Phospholipid polymers acid

Biochemical tests are usually performed after pure cultures have been obtained. The standard indole, methyl red, Voges-Proskauer, citrate, and litmus milk tests may be used to show important physiological characteristics. To study the functional diversity of bacteria, the utilization of carbohydrates, amines, amides, carboxylic acids, amino acids, polymers, and other carbon and nitrogen sources can be tested.28 Dilution-based most-probable number (MPN) techniques with phospholipid fatty acids as biomarkers have been employed for studying different bacterial species in lakes.40 The patterns of antibiotic resistance in bacteria isolated from natural waters have been useful for identifying sources of water pollution.34... 

Similarly to the phospholipid polymers, the MPC polymers show excellent biocompatibility and blood compatibility [43—48]. These properties are based on the bioinert character of the MPC polymers, i.e., inhibition of specific interaction with biomolecules [49, 50]. Recently, the MPC polymers have been applied to various medical and pharmaceutical applications [44-47, 51-55]. The crosslinked MPC polymers provide good hydrogels and they have been used in the manufacture of soft contact lenses. We have applied the MPC polymer hydrogel as a cell-encapsulation matrix due to its excellent cytocompatibility. At the same time, to prepare a spontaneously forming reversible hydrogel, we focused on the reversible covalent bonding formed between phenylboronic acid and polyol in an aqueous system. 

Watanabe J, Eriguchi T, Ishihara K (2002) Stereocomplex formation by enantiomeric poly (lactic acid) graft-type phospholipid polymers for tissue engineering. Biomacromolecules 3 1109-1114... 

Watanabe J, Ishihara K (2005) Cell engineering biointerface focusing on cytocompatibility using phospholipid polymer with an isomeric oligo(lactic acid) segment. Biomacromolecules 6 1797-1802... 

Konno T, Ishihara K (2007) Temporal and spatially controllable cell encapsulation using a water-soluble phospholipid polymer with phenylboronic acid moiety. Biomaterials 28 1770-1777... 

Other phosphorus-containing organic compounds found in soils and waters include phospholipids, nucleic acids (DNA and RNA) and their nucleotide residues (Newman and Tate, 1980 Condron et al., 1990), phosphorylated polymers of mannose produced by yeasts (Harrison, 1987), and tei-choic acids that form the cell walls of many Gram-positive bacteria (Zhang et al., 1998 ... 

Watanabe, J., Ishihara, K., 2003. Change in cell adhesion property on cytocompatible interface using phospholipid polymer grafted with poly(D,L-lactic acid) segment for tissue engineering. Sci. Technol. Adv. Mater. 4,539—544. 

In this study, we synthesized a new water-soluble phospholipid polymer containing a p-vinylphenylboronic acid unit, that is, poly[MPC-co- -BMA-co-/ -vinylphenylboronic acid (VPBA)](PMBV). Also, we reported the synthesis and characterization of the polymer, formation and properties of polymeric hydrogel with PVA, and behavior of fibroblast cells in the hydrogel. 

Rasiel, A. et al., Phospholipid Coated Poly(Lactic Acid) Microspheres for the Delivery of LHRH Analogues, Polymers for Advanced Technologies. 13, 127, 2002. 

Fig. 1.4. Examples of surfactants, phospholipids and polymers with covalently bound probes. 1 2-(9-anthroyloxy)stearic acid. 2 6-(9-anthroyloxy)stearic acid.

Seki and Tirrell [436] studied the pH-dependent complexation of poly(acrylic acid) derivatives with phospholipid vesicle membranes. These authors found that polyfacrylic acid), poly(methacrylic arid) and poly(ethacrylic acid) modify the properties of a phospholipid vesicle membrane. At or below a critical pH the polymers complex with the membrane, resulting in broadening of the melting transition. The value of the critical pH depends on the chemical structure and tacticity of the polymer and increases with polymer hydro-phobicity from approximately 4.6 for poly(acrylic acid) to approximately 8 for poly(ethacrylic acid). Subsequent photophysical and calorimetric experiments [437] and kinetic studies [398] support the hypothesis that these transitions are caused by pH dependent adsorption of hydrophobic polymeric carboxylic acids... 

Polymeric phospholipids based on dioctadecyldimethylammonium methacrylate were formed by photopolymerization to give polymer-encased vesicles which retained phase behavior. The polymerized vesicles were more stable than non-polymerized vesicles, and permeability experiments showed that vesicles polymerized above the phase transition temperature have lower permeability than the nonpolymerized ones [447-449]. Kono et al. [450,451] employed a polypeptide based on lysine, 2 aminoisobutyric acid and leucine as the sensitive polymer. In the latter reference the polypeptide adhered to the vesicular lipid bilayer membrane at high pH by assuming an amphiphilic helical conformation, while at low pH the structure was disturbed resulting in release of the encapsulated substances. 

Since the fatty acid chains in each lipid were 18 carbons and 16 carbons, respectively, it is reasonable that they could form a mixed lipid phase. Furthermore the bis-dienoyl substitution of 15 favors the formation of crosslinked polymer networks. Ohno et al. showed that the dienoyl group associated with the sn-1 chain could be polymerized by lipid soluble initiators, e.g. AIBN, whereas the dienoyl in the sn-2 chain was unaffected by AIBN generated radicals. Conversely, radicals from a water-soluble initiator, e.g. azo-bis(2-amidinopropane) dihydrochloride (AAPD), caused the polymerization of the sn-2 chain dienoyl group, but not the sn-1 chain. These data provide clear evidence for the hypothesis of Lopez et al. that the same reactive group located in similar positions in the sn-1 and sn-2 chains of polymerizable 1,2-diacyl phospholipids are positionally inequivalent [23]. 

Monolayers are best formed from water-insoluble molecules. This is expressed well by the title of Gaines s classic book Insoluble Monolayers at Liquid-Gas Interfaces [104]. Carboxylic acids (7-13 in Table 1, for example), sulfates, quaternary ammonium salts, alcohols, amides, and nitriles with carbon chains of 12 or longer meet this requirement well. Similarly, well-behaved monolayers have been formed from naturally occurring phospholipids (14-17 in Table 1, for example), as well as from their synthetic analogs (18,19 in Table 1, for example). More recently, polymerizable surfactants (1-4, 20, 21 in Table 1, for example) [55, 68, 72, 121], preformed polymers [68, 70, 72,122-127], liquid crystalline polymers [128], buckyballs [129, 130], gramicidin [131], and even silica beads [132] have been demonstrated to undergo monolayer formation on aqueous solutions. 

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