The self-assembled structures covered by Nelson are not only observed with surfactants and phospholipids, they are found for almost all amphiphilic molecules in solution (amphiphilic meaning that the molecules have both polar and non-polar regions). The structures that amphiphilic molecules form are the result of the free energies associated with the solute and solvent system. The figure below illustrates how varied these structures can be when you change the relative concentrations of surfactant, polar solvent and non-polar solvent. (Note that what isn't included in this figure is the dependence of structure on surfactant chain length, headgroup properties or counter-ion concentration.)
As demonstrated by the next figure (below), these structures can be used as nano-engineering templates. (Apologies for the image quality, blogger seems to be reducing the resolution for some reason.)
Another flavour of amphiphile often used in nano-engineering are block copolymers, these are polymers which have both polar and non-polar monomer units arranged in blocks. The blocks can be joined in various topological arrangements (i.e. combs, stars, branches etc.) and will self-assemble into a vast number of structures depending on their environment. The figure below shows some of the structures observed for a simple linear block copolymer.
A lot of research is being done at the moment into modifying the solubility properties of the copolymers by slightly altering their environment (e.g. pH, temperature.) That way the structure of a block copolymer in solution can be switched by small changes to the surroundings. If this can be achieved in biological conditions, many believe it could provide a viable method for targeted drug delivery.
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