WETTING PROPERTIES OF CHITOSAN-MODIFIED AND PLASMA-TREATED PEEK SURFACES

Abstract

In this paper, the wettability of chitosan/phospholipid (1,2-dipalmitoyl-sn-glycero-3-phosphocholine – DPPC), chitosan/lipid (cholesterol – Chol) and chitosan/protein (cyclosporine A – CsA) films on air plasma activated polyetheretherketone (PEEK) plates was studied. The layers were prepared using the solution spreading technique and their surface wetting properties were determined based on the measurements of the advancing and receding contact angles of water, formamide and diiodomethane. Moreover, based on the contact angle hysteresis model of Chibowski, values of total surface free energy were estimated. Significant changes in PEEK polarity were observed after plasma activation and modifications with Ch/DPPC, Ch/Chol and Ch/CsA layers. These molecules modulate the chitosan film surface by changing the type and magnitude of interactions, which is revealed in the values of surface free energy. These results may be important for the development and implementation of highly biocompatible bone substitution polymers coated with chitosan film with anti-fungal and anti-bactericidal properties. Those systems based on chitosan may also carry and release biologically active substances which could be relevant in the new generation of drug delivery systems.