99668-71-0Relevant articles and documents
Chitosan Immobilization on Bio-MOF Nanostructures: A Biocompatible pH-Responsive Nanocarrier for Doxorubicin Release on MCF-7 Cell Lines of Human Breast Cancer
Abazari, Reza,Mahjoub, Ali Reza,Ataei, Farangis,Morsali, Ali,Carpenter-Warren, Cameron L.,Mehdizadeh, Kayhan,Slawin, Alexandra M. Z.
, p. 13364 - 13379 (2018/10/31)
In this work, a bio-metal-organic framework (Bio-MOF) coated with a monodispersed layer of chitosan (CS; CS/Bio-MOF) was synthesized and applied as a pH-responsive and target-selective system for delivery of doxorubicin (DOX) in the treatment of breast cancer. The efficiency of the nanocarrier in loading and releasing DOX was assessed at different pH levels. To monitor the in vitro drug release behavior of the drug-loaded carrier, the carrier was immersed in a phosphate buffered saline solution (PBS, pH 7.4) at 37 °C. According to the observations, the nanocarrier presents a slow and continuous release profile as well as a noticeable drug loading capacity. In addition, the carrier demonstrates a pH-responsive and target-selective behavior by releasing a high amount of DOX at pH 6.8, which is indicative of tumor cells and inflamed tissues and releasing a substantially lower amount of DOX at higher pH values. In addition, the results indicated that pH is effective on DOX uptake by CS/Bio-MOF. A 3.6 mg amount of DOX was loaded into 10 mg of CS/Bio-MOF, resulting in a 21.7% removal at pH 7.4 and 93.0% at pH 6.8. The collapsing and swelling of the CS layers coated on the surface of the Bio-MOFs were found to be responsible for the observed pH dependence of DOX delivery. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the trypan blue test were performed on the MCF-7 (breast cancer) cell line in the presence of the CS/Bio-MOF carrier to confirm its biological compatibility. In addition, Annexin V staining was conducted to evaluate the cytotoxicity of the free and loaded DOX molecules. On the basis of the obtained optical microscopy, MTT assay, fluorescence microscopy, and dyeing results, the CS/Bio-MOF carrier greatly enhances cellular uptake of the drug by the MCF-7 cells and, therefore, apoptosis of the cells due to its biocompatibility and pH-responsive behavior.
Carbon-Oxygen Bond Cleavage of Esters Promoted by Hydrido and Alkylcobalt(I) Complexes Having Triphenylphosphine Ligands. Isolation of an Insertion Intermediate and Molecular Structure of Phenoxotris(triphenylphosphine)cobalt(I)
Hayashi, Yoshinori,Yamamoto, Takakazu,Yamamoto, Akio,Komiya, Sanshiro,Kushi, Yoshihiko
, p. 385 - 391 (2007/10/02)
Carbon-oxygen bonds in aryl and alkyl carboxylates (R'COOR) are selectively cleaved by CoH(N2)(PPh3)3, and carboxylic esters R'COOCH2R' are formed by a Tischchenko type dimerization of aldehyde R'CHO, whereas the reaction of CoMe(PPh3)3 with the esters yields ketones R'COMe.The reaction products are accounted for by assuming insertion of the ester C=O double bond into the Co-H or Co-Me bond, followed by abstraction of the β-alkoxo group by cobalt.The intermediate (β-(ethoxy)alkoxo)cobalt(I) complex Co(OCH(CF3)OEt)(PPh3)3 has been isolated in the reaction of CoH(N2)(PPh3)3 with ethyl trifluoroacetate as well as by alcoholysis of CoH(N2)(PPh3)3 with CF3CH(OEt)OH.Treatment of CoH(N2)(PPh3)3 with phenyl acetate affords a tetrahedral phenoxocobalt(I) complex, Co(OPh)(PPh3)3.Crystals of the complex are monoclinic, space group P21/c, with a = 13.142(2) Angstroem, b = 19.661(3) Angstroem, c = 18.714(3) Angstroem, and β = 91.49(3) degree.Block-diagonal least-squares refinement leads to R = 0.075 and Rw = 0.081 for 2966 reflections.The molecular structure of the complexe consists of a tetrahedron with an O-bonded phenoxo group and three PPh3 ligands; the average Co-P distance is 2.320(4) Angstroem and Co-O 1.900(9) Angstroem, and the average P-Co-P angle is 109.9(1) degree, P-Co-O 109.1(4) degree, and Co-O-C 138.2(9) degree, respectively.
