RESUMEN
We have previously synthesized and characterized the chrysin coordination complex with the oxidovanadium(IV) cation (VIVO(chrys)2) and characterized in ethanolic solution and in solid state. Because suitable single crystals for X-ray diffraction determinations could not be obtained, in the present work, we elucidate the geometrical parameters of this complex by computational methodologies. The optimization and vibrational investigation were carried out both in ethanolic solution and in gas phase. The computational results support the experimentally proposed geometries of the VIVO(chrys)2 complex, thus leading to the conclusion that the complex exists as conformers with trans-octahedral geometry in ethanolic solution and as conformers with cis-octahedral geometry in the solid state. The complex also exists as conformers with trans-octahedral geometry in aqueous media. The active species formed after dissolution in DMSO showed anticancer and antimetastatic behavior in human lung cell line A549 with moderate binding (Kaca. 105 M-1) to bovine serum albumin (BSA). The interaction through hydrogen bonding and van der Waals forces resulted in a spontaneous process. Site marker competitive experiments showed binding sites for chrysin mainly located in site II (subdomain IIIA) and in site I (subdomain IIIA) for the complex. FT-IR spectral measurements showed evidences of the alterations of protein secondary structure in the presence of chrysin and VIVO(chrys)2.
Asunto(s)
Antineoplásicos/farmacología , Movimiento Celular/efectos de los fármacos , Complejos de Coordinación/farmacología , Flavonoides/farmacología , Albúmina Sérica Bovina/metabolismo , Compuestos de Vanadio/farmacología , Células A549 , Animales , Antineoplásicos/química , Antineoplásicos/metabolismo , Sitios de Unión , Bovinos , Supervivencia Celular/efectos de los fármacos , Complejos de Coordinación/química , Complejos de Coordinación/metabolismo , Flavonoides/química , Flavonoides/metabolismo , Humanos , Estructura Molecular , Unión Proteica , Conformación Proteica/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Albúmina Sérica Bovina/química , Compuestos de Vanadio/química , Compuestos de Vanadio/metabolismoRESUMEN
A γ-irradiated bovine albumin serum-based nanoparticle was characterised structurally, and functionally. The nanoparticle was characterised by A.F.M., D.L.S, zeta potential, T.E.M., gel-electrophoresis, and spectroscopy. We studied the stability of the nanoparticle at different pH values and against time, by fluorescence spectroscopy following the changes in the tryptophan environment in the nanoparticle. The nanoparticle was also functionalized with Folic Acid, its function as a nanovehicle was evaluated through its interaction with the hydrophobic drug Emodin. The binding and kinetic properties of the obtained complex were evaluated by biophysical methods as well as its toxicity in tumor cells. According to its biophysics, the nanoparticle is a spherical nanosized vehicle with a hydrodynamic diameter of 70â¯nm. Data obtained describe the nanoparticle as nontoxic for cancer cell lines. When combined with Emodin, the nanoparticle proved to be more active on MCF-7 cancer cell lines than the nanoparticle without Emodin. Significantly, the albumin aggregate preserves the main activity-function of albumin and improved characteristics as an excellent carrier of molecules. More than carrier properties, the nanoparticle alone induced an immune response in macrophages which may be advantageous in vaccine and cancer therapy formulation.
Asunto(s)
Portadores de Fármacos/química , Emodina/administración & dosificación , Nanopartículas/química , Albúmina Sérica Bovina/química , Animales , Sistemas de Liberación de Medicamentos , Emodina/farmacología , Ácido Fólico/química , Rayos gamma , Humanos , Concentración de Iones de Hidrógeno , Células MCF-7 , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones , Microscopía de Fuerza Atómica , Microscopía Electrónica de Transmisión , FN-kappa B/metabolismo , Nanopartículas/toxicidad , Albúmina Sérica Bovina/farmacología , Albúmina Sérica Bovina/toxicidad , Espectrometría de FluorescenciaRESUMEN
In this work, we have studied the interaction between the anticancer drug doxorubicin (doxo) and condensed DNA, using optical tweezers. To perform this task, we use the protein bovine serum albumin (BSA) in the working buffer to mimic two key conditions present in the real intracellular environment: the condensed state of the DNA and the abundant presence of charged macromolecules in the surrounding medium. In particular, we have found that, when doxo is previously intercalated in disperse DNA, the drug hinders the DNA condensation process upon the addition of BSA in the buffer. On the other hand, when bare DNA is firstly condensed by BSA, doxo is capable to intercalate and to unfold the DNA condensates at relatively high concentrations. In addition, a specific interaction between BSA and doxo was verified, which significantly changes the chemical equilibrium of the DNA-doxo interaction. Finally, the presence of BSA in the buffer stabilizes the double-helix structure of the DNA-doxo complexes, preventing partial DNA denaturation induced by the stretching forces.