RAFT polymers for tissue regeneration

Abstract

The number of patients with minor and major accidents coming into accident and emergency care is steadily rising due to increasing life spans and the aging of our society. In order to ensure efficient care and health of human beings, medical methods need to be optimized. The fixation and adhesion between tissues, implants or scaffolds have to be refined, but the number and versatility of biomimetic and biocompatible adhesives that can be used for such purpose is limited. In the last few years studies of phosphorus-based polymers have attracted attention because of their large variety of applications. In the field of adhesion promotors and tissue engineering they have been subject of great interest. These phosphorus-based materials are proved to be biodegradable, blood-compatible and led to strong interactions with bones, enamel or dentin. The problem in measuring the adhesion properties of bone glue is to distinguish between cohesive and adhesive behavior and little information is known from processes at the molecular level. In this thesis, new approach is to measure the adhesion via single molecule force microscopy (SMFM). Therefore, AFM tips had to be functionalized to investigate the adhesion of two amino acid sequences, of a dopamine compound and of the adhesive block copolymers on different substrates. We were interested in the development of such polymers for adhesion properties. Therefore, phosphorus-containing methacrylates were polymerized via reversible addition-fragmentation chain transfer (RAFT) polymerization. This polymerization technique had proved to be a highly versatile and widely applicable living radical polymerization method. It allows the synthesis of well-defined polymers with different architectures. Hence, it is possible to form a narrow distributed block copolymer. These block copolymers can bind to hydroxyl, carboxylic or amino groups of the organic collagen of a bone and form complexes with Ca2+ ions in the inorganic components.