Hydrophilic/Hydrophobic Copolymers: Fluorinated Hydrogels as Biomaterials

Abstract

Bio-organs are generally multi-component systems containing both hydrophilic and hydrophobic parts. Several hydrophobic biodegradable polymers have been successfully used as biomedical materials. They become hydrophilic as they are degraded by hydrolytic and oxidative processes and their biocompatibility improves with the degradation. It is commonly observed that polymer systems with hydrophilic surfaces which become ‘soft’ when swollen with water have better biocompatibility with respect to blood proteins interaction than similar systems with hydrophobic and ‘hard’ surfaces which tend to cause denaturing of the absorbed proteins. We have studied the design, synthesis, characterization, testing, and application of multi-component hydrophilic-hydrophobic biodegradable polymer systems as biomedical materials1–5. These include copolyesters containing hydroxy groups derived from tartaric acid as drug release systems6,7; hydrogen-bond containing poly(enol-ketone)s and poly(amide-enamine) as drug release matrices8; and semi-interpenetrating and interpenetrating networks of polycaprolactone and poly(2-hydroxyethyl methacrylate) as tendon implants9–11. It become clear to us that it is important to control the adhesion/interaction between polymer surfaces and blood proteins. Our aims are two -fold: minimizing the non-specific interactions and maximizing the desirable interactions. Among our approaches is the synthesis of hydrophilic-hydrophobic multi-component polymer system with well-defined structures. We reported here some of our recent results on fluorine containing hydrogel systems.