Poly[[µ-(3-amino-pyridine)-κ(2)N:N'-µ-chlorido-chlorido(N,N'-dimethyl-formamide-κO)nickel(II)] N,N'-dimethyl-formamide monosolvate].

The title compound, {[NiCl(2)(C(5)H(6)N(2))(C(3)H(7)NO)]·C(3)H(7)NO}(n), is a two-dimensional polymer in which the Ni(II) atom is coordinated by two N atoms from two 3-amino-pyridine ligands, one O atom from a dimethyl-formamide (DMF) group, one terminal Cl and two bridging Cl atoms in a distorted octa-hedral geometry. The Ni(II) atoms are bridged by the 3-amino-pyridine ligands [Ni⋯N = 6.7048 (3) Å] and Cl(-) atoms [Ni⋯N = 3.5698 (3) Å], forming (4,4) two-dimensional nets. The DMF solvent mol-ecule and the non-bridged Cl(-) ions participate in N-H⋯O and N-H⋯Cl hydrogen bonds with the amino groups.

catena-Poly[(µ-2-amino-1,3,4-thia-diazole-κN:N)di-µ-chlorido-cadmium].

In the title coordination polymer, [CdCl(2)(C(2)H(3)N(3)S)](n), the Cd(II) cation is coordinated by four Cl(-) anions and two N atoms from two trans 2-amino-1,3,4-thia-diazole (L) ligands in a distorted octa-hedral geometry. The L ligand and Cl(-) anions bridge adjacent Cd cations, forming a polymeric chain along the b axis; the separation between adjacent Cd cations is 3.619 (1) Å. In the crystal, the polymeric chains are inter-linking through N-H⋯Cl hydrogen bonds between the L ligands and Cl(-) anions.

Surface modification of poly(tetramethylene adipate-co-terephthalate) membrane via layer-by-layer assembly of chitosan and dextran sulfate polyelectrolyte multiplayer.

The improvement of hydrophilicity and hemocompatibility of poly(tetramethylene adipate-co-terephthalate) (PTAT) membrane was developed via polyelectrolyte multilayers (PEMs) immobilization. The polysaccharide PEMs included chitosan (CS, as a positive-charged and antibacterial agent) and dextran sulfate (DS, as a negative-charged and anti-adhesive agent) were successfully prepared using the aminolyzed PTAT membrane in a layer-by-layer (LBL) self-assembly manner. The obtained results showed that the contact angle of as-modified PTAT membranes reached to the steady value after four bilayers of coating, hence suggesting that the full coverage was achieved. It could be found that the PTAT-PEMs membranes with DS as the outmost layer could resist the platelet adhesion and human plasma fibrinogen (HPF) adsorption, thereby prolonging effectively the blood coagulation times. According to L929 fibroblast cell growth inhibition index, the as-prepared PTAT membranes exhibited non-cytotoxic. Overall results demonstrated that such an easy, valid and shape-independent processing should be potential for surface modification of PTAT membrane in the application of hemodialysis devices.

Cellular fusion and whitening effect of a chitosan derivative coated liposome.

In this study, a derivative of chitosan, N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC), was coated onto the liposomes made of cholesterol and 1,2-palmitoyl-sn-glycero-3-phosphatidylcholine (DPPC). These coated liposomes were loaded with kojic acid for skin whitening. The appearance of liposome was examined using transmission electron microscope (TEM), and the coating of HTCC to the liposome was confirmed by infrared spectroscopy. By labeling with Dil, the fusion of liposome with the cell membrane of L929 fibroblast and B16-F10 melanoma was improved by the coating of HTCC. Based on the results of Franz cell experiment, the penetration of kojic acid (KA) through skin was improved by using HTCC-coating liposomes. Furthermore, the cell proliferation of L929 was not affected by HTCC-coating liposomes, while that of B16-F10 was reduced slightly with the increase of the concentration of HTCC-loading liposome. The degree of skin whitening was determined based on the melanin content in B-16-F10 cells. The results showed that the level of melanin synthesis was lower when KA was delivered using HTCC-coating liposome instead of traditional liposome.

Antibacterial activity and cytocompatibility of chitosan-N-hydroxy-2,3-propyl-N methyl-N,N-diallylammonium methyl sulfate.

A water-soluble quaternary ammonium salt of chitosan, chitosan-N-hydroxy-2,3-propyl-N-methyl-N,N-diallylammonium methyl sulfate (MDAACS), was synthesized by reacting chitosan with methyl diallyl ammonium salt (MDAA). The results of water contact angle and swelling ratio showed that the membrane of MDAACS was more hydrophilic than chitosan. The antibacterial activities of MDAACS against Staphylococcus aureus and Klebsiella pneumoniae were evaluated with the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The results showed that the antibacterial activity of MDAACS was higher than that of chitosan. The cytocompatibility was evaluated in vitro with L929 fibroblast proliferation based on MTT colorimetric assay. The results showed that cell growth was much higher on MDAACS than on chitosan.