Presenter
Abstract
Poly(ethylene glycol) (PEG) is an established biopolymer that is in clinical use for several decades. It biocompatibilizes substrates by conveying a “stealth character,” meaning the PEGylated substrate is not recognizable by the reticuloendothelial system. Therefore longer blood circulation times are achieved for PEGylated drugs and diminished protein and subsequently cell adhesion, are observed on PEGylated surfaces. However, PEG is chemically inert and therefore cannot be readily attached to a substrate. By forming block copolymers with a poly(amino acid) (PAA), the chemical inertness of PEG is addressed as the PAA blocks act as anchoring moiety for the PEG-b-AA copolymer. Amino-terminated PEG is used as macroinitiator in the ring-opening polymerization of N-carboxyanhydrides of amino acids. The PAA block in itself is also biocompatible as it is formed from naturally occurring amino acids. A variety of chemical architectures will be discussed: If the functional groups of the amino acids are reactive toward the surface of a substrate, the copolymer is useful for surface modifications. If the PAA-block is hydrophobic, the resulting block copolymers will self-assemble to form drug or gene delivery vehicles.