Crystallisation driven self-assembly
The O’Reilly and Dove groups reported the first living CDSA in aqueous solution using a poly(l-lactide)-b-poly(acrylic acid), PLLA-b-PAA diblock copolymer. These results demonstrate the concept and ability to exert control over the length of the nanoscopic cylinders using polymers that can be synthesised in an easily accessible manner. Beyond this study, we have investigated the mechanism of the cylinder growth and also demonstrated that the cylinder dimensions can be readily controlled by changing the composition of the diblock copolymer over a wide composition. Furthermore, we have demonstrated that other water soluble shell-forming blocks can be applied in these techniques. We have extensively studied the long term and low concentration stability of these particles. In contrast to particles in which the hydrophobic effect is responsible for their stability, the crystalline nature of the core of the particles that we use ensures high stability. We have also reported the design and preparation of a number of stimuli responsive nanostructures (pH, temperature, stereocomplexation and dehydration) and explored their response in a range of applications including controlled release. These chemistries can now be utilised within our platform particles to allow for uptake and triggered release. Importantly using CDSA gives us the ability to control the dimensions of the assemblies, their degradation and anisotropy – this cannot be achieved using standard assembly techniques.