Lysine based amorphous polyurethanes decorated with pendant bio-active groups

PhD ceremony: Ms. J. Yin, 16.15 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Lysine based amorphous polyurethanes decorated with pendant bio-active groups

Promotor(s): prof. J.A. Loontjens

Faculty: Mathematics and Natural Sciences

Due to a wide range of physical and chemical properties, polyurethanes (PUs) are used in numerous applications like coatings, foams, fibers, engineering plastics and biomaterials. The use of biomaterials for medical implants is rapidly growing due to the aging of the world population and because it is not accepted anymore to live with loss of function due to trauma or wear. Depending on the composition, polyurethanes can fulfill all these requirements and have to be selected accordingly. It is convenient to synthesize polyurethanes from diisocyanates (DIs) since the DIs are reactive towards alcohols at low temperature, when catalyzed, and with amines without catalysts. However, the high reactivity and toxicity of isocyanates do not allow contamination of the body by traces of remnant. Temporarily blocking the isocyanate groups could be an attractive alternative, while still affording the same polyurethanes with polyols. They are less reactive and therefore possibly suitable to introduce bio-active moieties. My project studies the synthesis of linear or crosslinked polyurethanes from caprolactam blocked lysine diisocyanate (BLDI), which were provided with functional side groups. A novel synthetic methodology to prepare BLDI was developed. By making use of the expected stability of BLDI and the presence of a pendant ester group, the introduction bio-functional side groups like GRGDG and biotin via that pendant ester group was studied. Amorphous polymer networks were studied to avoid the presence of remnant polymer crystals after degradation. Some preliminary experiments with human cells were employed to demonstrate the biocompatibility of the resulting polyurethanes.