Polymeric neoglycoconjugates : synthesis, characterisation and properties
As part of a currently intense research effort into the development of novel potent macromolecular pharmaceuticals, diagnostic tools and carriers for targeted drug delivery, this project involved the synthesis of glycopolymers. Polymethacrylate derivatives carrying carbohydrate residues were efficiently prepared in a stereo-controlled manner, following two different routes. As revealed by a thorough characterisation of the materials obtained, the synthetic procedure strongly affected the polymers' composition and, in turn, their properties, such as their self-association in aqueous media and the interaction of the compounds bearing D-galactose units with a specific lectin. Polymers containing peracetylated saccharide residues were shown to be surface-active, forming stable spread Langmuir films. These monolayers acted as effective dl-aspartic acid nucleation promoters, whilst the soluble analogues (for which the sugars are deacetylated) seemed to possess a certain activity as dl-aspartic acid growth inhibitors. The behaviour of the deprotected polymers in aqueous solution was thoroughly investigated, prior to testing whether the materials carrying galactosyl units on the side chains could be recognised by a galactose-specific protein. For the first time for polymeric glycoconjugates, thermodynamic binding parameters relative to this protein-carbohydrate interaction were directly evaluated using isothermal titration microcalorimetry.