Pluronic P123/DMSO Lyotropic Liquid Crystal for Incorporating Bioactive Substances for Topical Application.

Lyotropic liquid crystals (LLCs) have attracted considerably growing interest in drug delivery applications over the last years. The structure of LLC matrices is complementary to cell membranes and provides an efficient, controlled, and selective release of drugs. In this work, a complex of experimental methods was used to characterize binary LLCs Pluronic P123/DMSO and triple LLC systems Pluronic P123/DMSO/Ibuprofen, which are interesting as transdermal drug delivery systems.

Concentration-dependent dielectric and electro-optical properties of composites based on nematic liquid crystals and CdS:Mn quantum dots.

Composites in a wide concentration range of 0-0.6 wt% based on a nematic liquid crystal mixture and CdS quantum dots doped with manganese ions (Mn 6%) are presented. The effect of the CdS:Mn quantum dots on the phase diagram and electronic structure of composites was studied using differential scanning calorimetry and fluorescence analysis.

Chitosan/Lactic Acid Systems: Liquid Crystalline Behavior, Rheological Properties, and Riboflavin Release In Vitro.

Chitosan or its derivatives exhibit lyotropic liquid crystalline mesophases under certain conditions due to its semi-rigid structures. This work describes the development of chitosan-based biocompatible systems that include new components: lactic acid and non-ionic surfactants. Polarized optical microscopy studies revealed that these systems are capable of forming gels or lyotropic liquid crystals (LLCs) in a certain range of chitosan and lactic acid concentrations.

Effect of Magnetic and Electric Field on the Orientation of Rare-Earth-Containing Nematics.

We report rare-earth-containing metallomesogens with newly synthesized ligands represented by the β-diketone 1-(4-(4-propylcyclohexyl)phenyl)octane-1,3-dione (CPD) and the Lewis base 5,5'-bis(heptadecyl)-2,2'-bipyridine (bpy). The stoichiometry of the complexes is [Ln(CPD)bpy], where Ln is a trivalent rare-earth ion (La, Sm, Eu, Gd, Tb, Dy, Ho, Tm, and Yb). Although the ligands themselves do not form any mesophase, the respective metal complexes produce nematic and smectic A phases.

Incorporating a Tetrapeptide into Lyotropic Direct Hexagonal Mesophase.

An approach to incorporate a bioactive hydrophobic substance, CHNO tetrapeptide (TP), into the structure of the hexagonal mesophases CEO/HO and CEO/La(III)/HO was proposed. Concentration and temperature ranges of mesophases in the CEO/HO/TP and CEO/La(III)/HO/TP systems were established. The analysis of the X-ray diffraction data revealed a change in the structural characteristics of mesophases in the presence of tetrapeptide.

Influence of Eu(III) Complexes Structural Anisotropy on Luminescence of Doped Conjugated Polymer Blends.

Europium(III) complexes that are the anisometric analogues of a well-known Eu(DBM)Phen (DBM = dibenzoylmethane; Phen = 1,10-phenanthroline) complex were synthesized. Quantum-chemical calculations of the excited states of new Eu(III) complexes and some conjugated polymers showed that poly(N-vinylcarbazole) provides the most efficient energy transfer in polymer films doped with synthesized Eu(III) complexes. These new composite films were prepared, and their luminescence properties were studied.

Influence of structural anisotropy on mesogenity of Eu(III) adducts and optical properties of vitrified films formed on their base.

A new series of europium adducts with the general formula Eu(CPDk3-CnH2n+1)3Phen, where CPDk3-CnH2n+1 denotes β-diketones and Phen is 1,10-phenanthroline, was synthesized. The obtained mesogenic complexes were heated to the temperatures of the isotropic liquid state and then cooled. The complexes having short CH3 and C2H5 substituents crystallized upon cooling, and the complexes with longer substituents from C3H7 to C6H13 underwent a glass transition with the formation of optically transparent amorphous films.