The cytotoxicity profile of three chitosan derivatives with different affinity to water was evaluated in vitro. The derivatives selected were carboxymethylated-chitosan （CMCH）, linoleic acid modifiedchitosan （LACH...The cytotoxicity profile of three chitosan derivatives with different affinity to water was evaluated in vitro. The derivatives selected were carboxymethylated-chitosan （CMCH）, linoleic acid modifiedchitosan （LACH） and deoxycholic acid modified-chitosan （DACH）, respectively, and the results of FTIR and NMR confirmed the successful modification. Cytotoxicity of these polymers was investigated via the red blood cell lysis assay and the MTT assay. The red blood cell lysis test showed that CH elicited a certain level of red blood cell toxicity, while CMCH, LACH and DACH all displayed low membrane damaging effects, with the hemolysis rates of 2.385%, 1.560% and 4.404%, respectively, which comes well within permissible limit （5%）. The MTT assay revealed that CH exhibited significant inhibitory effect on fibroblast proliferation at higher concentration, while its three derivatives showed no cytotoxicity. CMCH had stimulatory effects on fetal mouse fibroblast proliferation. Differences in cytotoxicity of CH and its derivatives may result from the specific chemical modifications leading to the alteration of molecular charge density and type of the cationic functionalities, structure and sequence, and conformational flexibility.展开更多
A penta-coordinated Cu(II) complex with 1,4-diazacycloheptane (DACH),[Cu(DACH)_2(H_2O)]Cl_2 (1), has been synthesized and characterized by X-ray diffraction, IR spectra,elemental analyses, thermal analyses, UV-Vis and...A penta-coordinated Cu(II) complex with 1,4-diazacycloheptane (DACH),[Cu(DACH)_2(H_2O)]Cl_2 (1), has been synthesized and characterized by X-ray diffraction, IR spectra,elemental analyses, thermal analyses, UV-Vis and ESR techniques. Complex 1 crystallizes inorthorhombic crystal system, Pbcn space group with a = 1.6075(4), b = 1.0539(3), c = 0.9195(3) nm, V= 1.5578(7) nm^3, M_r = 352.79, Z = 4, D_c = 1.487 g/cm^3, final R = 0.0451 and wR = 0.1294. Thestructure of 1 indicates that the central Cu(II) atom is penta-coordinated by four nitrogen atoms oftwo DACH moieties at the equatorial positions and a water molecule at the axis position. Thecoordination geometry of Cu(II) could be considered as an approximately ideal square-pyramidalenvironment. Both DACH rings arrange in cis-form and are predominantly in the boat-boat conformation(80%) with some disorder to the chair-chair conformation (20%). The Cl^- anions are hydrogen bondedwith the nitrogen donors of the DACH rings and the oxygen donor of the coordinated H_2O molecule toform a one-dimensional zigzag linear structure. The solution behaviors of 1 are also discussed indetail by Uv-vis and ESR technique.展开更多
基金the National Natural Science Foundation of China(No.30370344)
文摘The cytotoxicity profile of three chitosan derivatives with different affinity to water was evaluated in vitro. The derivatives selected were carboxymethylated-chitosan （CMCH）, linoleic acid modifiedchitosan （LACH） and deoxycholic acid modified-chitosan （DACH）, respectively, and the results of FTIR and NMR confirmed the successful modification. Cytotoxicity of these polymers was investigated via the red blood cell lysis assay and the MTT assay. The red blood cell lysis test showed that CH elicited a certain level of red blood cell toxicity, while CMCH, LACH and DACH all displayed low membrane damaging effects, with the hemolysis rates of 2.385%, 1.560% and 4.404%, respectively, which comes well within permissible limit （5%）. The MTT assay revealed that CH exhibited significant inhibitory effect on fibroblast proliferation at higher concentration, while its three derivatives showed no cytotoxicity. CMCH had stimulatory effects on fetal mouse fibroblast proliferation. Differences in cytotoxicity of CH and its derivatives may result from the specific chemical modifications leading to the alteration of molecular charge density and type of the cationic functionalities, structure and sequence, and conformational flexibility.
基金theNationalNaturalScienceFoundationofChina (No .2 99710 19)andtheTrans CenturyTalentsTrainingProgramFoundationfromtheStateEducationMinistryofChina
文摘A penta-coordinated Cu(II) complex with 1,4-diazacycloheptane (DACH),[Cu(DACH)_2(H_2O)]Cl_2 (1), has been synthesized and characterized by X-ray diffraction, IR spectra,elemental analyses, thermal analyses, UV-Vis and ESR techniques. Complex 1 crystallizes inorthorhombic crystal system, Pbcn space group with a = 1.6075(4), b = 1.0539(3), c = 0.9195(3) nm, V= 1.5578(7) nm^3, M_r = 352.79, Z = 4, D_c = 1.487 g/cm^3, final R = 0.0451 and wR = 0.1294. Thestructure of 1 indicates that the central Cu(II) atom is penta-coordinated by four nitrogen atoms oftwo DACH moieties at the equatorial positions and a water molecule at the axis position. Thecoordination geometry of Cu(II) could be considered as an approximately ideal square-pyramidalenvironment. Both DACH rings arrange in cis-form and are predominantly in the boat-boat conformation(80%) with some disorder to the chair-chair conformation (20%). The Cl^- anions are hydrogen bondedwith the nitrogen donors of the DACH rings and the oxygen donor of the coordinated H_2O molecule toform a one-dimensional zigzag linear structure. The solution behaviors of 1 are also discussed indetail by Uv-vis and ESR technique.
