Synthesis of novel liquid crystal compounds and their blood compatibility as anticoagulative materials

Abstract

The objective of this study was to synthesize new types of cholesteric liquid crystal compounds and study the anticoagulative properties of their composite membranes. Three kinds of cholesteric liquid crystal compounds were synthesized and characterized by infrared spectroscopy, differential scanning calorimetry and optical polarizing microscope. The polysiloxane, as a substrate, was blended with three liquid crystal compounds and was then used as membranes. The anticoagulative property of different polysiloxane liquid crystal composite membranes was identified by the blood compatibility tests. Three cholesteryl liquid crystals synthesized in this work contained hydrophilic soft chains and presented iridescent texture owned by cholesteric liquid crystals in the range of their liquid crystal state temperature, but only cholesteryl acryloyl oxytetraethylene glycol carbonate was in the liquid crystal state at body temperature. When liquid crystals were blended with polysiloxane to form polysiloxane/liquid crystal composite membranes, the haemocompatibility of these membranes could be improved to some extent. The blood compatibility of composite membranes whose hydrophilic property was the best was more excellent than that of other composite membranes, fewer platelets adhered and spread, and showed little distortion on the surface of materials.

Amphiphilic liquid-crystal block copolymer nanofibers via RAFT-mediated dispersion polymerization

“…After solvent evaporation and drying under vacuum, Chol-TEG-OH was obtained as a white waxy solid (35.9 g, yield: 58%). Synthesis of cholesteryl acryloyl tetraethylene glycol carbonate 35,40 (Chol-TEGA) Chol-TEG-OH was firstly dried by azeotropic distillation in toluene at 60 C under reduced pressure. Then acryloyl chloride (9.90 mL, 0.1013 mol) was added dropwise to a solution of Chol-TEG-OH (55.9 g, 0.0921 mol) and triethylamine (12.95 mL) in dry dichloromethane (250 mL) at 0 C under nitrogen.…”

“…5 We were thus interested in studying the effect of such monomers in RAFT-mediated radical polymerization in dispersed medium and in checking whether the same features could be obtained. Besides the benefit of a one-step process in terms of simplicity and easy scale-up, the choice of cholesteryl monomers presents other advantages such as biocompatibility 35 and the possibility to target stimuli-responsive nanoobjects imparted by their liquid-crystalline nature. 36,37 For this type of monomer, dispersion polymerization (in which the monomer is initially soluble in the medium) was preferred to aqueous emulsion polymerization because the monomer structure is not well-suited for efficient molecular diffusion in the water phase.…”

“…Moreover, up to now, dispersion polymerization led to better homogeneity in the particle morphology. 32,33 Original, mesogenic cholesteryl-based monomers (cholesteryl (meth)acryloyl tetraethylene glycol carbonate, Chol-TEG(M) A, 35 Scheme 1) were first designed, which were suitable for dispersion polymerization in an ethanol/water mixture in the presence of a random copolymer composed of either acrylic acid (AA) and poly(ethylene glycol) monomethyl ether acrylate (PEGA) (P(AA-co-PEGA)) or methacrylic acid (MAA) and poly (ethylene glycol) monomethyl ether methacrylate (PEGMA) (P(MAA-co-PEGMA)) as a macroRAFT agent. We were especially interested in determining whether the smectic order can be induced in the solvophobic domains of the formed block copolymer nanoobjects during the dispersion polymerization and whether the presence of a mesophase may positively impact the morphology and homogeneity of the nanoobjects.…”