Bacteria-fighting materials

Billions of dollars are spent each year fighting what sometimes seems like a losing battle against infections in hospitals and medical facilities. However, many materials have bacteria-fighting abilities that can contribute significantly to the health of our surroundings. Here, we look more closely at some industry-leading antimicrobial materials and ideas that are helping to transform the relationship between human health and the designed environment.

When bacteria attach to a surface they form communities of bacteria called biofilms. These biofilm communities find their strength in numbers, becoming very resistant to being cleared by the human immune system. Around 80% of microbial infections in the body result from biofilms. However, hard and soft materials as well as coatings and films are all able to prevent biofilms from attaching to their surfaces in a number of ways – from passively preventing the accumulation of biofilms to actively and aggressively killing them. Below, we feature selected antibacterial materials from Materia´s collection and discuss how these materials are able to combat bacteria and disease while offering inspiring visual and tactile material qualities for healing environments. We also discuss the recent discovery of a new class of materials that could lead to an exciting new generation of antibacterial products.

Hard materials

Many hard materials gain their antimicrobial properties from smooth, non-porous surfaces that limit the ability of bacteria to permeate a material´s exterior. With no voids for bacteria to hide in, the surfaces of such materials can be easily cleaned of any biofilms that manage to develop. Cristalite is an example. Composed of 85% quartz and 15% acrylic, Cristalite has a smooth surface similar to that of polished granite however it is 30 times more hygienic than granite due to its non-porous nature. Silestone Volanco is approximately 90% quartz and similarly non-porous but its subtle, molten-rock texture gives it a matte finish that feels softer to the touch without compromising its antibacterial properties.

By contrast, Bios.Antibacterial Ceramics gain their antibacterial properties through the use of an active bactericide. During the processing stages, proprietary mineral particles that generate a highly effective antibacterial reaction are added to this ceramic material. The resulting ceramic tile may be supplied in natural, polished or glazed versions since the antibacterial particles are embedded in the core of the tile.

Polluted and cement print offers yet another strategy for combating bacteria through the use of photo catalytic technology. Light-sensitive photo catalytic white cement or paint is screen printed to create ´invisible´ motifs that become visible over time as pollutants discolour the area of the surface not protected by paint. The nanotech white paint is able to break down organic polluted molecules and bacteria in the air and transform them into harmless substances. The material itself becomes the decoration, suggesting and showing its tactility and textured features.

Soft materials

The antibacterial properties of silver have been known to cultures all around the world for many centuries. Ancient Phoenicians for instance stored water and other liquids in silver coated bottles to discourage contamination by bacteria. Recently, manufacturers have taken advantage of silver´s bacteria killing abilities by incorporating silver particles in their products. AgUARDIAN for instance encapsulates silver ions within the .001mm skin of its antimicrobial polyurethane fabrics. The silver ions are able to kill 99.9% of all harmful micro-organisms that come in contact with the surface of the material. This includes not only bacteria but also viruses, fungi-mould, and mildew.

Felix, Fillipa and Florentijn Bio also make use of silver to produce a range of soft to the touch, coloured fabrics that are made of 100% TreviraCS and have special bioactive properties. The textile consists of a minimum of 50% bioactive yarns with silver nanoparticles integrated into their fibres. The silver ions break down cell membranes and prevent bacteria from forming.

Coatings and films

Copper, like silver, is also an effective agent for killing bacteria. Antimicrobial copper is a family of copper alloys ideally suited for use wherever it is important to minimise bacterial levels on touch surfaces such as handles, hand rails, door hardware and countertops – particularly in facilities where microbial contamination on surfaces is a threat to public health. These copper alloys are able to kill 99.9% of the bacteria that come in contact with their surfaces within two hours. They are also versatile materials to work with as they can easily be polished to almost any desired texture and shaped to a desired form and dimension by any of the common forming processes.

Sharklet is a film for application to surfaces that takes a completely different strategy to bacteria. Inspired by the microbe-resistant properties of shark skin, it is purely the material´s pattern that works to inhibit micro organism growth – there are no biocides or toxins involved. Laboratory tests show that Sharklet´s micro-pattern disrupts the microbial colonising processes that are necessary for bacteria to develop into a disease-causing biofilm. The patterned surface has demonstrated an ability to reduce bacterial growth by 80% versus an untreated surface.

Future directions

A new group of materials recently unveiled by University of Nottingham scientists could be applied as coatings that work in a new way – by preventing the attachment of bacteria to the surface of a material in the first instance. The idea is that bacteria ´dislike´ these materials and will not attach to them. Instead, bacteria are left swimming in a planktonic state, unable to form damaging biofilms. The immune system can then clear bacteria as it would do if there was no surface to form a biofilm on. Bacteria are left with literally no surface to stand on. Compared to commercially available coatings, these new material coatings are able to reduce the numbers of bacteria present on a surface by up to 96.7%. Furthermore, by preventing the attachment of bacteria to materials rather than killing them, there is also a hope that these new materials will hinder the antibiotic resistance of bacteria. The next challenge is to have these new materials recognised and further developed by designers, manufacturers and the medical industry.

To date, the interaction between bacteria such as E. Coli and materials has not been fully understood. As such, there is significant potential in investigating the connection between human health and materials. This season, Materia is exploring how innovative materials can make a different to our health in an exhibition called ’The Healing Environment’. New and innovative materials such as those featured above as well as in our exhibition and our online materials collection have the potential to make a huge difference in the way our environment allows us to heal and remain healthy.