Effects of Amelogenin on Proliferation, Differentiation, and Mineralization of Rat Bone Marrow Mesenchymal Stem Cells In Vitro

The aim of this study was to clarify the function of amelogenin, the major protein of enamel matrix derivative, on the proliferation, differentiation, and mineralization of cultured rat bone marrow stem cells (BMSCs), toward the establishment of future bone regenerative therapies. No differences in the morphology of BMSCs or in cell numbers were found between amelogenin addition and additive-free groups. The promotion of ALPase activity and the formation of mineralized nodules were detected at an early stage in amelogenin addition group. In quantitative real-time RT-PCR, mRNA expression of osteopontin, osteonectin, and type I collagen was promoted for 0.5 hours and 24 hours by addition of amelogenin. The mRNA expression of osteocalcin and DMP-1 was also stimulated for 24 hours and 0.5 hours, respectively, in amelogenin addition group. These findings clearly indicate that amelogenin promoted the differentiation and mineralization of rat BMSCs but did not affect cell proliferation or cell morphology

CuII and CuI Coordination Complexes Involving Two Tetrathiafulvalene-1,3-benzothiazole Hybrid Ligands and Their Radical Cation Salts

International audiencePreparations, crystal structure analyses, and magnetic property investigations on a new CuII(hfac)2 complex coordinated with two TTF—CH═CH—BTA ligands, where hfac is hexafluoroacetylacetonate, TTF is tetrathiafulvalene, and BTA is 1,3-benzothiazole, are reported together with those of its dicationic AsF6– salt, [Cu(hfac)2(TTF—CH═CH—BTA)2](AsF6)2, in which each TTF part is in a radical cation state. In these CuII(hfac)2 complexes, two ligands are bonded to the central Cu atom of the Cu(hfac)2 part through the nitrogen atom of the 1,3-benzothiazole ring and occupy the two apical positions of the Cu(hfac)2 complex with an elongated octahedral geometry. These two ligands are located parallelly in a transverse head-to-tail manner, and the Cu(hfac)2 moiety is closely sandwiched by these two ligands. In the AsF6– salt of the Cu(hfac)2 complex, each TTF dimer is separated by the AsF6– anions and has no overlap with each other within the one-dimensional arrays, resulting in an insulating behavior. Both Cu(hfac)2 complexes showed the simple Curie-like temperature dependence of paramagnetic susceptibilities (χM), indicating that no interaction exists between the paramagnetic CuII d spins. Furthermore, crystal structure analysis and magnetic/conducting properties of a radical cation ReO4– salt of the CuI complex with two TTF—CH═CH—BTA ligands, [Cu(TTF—CH═CH—BTA)2](ReO4)2, are also described. Two nitrogen atoms of the ligands are connected to the central CuI in a linear dicoordination with a Cu–N bond length of 1.879(9) Å. Two TTF parts of the neighboring complexes form a dimerized structure, and such a TTF dimer forms a one-dimensional uniform array along the a direction with a short S–S contact of 3.88 Å. Magnetic property measurement suggested the existence of a strongly antiferromagnetic one-dimensional uniform chain of S = 1/2 spins that originate from the radical cation states of the TTF dimers. Due to the construction of the one-dimensional uniform array of the radical cation state of the TTF dimer along the a axis, a semiconducting behavior is observed with σrt = of 6 × 10–5 S cm–1 and an activation energy of Ea = 0.16 eV

Cu^II and Cu^I Coordination Complexes Involving Two Tetrathiafulvalene-1,3-benzothiazole Hybrid Ligands and Their Radical Cation Salts

Preparations, crystal structure analyses, and magnetic property investigations on a new Cu^II(hfac)₂ complex coordinated with two TTFCHCHBTA ligands, where hfac is hexafluoroacetylacetonate, TTF is tetrathiafulvalene, and BTA is 1,3-benzothiazole, are reported together with those of its dicationic AsF₆^– salt, [Cu­(hfac)₂(TTFCHCHBTA)₂]­(AsF₆)₂, in which each TTF part is in a radical cation state. In these Cu^II(hfac)₂ complexes, two ligands are bonded to the central Cu atom of the Cu­(hfac)₂ part through the nitrogen atom of the 1,3-benzothiazole ring and occupy the two apical positions of the Cu­(hfac)₂ complex with an elongated octahedral geometry. These two ligands are located parallelly in a transverse head-to-tail manner, and the Cu­(hfac)₂ moiety is closely sandwiched by these two ligands. In the AsF₆^– salt of the Cu­(hfac)₂ complex, each TTF dimer is separated by the AsF₆^– anions and has no overlap with each other within the one-dimensional arrays, resulting in an insulating behavior. Both Cu­(hfac)₂ complexes showed the simple Curie-like temperature dependence of paramagnetic susceptibilities (χ_M), indicating that no interaction exists between the paramagnetic Cu^II d spins. Furthermore, crystal structure analysis and magnetic/conducting properties of a radical cation ReO₄^– salt of the Cu^I complex with two TTFCHCHBTA ligands, [Cu­(TTFCHCHBTA)₂]­(ReO₄)₂, are also described. Two nitrogen atoms of the ligands are connected to the central Cu^I in a linear dicoordination with a Cu–N bond length of 1.879(9) Å. Two TTF parts of the neighboring complexes form a dimerized structure, and such a TTF dimer forms a one-dimensional uniform array along the <i>a </i>direction with a short S–S contact of 3.88 Å. Magnetic property measurement suggested the existence of a strongly antiferromagnetic one-dimensional uniform chain of <i>S</i> = 1/2 spins that originate from the radical cation states of the TTF dimers. Due to the construction of the one-dimensional uniform array of the radical cation state of the TTF dimer along the <i>a</i> axis, a semiconducting behavior is observed with σ_rt = of 6 × 10^–5 S cm^–1 and an activation energy of <i>E</i>_a = 0.16 eV

Cu^II and Cu^I Coordination Complexes Involving Two Tetrathiafulvalene-1,3-benzothiazole Hybrid Ligands and Their Radical Cation Salts

Preparations, crystal structure analyses, and magnetic property investigations on a new Cu^II(hfac)₂ complex coordinated with two TTFCHCHBTA ligands, where hfac is hexafluoroacetylacetonate, TTF is tetrathiafulvalene, and BTA is 1,3-benzothiazole, are reported together with those of its dicationic AsF₆^– salt, [Cu­(hfac)₂(TTFCHCHBTA)₂]­(AsF₆)₂, in which each TTF part is in a radical cation state. In these Cu^II(hfac)₂ complexes, two ligands are bonded to the central Cu atom of the Cu­(hfac)₂ part through the nitrogen atom of the 1,3-benzothiazole ring and occupy the two apical positions of the Cu­(hfac)₂ complex with an elongated octahedral geometry. These two ligands are located parallelly in a transverse head-to-tail manner, and the Cu­(hfac)₂ moiety is closely sandwiched by these two ligands. In the AsF₆^– salt of the Cu­(hfac)₂ complex, each TTF dimer is separated by the AsF₆^– anions and has no overlap with each other within the one-dimensional arrays, resulting in an insulating behavior. Both Cu­(hfac)₂ complexes showed the simple Curie-like temperature dependence of paramagnetic susceptibilities (χ_M), indicating that no interaction exists between the paramagnetic Cu^II d spins. Furthermore, crystal structure analysis and magnetic/conducting properties of a radical cation ReO₄^– salt of the Cu^I complex with two TTFCHCHBTA ligands, [Cu­(TTFCHCHBTA)₂]­(ReO₄)₂, are also described. Two nitrogen atoms of the ligands are connected to the central Cu^I in a linear dicoordination with a Cu–N bond length of 1.879(9) Å. Two TTF parts of the neighboring complexes form a dimerized structure, and such a TTF dimer forms a one-dimensional uniform array along the <i>a </i>direction with a short S–S contact of 3.88 Å. Magnetic property measurement suggested the existence of a strongly antiferromagnetic one-dimensional uniform chain of <i>S</i> = 1/2 spins that originate from the radical cation states of the TTF dimers. Due to the construction of the one-dimensional uniform array of the radical cation state of the TTF dimer along the <i>a</i> axis, a semiconducting behavior is observed with σ_rt = of 6 × 10^–5 S cm^–1 and an activation energy of <i>E</i>_a = 0.16 eV