Antibacterial polymer composites for implants made of polylactide and polyetheretherketone with zinc oxide: Properties, degradation and efficacy

Abstract

The aim of this study was to integrate an antibacterial agent into implant materials to prevent infection and to investigate the aging behavior of the plastics in physiological solution as a function of filler type and proportion as well as of the process parameters. The active ingredient that is incorporated into the polymer during compounding should remain effective in the body over a long period of time. With varied melt processing conditions, composites made of a biodegradable polylactide (PLA) were mixed with tricalcium phosphate (TCP) and zinc oxide (ZnO) as an antibacterial agent. Hydroxyapatite (HAP) and zinc oxide were incorporated into a non-degradable polyetheretherketone (PEEK). The material properties of the composites were characterised and investigated with regard to their in vitro behaviour. The investigations were carried out with gel permeation chromatography (GPC), differential scanning calorimetry (DSC), tensile tests, recording of the mass change during storage and colony forming units test (CFU). Over the investigated ageing period of 9 months in phosphate buffered saline (PBS) at 37 °C the composites showed antibacterial efficacy against Escherichia coli.