Vacuum ultraviolet treatment of polyethylene to change surface properties and characteristics of protein adsorption.

The effects of vacuum ultraviolet (VUV) treatment on surface chemical composition morphology and albumin adsorption for low-density polyethylene (LDPE) and high-density polyethylene (HDPE) were investigated. The attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectra and contact angle measurements indicated the formation of oxygen-containing polar groups and double bonds under VUV photooxidation in the presence of air or under VUV irradiation in vacuum. Scanning electron microscopy revealed the development of regular structure with the period about 1 microm on the surface of LDPE and HDPE during VUV photooxidation. The correlation between amount of tightly adsorbed albumin and surface concentration of carboxyl groups generated by VUV irradiation was found. The aging effect for protein adsorption during long storage of VUV irradiated samples in air or phosphate-buffered saline (PBS) was studied. The obtained results prove the VUV irradiation provides a high potential to regulate protein adsorption on polymers for biomedical applications. Copyright 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 428-435, 2004