Nanostructured surfaces

Wetting properties of plasma activated and chitosan coated PEEK surfaces
Przykaza K.1, Woźniak K.1, Ładniak A.1 Jurak M.1 Wiącek A.E.1
1 University of Maria Curie-Skłodowska, Faculty of Chemistry, Department of Interfacial Phenomena, Maria Curie-Skłodowska Square 3, 20-031 Lublin, Poland.
E-mail: przykaza.kacper@poczta.umcs.lublin.pl

The polyetheretherketone (PEEK) polymer, which is increasingly used as a bone implant was activated using the low temperature and low pressure air plasma. The increase of micro-roughness and creation of new functional surface groups [1] facilitate adhesion and bonding of various bioactive molecules such as chitosan to their surfaces. Chitosan is a natural polysaccharide which owns antibacterial, antifungal and adsorption properties as well as good biocompatibility. Using the Langmuir-Blodgett (LB) technique the plasma activated and chitosan coated PEEK supports were modified with the thin films of phospholipid - 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), sterol - cholesterol (Chol) and polypeptide - cyclosporine A (CsA). DPPC and Chol are widely used for the film formation on the implant surfaces that mimic the natural cell membrane. The obtained films with lipids should lead to strengthening the intimate interface between the cells and the artificial material. The addition of the immunosuppressive drug - CsA to the one-component DPPC or Chol films resulted in an interesting system that could potentially serve as a carrier for therapeutic substances. The value of the surface free energy of such systems potentially used in contact with the living tissues seems to play a main role in the cell adhesion and osseointegration process. The obtained surfaces were investigated in aspect of wettability and surface free energy changes estimated from contact angle hysteresis (CAH) approach [2]. The obtained surfaces are intended to have a potential application in regenerative medicine to develop biomimetic strategies for artificial bone grafts in the tissue engineering as well to enhance the polymers osseointegration process and simultaneously the drug delivery system.

1.	Wiącek A.E., Terpiłowski K., Jurak M., Worzakowska M. Effect of low-temperature plasma on chitosan-coated PEEK polymer characteristics. European Polymer Journal.-2016.-78.-P. 1-13.
2.	Chibowski E. Surface free energy of a solid from contact angle hysteresis. Advances in Colloids and Interface Science.-2003.-103.-P.149-172.