A methacrylate monomer having the phospholipid polar group, 2-methacryloyloxyethyl phosphorylcholine (MPC) was prepared by an improved method with good yield. MPC was copolymerized with n-butyl methacrylate (BMA). The polymer membranes were prepared from the poly(MPC-co-BMA) by a solution casting method. The membrane adsorbed water well and became a hydrogel structure even MPC mole fraction in the copolymer was 0.04. The water content of the hydrogel membrane increased with increase of MPC units and rise of temperature. These properties of the hydrogel membrane were attributed to the highly hydrophilic phospholipid polar group in the copolymer. Water soluble organic compounds and proteins whose molecular weights were below 10 4 permeated through the hydrogel membrane. However, the protein could not permeate when the molecular weight was higher than 10 5 • KEY WORDS Phospholipid Polymer; 2-Methacryloyloxyethyl Phosphorylcholine ; Membrane; Hydrogel; Water Content; Temperature Response; Permeation; Biomaterials Phospholipids are the main components of the biomembrane and interesting substances in biological and biomedical field. 1,2 Recently, the phospholipid membrane has been used as a drug carrier, sensor, separation membrane. 3 However, these phospholipid membranes were unstable physically and chemically, because the phospholipids constituting membranes do not bond covalently and have high mobility. To improve the mechanical strength of the phospholipid membranes, phospholipid molecules with polymerizable group were synthesized. 4 ,s (MPC) was synthesized and its copolymerization ability with methyl methacrylate was evaluated. 6 Moreover, the blood compatibility of the poly(MPC-co-MMA)s has been investigated. 7 We have developed new biocompatible materials based on the results that the surface of polymeric material showing good biocompatibility was covered with phospholipid molecules and formed biomembrane-like structure on the material. Therefore, a methacrylate having phosphorylcholine moiety, 2-methacryloyloxyethyl phosphorylcholine Polym.

Aldoses are one of the most important structural components of biomolecules, such as polysaccharides, nucleic acids, glycolipids and glycoproteins. In addition, numerous secondary metabolites in plants, such as terpenoids, steroids, and flavonoids, exist as glycosides, which conjugate with aldoses. Aldoses are optically active compounds, and confirmation of absolute configuration is required in natural product chemistry. Measurement of specific rotations of pure samples is the most reliable method, although this is impractical in many cases because only limited amounts of samples are available. Analysis using a column with a chiral stationary phase developed for the separation of enantiomers, or an HPLC system equipped with an optical rotation detector and a column specified for sugar analysis, can be applied 1,2) ; however, the latter method is not applicable to mixtures of Dand L-enantiomers. Identification of sugars with small optical rotation may be also difficult. Methods using capillary electrophoresis have also been developed, 3,4) but these methods require specialized equipment or columns that are unfamiliar to most organic chemistry laboratories. Some methods based on conversion of aldose enantiomers to diastereomeric derivatives through coupling to an optically active reagent have been developed 5,6) ; however, there are not many methods applicable to the widely used HPLC systems equipped with a UV detector and C 18 reversed-phase column. This paper describes a new method to discriminate between aldose enantiomers using a usual HPLC system. Results and DiscussionHara et al. developed an excellent method using gas chromatography, in which enantiomeric aldoses were converted to trimethylsilyl ethers of methyl 2-(polyhydroxyalkyl)-thiazolidine-4(R)-carboxylates. 7) In order to apply this method to HPLC analysis, we converted the thiazolizine derivatives to arylthiocarbamate (3, 4) by reaction with arylisothiocyanates.The reaction procedure is very simple: sugar samples, such as D-and L-glucoses (1, 2, respectively), are heated with L-cycteine methyl ester in pyridine at 60°C for 60 min, then arylisothiocyanate was added to the reaction mixture and further reacted at 60°C for 60 min. Then, the reaction mixture was directly analyzed by standard C 18 HPLC and detected by a UV detector (at 250 nm). When phenylisothiocyanate was used, the retention time (t R ) of the derivatives of D-and L-glucoses were 16.35 and 15.37 min, respectively. The derivatives of D-and L-glucoses (3, 4, respectively) were isolated and their structures were determined by 1 H-and 13 C-NMR spectra and FAB-MS analyses. Although the production of two diastereomers, which have an opposite configuration at the sugar C-1 position, was expected from each enantiomer, the 1 H-and 13 C-NMR spectra showed that one of the two possible diastereomers was produced preferably in the case of glucose.When the reaction mixture was stored at room temperature for a few days, the derivatives decomposed to give thiohydantoin compounds by elimination of metha...

Highlights d gRNA database, IFN-g treatment, and HLA staining facilitated HLA editing in iPSCs d Allele-specific knockout of HLA genes generates pseudohomozygous HLAs d Disrupting HLA-A/B, but retaining HLA-C, could evade CD8 + T and NK cell activities d Twelve lines of the HLA-C-retained cell would cover most of the HLA haplotypes

The hemocompatibility of a polymer containing a phospholipid polar group, poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate(BMA)), with human whole blood was evaluated. When human whole blood without an anticoagulant was contacted with polymers, the blood cell adhesion and aggregation on the polymer without the MPC moiety was extensive, and considerable fibrin deposition was observed. This phenomenon was suppressed with an increase in the polymer MPC composition. Thus, the MPC moiety in the copolymer plays an important role in the nonthrombogenic behavior of the copolymer. These results were also confirmed by the whole blood coagulation time on the polymer surface which was determined by Lee-White method. The adsorption of phospholipids and proteins from human plasma on poly(MPC-co-BMA) was investigated to clarify the mechanism of the nonthrombogenicity observed with the polymer. The amount of phospholipids was increased; whereas, adsorbed proteins were decreased with an increase in the MPC composition. From these results, we concluded that the phospholipids adsorbed on poly(MPC-co-BMA) play the most important role in the nonthrombogenicity of the MPC copolymer.

No abstract