• Zahida Ademović University of Tuzla, Faculty of Technology, Univerzitetska 8, 75000 Tuzla, B&H
  • Snježana Marić University of Tuzla, Faculty of Science, Univerzitetska 6, 75000 Tuzla, B&H
  • Peter Kingshott Swinburne University of Technology, Hawthorn, Victoria, 3122, Australia
  • Zoran Iličković University of Tuzla, Faculty of Technology, Univerzitetska 8, 75000 Tuzla, B&H




Contact lenses suffer from two limitations: low oxygen permeability and deposition of protein and lipids. In order to prevent bioadhesion, surface must be completely inert to all biological reactions. To achieve this, surface properties must be tailored. Also, to improve comfort, surface must be highly wettable and lubricous. In this paper the surface of silicone contact lenses was modified by plasma induced copolymerization of acrylic acid. A wettable surface was generated and in addition carboxyl groups that were created on the surface provided an ideal reactive platform for subsequent grafting of polyethylene glycol. Each surface modification step was analysed by XPS and contact angle measurements. Lysozyme adsorption on modified silicone contact lenses was analysed by surface-MALDI-ToF-MS and XPS. After incubation with lysozyme, surface-MALDI-TOF-MS and XPS analysis showed a reduction of adsorbed lysozyme on hydrogel modified contact lenses. Surface modification of silicone with PEG is a method for reduction of protein adsorption on contact lenses.


[1] B. D. Ratner, A. S. Hoffman, F. J. Shoen, J. E. Lemons, editors., Biomaterials science: Introduction to Materials in Medicine, 2nd edition. Elsevier Academic Press, London, UK 2004.

[2] J. M. Harris, Poly(Ethylene Glycol) Chemistry: Biotechnical and Biomedical Applications, Plenum Press, New York, 1992.

[3] S. J. Sofia, V. Premnath, E. W. Merrill, Poly(ethylene oxide) Grafted to Silicone Surfaces: Grafting Density and Protein Adsorption, Macromol., Vol. 31 (1998) 5059507.

[4] S. I. Jeon, J. H. Lee, J. D. Andrade, P. G. de Gennes, Protein-surface interactions in the presence of polyethylene oxide: I. Simplified theory, J. Colloid Interface Sci., Vol. 142 (1991) 149158.

[5] I. Szleifer, Protein Adsorption on Surfaces with Grafted Polymers: A Theoretical Approach, Biophys. J., Vol. 72 (1997) 595612.

[6] J. Groll, Z. Ademovic, T. Ameringer, D. Klee, M. Moeller, Comparison of coatings from reactive star shaped PEG-stat-PPG prepolymers and grafted linear PEG for biological and medical applications, Biomacromolecules, Vol. 6 (2005) 956962.

[7] D. Klee, Z. Ademovic, H. Hoecker, A. K. Bosserhoff, G. Maziolisc, H. J. Erli, Surface modification of polyvinylidene fluoride to improve the cell adhesion, Biomaterials, Vol. 24 (2003) 36633670.

[8] Z. Ademović, D. Klee, P. Kingshott, H. Hoecker, Minimization of protein adsorption on polyvinylidene fluoride, Biomolecular Engineering, Vol.19 (2002) 177182.

[9] P. Kingshott, A.W. Heather, S. John, H. Griesser, Direct Detection of Proteins Adsorbed on Synthetic Materials by Matrix-Assisted Laser Desorption Ionization–Mass Spectrometry, Anal. Bio-chem. , Vol. 273 (1999) 156162.

[10] R. A. Sack, B. Jones, A. Antignani, R. Libow, H. Harvey, Specificity and biological activity of the protein deposited on the hydrogel surface. Relationship of polymer structure to biofilm formation, Invest. Ophthalmol. Vis. Sci., Vol. 28 (1987) 842849.