Non-covalent interactions between sertraline stereoisomers and 2-hydroxypropyl-ß-cyclodextrin: a quantum chemistry analysis.

Inclusion compounds formed between sertraline stereoisomers and ß-cyclodextrin, and 2-hydroxypropyl-ß-cyclodextrin, were analyzed by using quantum chemistry methods. The exploration of the potential energy surface was performed using chemical intuition and classical molecular mechanics. This approach delivered around 200 candidates for low energy adducts, which were optimized through the PBE0/6-31G(d,p) method, and after this process solvent effects were considered by the continuous solvent model. This analysis showed that ß-cyclodextrin and 2-hydroxypropyl-ß-cyclodextrin are good trappers of sertraline, although the isomers suggested by molecular dynamics presented higher binding energies than those obtained by chemical intuition. The role of hydrogen bonds in the formation of adducts was studied using the non-covalent interactions index and the quantum theory of atoms in molecules. In this article we concluded that these interactions are present in all adducts, however, they are not important in the stabilization of these inclusion compounds. The molecular electrostatic potential indicates that Coulomb interactions could be responsible for the formation of these systems, although sophisticated solvent models must be used to confirm this conclusion, which are impractical in this case because of the sizes involved in these systems.

Hydrogen bonding capabilities of group 14 homologues of HCN and HNC.

This study is directed towards assessing hydrogen bond acceptor/donor capabilities of heavier group 14 homologues of HCN and HNC. A structural, energetic and topological study using ab initio (MP2, CCSD(T)), electrostatic potential (EP) and quantum theory of atoms in molecules (QTAIM) methodologies was carried out on HNX⋯HNX and HXN⋯HXN dimers and their respective monomers, where X = C, Si, Ge, Sn and Pb. The obtained results suggest the presence of weak hydrogen bonds in both kinds of complexes, and remarkably Ge and Sn act as unconventional hydrogen donors.

Radiolabelled nanoparticles: novel classification of radiopharmaceuticals for molecular imaging of cancer.

Nanotechnology has been used for every single modality in the molecular imaging arena for imaging purposes. Synergic advantages can be explored when multiple molecular imaging modalities are combined with respect to single imaging modalities. Multifunctional nanoparticles have large surface areas, where multiple functional moieties can be incorporated, including ligands for site-specific targeting and radionuclides, which can be detected to create 3D images. Recently, radiolabeled nanoparticles with individual properties have attracted great interest regarding their use in multimodality tumor imaging. Multifunctional nanoparticles can combine diagnostic and therapeutic capabilities for both target-specific diagnosis and the treatment of a given disease. The future of nanomedicine lies in multifunctional nanoplatforms that combine the diagnostic ability and therapeutic effects using appropriate ligands, drugs, responses and technological devices, which together are collectively called theranostic drugs. Co-delivery of radiolabeled nanoparticles is useful in multifunctional molecular imaging areas because it comprises several advantages based on nanoparticles architecture, pharmacokinetics and pharmacodynamic properties.