Plasma Coatings: How to Add a Bactericidal Effect on Parts

Effective antibacterial coatings and treatments have long been an attractive feature sought by manufacturers of all kinds of products, from textiles to medical devices. As bacterial infections continue to be a major health concern around the world, antibacterial coatings for high-touch products such as doorknobs, handrails, touchscreens and other consumer goods are becoming a must-have product feature. However, efficient coatings and the technologies to successfully apply them have been a challenge.

This is especially true for medical devices such as implants, where antibacterial coatings are a key element in strategies to prevent bacterial colonization and biofilm formation that can negatively impact device performance and patient safety. Device-associated infections may cause severe problems connected with long-term antibiotic treatment, implant failure, and even death.

What is a Bactericidal Coating?

A bactericidal, or antibacterial, coating is a microscopically-thin layer containing bacteria-fighting compounds that is deposited on a surface. There are two kinds of bactericidal coatings:

• Passive, which can hinder bacterial attachment to a surface or kill bacteria on contact.
• Active, which releases antibacterial agents, such as antibiotics, bioactive molecules, and inorganic antimicrobial agents to the surrounding tissue.

Advances in plasma-based technology have made it a suitable and versatile solution for engineering and applying antibacterial coatings to a wide variety of materials at a low temperature without any need of specific substrate or any chemical solvents. The plasma-assisted approach enables very specific surface modifications by grafting chemical functionalities, or by depositing nanometer-thick coatings with high antibacterial efficiency. Among different antibacterial agents applied using plasma-based methods, 5–200 nm nanoparticles of metals and oxides have been found to be very effective against bacteria and microorganisms.

Adding a bactericidal coating to products offers a number of benefits, including:

• Diminishing the rate at which bacteria grows and killing any bacteria currently on the surface
• Unlike a disinfectant spray, these coatings do not have to be reapplied
• The coatings cannot be seen or felt so they do not affect user experience
• The coatings are not smearable or transferable to other surfaces with which they come into contact

Plasma Treatment: Game-Changing Technology for Medical Devices

Many of today’s implantable medical devices are manufactured using metals such as steel, titanium alloy, cobalt chrome, magnesium-based alloys, as well as tantalum, nitinol, and platinum-based alloys, to name a few. As implant use increases, the incidence of implant-associated infection (IAI), a serious complication, is also on the rise.

Fortunately, plasma technology presents one of the most compelling ways to improve metal’s antibacterial activity; plasma treatment can significantly alter metal surfaces’ physicochemical properties, such as surface chemistry, roughness, wettability, surface charge, and crystallinity, which all play an important role in the biological response of medical materials. Plasma surface modification techniques are proving to be an effective way to prepare antibacterial surfaces, not only for better adhesion of antibacterial coatings but also for inducing the formation of antibacterial effects of metal implants.

Using Plasma Deposition to Apply Bactericidal Coatings

Despite the considerable health benefits associated with bactericidal coatings, applying them to surfaces is no different than applying any other coating using vacuum-based plasma technology. The surface is first cleaned and activated in the vacuum chamber to provide optimal bonding performance of the coating. Once the product has been properly cleaned and activated, a monomer such as AgNO3 is added to the chamber – silver (Ag) is a highly popular antimicrobial agent used in a wide variety of applications and materials.

After the part is treated, the vacuum chamber is purged of the process gases and vented to enable the removal of the product using strict industrial hygiene protocols to ensure sterility. Plasma technology’s environmentally-friendly process and the ability to operate the system remotely reduces both worker and patient risk.

Plasma-enhanced chemical vapor deposition is a flexible, scalable, efficient, and effective method for applying bactericidal coatings to a wide range of consumer and healthcare products. Whether it’s dozens, hundreds, or thousands of parts, plasma technology is a fast, cost-effective tool for adding value and safety to almost any product.

Learn how manufactures are leveraging plasma treatment by downloading the eBook, "The Manufacturer's Plasma Coating Playbook." If you are interested in speaking to an expert in plasma applications, please consider reaching out and scheduling a plasma treatment overview discussion.