Surface modifications based on the cyanobacterial siderophore anachelin: from structure to functional biomaterials design

This review describes the design, synthesis and evaluation of novel catechol based anchors for surface modification. The anachelin chromophore, the catecholate fragment of the siderophore anachelin from the cyanobacterium Anabaena cylindrica, allows for the immobilization of polyethylene glycol (PEG) on titania and glass surfaces thus rendering them protein resistant and antifouling. It is proposed that catecholate siderophores constitute a class of natural products useful for surface modification similar to dihydroxyphenylalanine and dopamine derived compounds found in mussel adhesive proteins. Second-generation dopamine derivatives featuring a quaternary ammonium group were found to be equally efficient in generating antifouling surfaces. The anachelin chromophore, merged via a PEG linker to the glycopeptide antibiotic vancomycin, allowed for the generation of antimicrobial surfaces through an operationally simple dip-and-rinse procedure. This approach offers an option for the prevention of nosocomial infections through antimicrobial implants, catheters and stents. Consequences for the mild generation of functional biomaterials are discussed and novel strategies for the immobilization of complex natural products, proteins and DNA on surfaces are presented.