No abstract

One of the great challenges in stereochemistry is the explanation of why some molecules resolve spontaneously while others do not. In this critical review the recent advances in the creation of chiral systems from achiral and racemic compounds in three-, two- and one-dimensional systems are discussed. There are some groups of molecules in some systems that do tend to display conglomerates, which may suggest that there are enantiophobic and enantiophilic molecules whose assembly is guided by the structural and thermodynamic properties of the systems in question.

Photodynamic therapy (PDT) is a treatment of cancer by which tumour cells are destroyed using reactive oxygen species produced by photosensitisers following activation with visible or near infrared light. Successful PDT depends on the solubility and the targeting ability of the photosensitisers. In this work, the synthesis of a porphyrin-based water soluble nanoparticle conjugate containing a targeting agent that recognises the erbB2 receptor overexpressed on the surface of particular cancer cells is reported. The nanoparticle conjugates were synthesised following two different protocols, viz. a biphasic and a monophasic method, with the aim to determine which method yielded the optimal nanosystem for potential PDT applications. The nanoparticles were characterised using UV-Vis absorption and fluorescence spectroscopies together with transmission electron microscopy and zeta potential measurements; and their ability to produce singlet oxygen following irradiation was investigated following the decay in absorption of a singlet oxygen probe. The nanoparticles synthesised using the monophasic method were shown to produce the highest amount of singlet oxygen and were further functionalised with anti-erbB2 antibody to target the erbB2 receptors expressed on the surface of SK-BR-3 human breast cancer cells. The water soluble, antibody-porphyrin nanoparticle conjugates were shown to elicit targeted PDT of the breast cancer cells.