethylamino-2-propyl methobromides (DMP(2)M-n), and derivatives of aminoesters with double alkyl chains (M(2)M-n). The examined compounds show interesting biological properties which can be useful, especially in medicine.

Surface properties of the derivatives of lysosomotropic substances against other quaternary ammonium salts.

Equilibrium adsorption at the air/water interface of cationic surfactants belonging in the group of quaternary ammonium bromides was studied. Quaternary ammonium salts, derivatives of lysosomotropic substances with different alkyl chain numbers and hydrophobicities were investigated. Surface properties of considered compounds, were examined and presented against other quaternary ammonium bromides of different chemical structure and with different number of alkyl chains in the molecule.

The effect of molecular structure on the surface properties of selected quaternary ammonium salts.

Equilibrium and dynamics of adsorption at the air/water interface of cationic surfactants belonging in the group of quaternary ammonium bromides was studied. Static surface tension of aqueous surfactants' solutions was measured in a wide range of surfactant concentrations using du Noüy ring method. Quaternary ammonium salts with different alkyl chain numbers and hydrophobicities were investigated.