Functionalization of Biodegradable Polyester for Tissue Engineering Applications

Summary: Chemical modification of polymer surface may potentially be used to create smart materials that can guide cellular adhesion, proliferation and maintenance of specific expression of molecules. The microbial polyester poly (3-hydroxybutyrate) (PHB) has been attracted attention as promising material for applications in tissue engineering. In this work, a wet-chemical method, base ethylenediamine aminolysis, was performed to improve the adhesion of chondrocytes isolated from human articular cartilage to PHB films. The effects of chemical treatment on PHB films was evaluated by following changes in morphology and surface chemical composition using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), respectively. While the effect on cells morphology was studied by scanning electron microscopy (SEM). The treatment with ethylenediamine did not change significantly the morphology of the structures of PHB films surface. However, the roughness of the aminolyzed films was slightly higher. The introduction of nitrogen-containing groups was confirmed by XPS. In vitro experiments indicated that the surface modification did not have toxic effects in cells, since they could adhere and proliferate on modified PHB films. It was observed that long-time treatment improved ability of PHB films to support cell growth, which could be accounted to physicochemical and topological effects.