Patient-specific 3D scanned and 3D printed antimicrobial polycaprolactone wound dressings

Abstract

The increasing prevalence of wound infections caused by antibiotic resistant bacteria is an urgent challenge facing modern medicine. To address this issue the expedient use of antimicrobial metals such as zinc, copper and silver were incorporated into an FDA-approved polymer (polycaprolactone - PCL) to produce filaments for 3D printing. These metals have broad-spectrum antimicrobial properties, and moreover, copper and zinc can enhance the wound healing process. 3D scanning was used to construct 3D models of a nose and ear to provide the opportunity to customize shape and size of a wound dressing to an individual patient. Hot melt extrusion was used to extrude pellets obtained by vacuum-drying of solutions of PCL and the different metals in order to manufacture metal-homogeneously-loaded filaments. Wound dressings with different shapes were produced with the filaments containing different concentrations of metals. Release of the metals from the dressings was determined by inductively coupled plasma atomic emission spectroscopy. All the different metal dressings show fast release (up to 24h) followed by slow release (up to 72h). The antibacterial efficacy of the wound dressings was tested using a thermal activity monitor system, revealing that silver and copper wound dressings had the most potent bactericidal properties. This study shows that 3D scanning and 3D printing, which are becoming simpler and more affordable, have the potential to offer solutions to produce personalised wound dressings.

Keywords: 3D printing; 3D scanning; Additive manufacturing; Personalised medicine; Polycaprolactone; Wound dressings.