Effect of steam sterilization on poly(ether-ester)s copolymer and its vascular cell compatibility

The aim of this research was to evaluate the influence of steam sterilization on poly(ethylene glycol-terephthalate) and poly(butylene terephthalate) copolymer (PEGT/PBT) and its vascular cells compatibility, which was used as the scaffolds in vascular tissue engineering. Endothelial cells, smooth muscle cells and fibroblasts were cultured separately on the films after steam sterilization and after ultraviolet sterilization. These cells can grow well on the films after ultraviolet sterilization, while they can hardly adhere on steam sterilized films. Differential scanning calorimetry, static contact angle, X-ray photoelectron spectroscopy, surface carboxyl density quantity, H-nuclear magnetic resonance and scanning electronic microscope were employed to characterize the properties of poly(ether-esters) films before and after sterilization. These results showed that steam sterilization had little effect on the surface morphology and on the constitution of the copolymer, but the copolymer segments were redistributed during steam sterilization. The hydrophilic poly(ethylene glycol) (PEG) and the end carboxyl groups transferred from the bulk and enriched on the surface and the degree of crystallinity of hard segments increased slightly. Both the end carboxyl and PEG enriched on the surface can hinder the protein adhesion on the surface; so, lacking in receptor, the vascular cells cannot adhere on the films surfaces.