Immobilization of chitosan on polyether ether ketone surface modified with acrylic acid by UV-induced graft polymerization

Polyether ether ketone (PEEK) is a promising bioengineering material with good mechanical properties, high aging resistance and low water absorption, but it is biologically inert that may limit its medical applications. In this study, ultraviolet (UV)-induced graft polymerization was used in combination with wet chemical treatment for immobilization of chitosan (CS) on PEEK surface. Carboxyl groups were introduced onto PEEK surface by UV-induced graft polymerization of acrylic acid (AAc), and then CS was immobilized onto PEEK surface by the reaction between the acid groups of AAc and amino groups of CS. The graft polymerization was evaluated by attenuated total reflectance Fourier-transformed infrared (ATR-FTIR) spectroscopy, contact angle (CA) measurement, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS), and the grafting degree was evaluated by changes in the masses of PEEK before and after modification. The results showed that the grafting degree of CS could be controlled within 1.58–2.98% by adjusting the CS solution concentration, and the hydrophilicity of CS-grafted PEEK was higher than that of the unmodified PEEK. The antibacterial results showed that PEEK grafted with CS has good antibacterial activity. This study provided an effective and convenient method for preparing functional PEEK materials with good antibacterial activity. Graphical abstract