An artist’s impression of bacteria being destroyed by the new ferroelectric composite material. Image: University of Bath.
An artist’s impression of bacteria being destroyed by the new ferroelectric composite material. Image: University of Bath.

For the first time, engineers at the University of Bath, working with colleagues at the University of Ulster, both in the UK, have successfully created a new kind of ferroelectric composite material with antimicrobial properties using a novel multi-material three-dimensional (3D) printing process.

According to the engineers, this electrically responsive ferroelectric material can be used to create implants with infection-fighting properties, making them ideal for biomedical applications such as heart valves, stents and bone implants that reduce the risk of infection for patients.

While commonplace, all biomedical implants pose some level of risk as materials often carry surface bio-contaminants that can lead to infection. Reducing this risk could be beneficial both to patients, in the form of improved outcomes, and to healthcare providers, thanks to reduced costs incurred by ongoing treatment.

The engineers had previously used this printing technique to fabricate 3D scaffolds for bone-tissue engineering.

Hamideh Khanbareh, a lecturer in materials and structures in Bath’s Department of Mechanical Engineering, is lead author of a paper on this work in Advanced Materials Technologies. She says this development has scope for wide-ranging applications.

“Biomedical implants that can fight infection or dangerous bacteria such as E. coli could present significant benefits to patients and to healthcare providers. Our research indicates that the ferroelectric composite materials we have created have a great potential as antimicrobial materials and surfaces. This is a potentially game-changing development that we would be keen to develop further through collaboration with medical researchers or healthcare providers.”

The innovation comes thanks to ferroelectricity, a characteristic of certain polar materials that can generate an electrical surface charge in response to a change in mechanical energy or temperature. In ferroelectric films and implants, this electrical charge leads to the formation of free radicals known as reactive oxygen species (ROS), which can selectively eradicate bacteria. This comes about through the micro-electrolysis of water molecules on the surface of the polarized ferroelectric composite material.

This composite material is made by embedding ferroelectric barium calcium zirconate titanate (BCZT) micro-particles in polycaprolactone (PCL), a biodegradable polymer widely used in biomedical applications. The mixture of the ferroelectric particles and polymer is then fed into a 3D bioprinter to fabricate a specific porous ‘scaffold’ shape designed to have a high surface area to promote ROS formation.

Testing showed that even when contaminated with high concentrations of aggressive Escherichia coli bacteria, the composite can completely eradicate the E. coli cells without external intervention, killing 70% of the cells within just 15 minutes.

This story is adapted from material from the University of Bath, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.