HARRICK PLASMA

Plasma Treatment to Improve Functionality of Biomaterials

Biomaterials are typically chosen for their chemical inertness and low surface energies. However, these properties can also make it difficult to effectively apply functional coatings and facilitate desirable interactions with other surfaces. This article discusses the benefits of plasma treating biomaterials in order to further enhance their functionality as well as gives example applications and plasma treatment processing guidelines.

For references citing the use of our plasma cleaners in biomaterials applications, see the Biology, Biomedical Applications, and Cleaning and Sterilization categories in the References: Technical Articles page.

Benefits of Plasma Treatment of Biomaterials

Plasma treatment modifies the surface wetting properties, which can ultimately enhance the functionality and biocompatibility of biomaterial surfaces. Plasma introduces oxygen-containing functional groups to increase surface hydrophilicity of biomaterials without affecting their bulk material properties. This improves the adhesion of subsequent coatings or adsorption of other functional groups. Oxygen plasma also has the added benefit of simultaneously cleaning and sterilizing biomaterial surfaces in laboratory research settings.

Example Applications

Plasma treatment can be applied to a wide variety of materials as well as complex surface geometries. Below are example biomedical applications and samples that have been treated in our plasma instruments:

  • Treat fibrous polymer scaffolds to increase surface hydrophilicity and enhance cell adhesion, coverage, and proliferation for tissue engineering
  • Facilitate bonding of polydimethylsiloxane (PDMS) microfluidic devices fabricated for cell culturing
  • Activate sapphire surface to promote adhesion of heparin coating and improve biocompatibility as an implant material
  • Alter surface chemistry of PDMS to promote adsorption of polyethylene glycol (PEG) as an anti-biofouling coating
  • Treat ultra-high molecular weight polyethylene (UHMWPE) to increase surface hydrophilicity and promote protein adsorption, which can act as a lubricant and reduce friction in artificial joints
  • Clean and activate microelectrode arrays (MEAs) for the fabrication of biosensors
  • Sterilize titanium implant materials, stainless steel, and fibrous polymer scaffolds

Processing Guidelines

Air or oxygen (O2) gas is typically used for plasma cleaning and sterilization. An air or O2 plasma removes organic contaminants by chemical reaction with highly reactive oxygen radicals and ablation by energetic oxygen ions. The plasma also introduces oxygen-containing functional groups (hydroxyl, carboxyl) on the surface, rendering the surface more hydrophilic and increasing surface wettability.

Alternatively, an argon plasma may be used for cleaning. Argon plasma cleans by ion bombardment and physical ablation of contaminants off the surface. In some cases, a mixture of Ar/O2 has been applied for plasma sterilization, as it was found that the addition of oxygen was more effective in destroying microorganisms than Ar plasma alone [1].

[1] Moisan, Michel, Jean Barbeau, Marie-Charlotte Crevier, Jacques Pelletier, Nicolas Philip, and Bachir Saoudi. "Plasma sterilization. Methods and mechanisms." Pure Appl. Chem. (2002) 74(3): 349-358.

The process conditions for treating biomaterials vary widely as plasma treatment can be applied to many different biomedical applications and materials. Consult with Harrick Plasma on your specific application for further processing guidelines and technical references.