Protein-imprinted polysiloxane scaffolds

Molecular imprinting is a technique used to create specific recognition sites on the surface of materials. Although widely developed for chromatographic separation of small molecules, this approach has not been adequately investigated for biomaterial applications. Thus, the objective of these experiments was to explore the potential of molecular imprinting for creating biomaterials that preferentially bind specific proteins. Macroporous polysiloxane (silica) scaffolds were imprinted with either lysozyme or RNase A using sol–gel processing. The quantity of surface-accessible protein, which was related to the number of potential binding sites, was varied by changing the amount of protein loaded into the sol. Up to 62% of loaded protein was accessible. The amount of protein per unit surface area ranged from 0.3 μg m−2 for low loading of RNase to 152 μg m−2 for high loading of lysozyme. Protein-imprinted scaffolds were then evaluated for their ability to preferentially recognize the template biomolecule when incubated in mixtures containing both the imprinted protein and a competitor protein of comparable size (approximately 14 kD). In solutions containing a single protein, up to 3.6 times more template bound compared with the competitor. Furthermore, in solutions containing equal amounts of both molecules, the porous scaffolds bound up to three times more template than the competitor protein, which is a level of preferential binding similar to values reported in the molecular imprinting literature for both organic and inorganic materials.