We may soon have new weapons in the fight against microscopic pathogens. Researchers at Battelle are developing advanced materials with antimicrobial properties that could help prevent the spread of diseases.
The need for new antimicrobial options is especially urgent in healthcare settings, where hospital-acquired infections still affect 1.7 million people and contribute to as many as 99,000 deaths annually, according to the CDC. But interest in antimicrobials stretches far beyond the clinic. Antimicrobial agents have made their way into consumer products including soaps, mouthwashes and cleaning supplies, and are increasingly found in clothing, carpets and other household products.
Most antimicrobial products rely on chemical biocides. While these options can be effective and are generally considered to be safe, there is growing concern among consumers and healthcare providers about potential unintended consequences of long-term use. Chemicals in soaps and other products lack specificity to particular microbes of interest, can accumulate in the environment, and may accelerate the evolution of antibiotic-resistant bacteria. In addition, these products do not keep surfaces sterile for an extended period of time; surfaces have to be continually rewashed with the biocides in order to keep microbes from accumulating.
For these reasons, interest is growing in materials with inherent antimicrobial properties. Integrating antimicrobial materials into hospital surfaces and equipment could help to reduce the risk of hospital-acquired infections. Schools, commercial and government buildings, and other public gathering places could also benefit from materials that slow the spread of colds, influenza and other pathogens. Building antimicrobial properties directly into materials would offer longer-lasting protection from microbe build up and avoid many of the potential unintended consequences of chemical biocides.
Battelle researchers are working to make antimicrobial materials a reality. The Battelle initiative, called “Surfaces by Design,” focuses on engineering materials (hard surfaces, coatings, and gels) to meet specific application needs, including antimicrobial characteristics. Some of the most promising areas include:
- Antimicrobial Surfaces: Biocidal or biostatic materials have antimicrobial properties that either damage microbes directly or prevent adhesion to the surface. For example, copper, silver and cationic substances are biocidal—they actually damage the cell walls of microbes—while superhydrophobic surfaces and some nanostructured surfaces mechanically interfere with the cell walls of bacteria that try to adhere. Battelle’s approach is to ‘tether’ biocidal and biostatic chemicals to a substrate to offer extended protection and avoid leeching of biocidal chemicals into the environment.
- Heated Coatings: Heat offers another promising avenue for antimicrobial materials. Heat can quickly kill microbes. Battelle has developed a conductive coating called HeatCoat™ that can be rapidly heated with the application of a small amount of electricity. Originally developed for anti-icing applications in the aviation industry, conductive coatings could be used to kill microbes on hard-to-clean hospital surfaces.
- Stimuli Responsive Materials: Stimuli responsive materials use a dynamic approach to inhibit targeted bacteria. These materials actively detect the presence of a microbe and generate a response such as the release of a biocidal agent. Unlike biostatic materials, stimuli responsive materials can be targeted to specific bacteria such as E. coli. The stimulus response in the material may depend on specific proteins on the bacterial cell wall to trigger a reaction in the material that neutralizes the pathogen.
Antimicrobial materials could be used in a wide range of products such as surgical implements, hospital scrubs, medical devices, computer keyboards, and walls and floors in sterile areas. Different applications will call for different antimicrobial approaches. Battelle researchers are working to design smart surfaces, coatings, gels and other materials that incorporate effective and application-appropriate antimicrobial properties.