Publicaciones 2011-2020

@article{RN324,
title = {Effect of Shape and Bending Modulus on the Properties of Nematic Lyotropic Liquid Crystals},
author = { A. Ruiz-Fernandez and J.J. Lopez-Cascales and J.J. Giner-Casares and R. Araya-Maturana and F.G. Diaz-Banose and D. Munoz-Gacitua and B. Weiss-Lopez},
url = {/brokenurl#<Go to ISI>://WOS:000369515500071},
doi = {10.1039/c5ra24019k},
year = {2016},
date = {2016-01-01},
journal = {Rsc Advances},
volume = {6},
number = {9},
pages = {7455-7464},
abstract = {Synovial liquid is a natural lubricant of articular joints, such as shoulders, knees and hips. Thus, the development of biocompatible lubricants that can be employed in medical prosthesis for artificial implants, and eventually in certain therapies against osteo-arthritis or rheumatoid-arthritis diseases, is of an undoubted importance. Lyotropic liquid crystals have been used in the synthesis of silica and metals containing regularly oriented nanoporous, to obtain oriented carbon nanotube materials, in several pharmaceutical applications, as membrane mimetics and in lubrication applications. In this context, a new nematic lyotropic liquid crystal has been developed based on tetradecyltrimethyl ammonium chloride (TTAC), decanol (DeOH), a natural mixture of lipids (PL) extracted from soybean and sodium chloride (NaCl), all dissolved in water. A 30% w/w increase in TTAC content respect a certain composition of reference produces a more than 24-fold increase in the macroscopic viscosity of the solution. To understand the molecular principles that explain this behavior, several experimental and theoretical studies have been carried out. In this regard, H-2-NMR quadrupole splittings of fully deuterated sodium dodecyl sulphate (SDS-d(25)) introduced as molecular probe, transmission electron microscopy (TEM), freeze fracture transmission electron microscopy (FF-TEM), cryogenic transmission electron microscopy (Cryo-TEM) and polarized light microscopy (PLM) were obtained. In addition, hydrodynamic studies determined how the enhancement in viscosity requires a change in the shape of the aggregate, from circular to elliptic. Finally, molecular dynamics simulations allowed to estimate how variations in the bending modulus, k(b), can explain the observed tendency of the quadrupole splittings, on the basis of a modification in the flexibility of the aggregate.},
keywords = {bilayers, carbon ewald, h-2 lubrication, macromolecules, matter, mesh molecular-dynamics nanotubes, particle rigidity, simulations, systems},
pubstate = {published},
tppubtype = {article}
}

@article{RN213,
title = {Thermodynamics and (Hnmr)-H-2 Study on the Insertion of Small Quinones into a Discotic Nematic Lyotropic Liquid Crystal},
author = { V.E. Bahamonde-Padilla and J.J. Lopez-Cascales and R. Araya-Maturana and M. Martinez-Cifuentes and B. Weiss-Lopez},
url = {/brokenurl#<Go to ISI>://WOS:000335515900018},
doi = {10.1002/cphc.201301146},
issn = {1439-4235},
year = {2014},
date = {2014-01-01},
journal = {Chemphyschem},
volume = {15},
number = {7},
pages = {1422-1431},
abstract = {A detailed description of the distribution, interaction, and dynamics of molecules with biological activity dissolved in a hydrophobic bilayer, a simple model of a biological membrane, provides valuable information for a better understanding of drug functioning, which can be very useful in drug design. Here we present an H-2 NMR and molecular dynamics study on the insertion, distribution, interactions, and thermodynamics of two biologically active molecules, 9,10-dihydroxy-4,4-dimethyl-1,4,5,8-tetrahydroanthracen-1-one (HQ), with anticancer activity, and 4,4-dimethyl-1,4,5,8,9,10-hexahydroanthracen-1,9,10-trione (Q) a fungicide, dissolved in a nematic discotic lyotropic liquid crystal (ndllc) composed of sodium dodecylsulphate (SDS), decanol (DecOH) and Na2SO4 in water. H-2 NMR quadrupole splittings ((Q)) and longitudinal relaxation times (T-1) from HQ-d(6), Q-d(4), DecOH--d(2), partially deuterated water, and SDS-d(25) were measured and several molecular dynamics trajectories were also calculated. In particular, G, H, and S profiles for the process of both molecules crossing the bilayer were estimated. It was evidenced that the insertion of both molecules into the aggregate is a spontaneous process, and the molecules are mainly distributed in the internal side of the interface. Addition of HQ or Q decreased the mobility of all aggregate components, but this effect was more pronounced for HQ. The rotational correlation time of Q allowed an estimate of 5.3 cP for the microviscosity inside the ndllc aggregate, in the order of previously measured values in similar environments. Both guest molecules display similar free-energy profiles for the process of crossing the bilayer, with a calculated barrier height of 25 and 36 kJmol(-1) for HQ and Q, respectively.},
keywords = {aqueous-solution, crystals, derivatives, dynamics, ewald, force-field, free-energy, lipid-bilayer, liquid membrane, mesh micelle microviscosity, molecular molecular-dynamics nmr particle quinones, resonance, simulations, spectroscopy},
pubstate = {published},
tppubtype = {article}
}

@article{RN100,
title = {Location, Orientation and Dynamics of Two Molecules with Mitochondrial Activity Dissolved in Anionic Lyomesophase. A H-2-Nmr and Md Study},
author = { V.E. Bahamonde-Padilla and M. Martinez-Cifuentes and D. Munoz-Masson and A.I. Ruiz and H. Ahumada and R. Araya-Maturana and J. Soto-Delgado and B. Weiss-Lopez},
url = {/brokenurl#<Go to ISI>://WOS:000309315300021},
doi = {10.4067/S0717-97072012000300021},
issn = {0717-9707},
year = {2012},
date = {2012-01-01},
journal = {Journal of the Chilean Chemical Society},
volume = {57},
number = {3},
pages = {1295-1300},
abstract = {4,4-Dimethyl-5,8-dihydroanthracene-1,9,10(4H)-trione (Q1) and 9,10-Dihydroxy-4,4-dimethyl-5,8-dihydro-1 (4H)-anthracenone (Q2), two molecules that inhibit cancer cell respiration, were selectively deuterated and dissolved in an anionic discotic nematic lyotropic liquid crystal (dnllc) solution. The solution provides a magnetic field oriented anisotropic medium, where the location, average orientation and dynamics of Q(1) and Q(2) were examined by measuring H-2-NMR quadrupole splittings (Delta v(Q)) and H-2 longitudinal relaxation times (T-1). The NMR data shows that both molecules are strongly attached to the aggregate and, when dissolved, increase the alignment of the interface components with the magnetic field. However they present different average orientations. To assist with the interpretation of the experimental results, 300ns Molecular Dynamics (MD) trajectories of a bilayer model of the aggregate were calculated. The results show that both molecules spontaneously diffuse inside the bilayer, to locate in the limit between the hydrophobic core and the interface. The orientations of both molecules in the aggregate are determined by the formation of H-bonds with water.},
keywords = {antioxidant, derivatives, deuterium dipalmitoylphosphatidylcholine, hydration, hydroquinones, longitudinal lyomesophase, parathion, peptides, proteins quadrupole quinones, relaxation respiration, simulations, splitting, time, tumor-cell},
pubstate = {published},
tppubtype = {article}
}