Plasma layers for medical technology

Osteoplasts on a hydrophilic (left) and hydrophobic (right) surface of a titanium dental implant.
© Fraunhofer IFAM

Osteoplasts on a hydrophilic (left) and hydrophobic (right) surface of a titanium dental implant.

Cells on a hydrophilic SiOx layer.
© Fraunhofer IFAM

Cells on a hydrophilic SiOx layer.

Cells on a hydrophobic SiOx(CH3)y layer.
© Fraunhofer IFAM

Cells on a hydrophobic SiOx(CH3)y layer.

The Plasma Technology and Surfaces department PLATO at Fraunhofer IFAM works closely with customers to develop functional surfaces and coatings for implants and medical products. These activities are part of Fraunhofer IFAM's business segment Medical Technology.

 

Bioactive plasma-polymer coatings

Coatings are used in a wide variety of ways for implants. These include biocompatible color coding on implants to avoid interchanging or for anti-counterfeiting, bioactive coatings for optimizing the osseointegration, and storage layers for antibiotics. Fraunhofer IFAM has particularly long experience in the area of antimicrobial and non-cytotoxic coatings for implants. In addition, coatings comprising a combination of silver particles and antibiotic coatings have a local synergistic effect on implants for preventative or therapeutic uses. A release of silver nano particles can be excluded. The pure physical process of laser structuring applied to an implant surface after manufacturing can be used to positively influence the osseointegration. Porous regions allow, for example, the vascularization of implants, which is important for tissue growth and secures the implant. Another potential development would, for example, be to coat polymer implants (e.g. PEEK) with titanium or titanium oxide to improve the biocompatibility without changing the roughness of the surface.

The surface of a medical product (contact lenses, membranes) can also be of considerable benefit. Examples include biofunctional surfaces to increase cell adhesion and to prevent the non-specific adsorption of proteins, lipids or bacteria. The change of the surface energy leading to the formation of a thin water film creates a long-term hydrophilicity on the surface of the product. Such a change of the surface energy increases the wettability of the medical product. Similarly, plasma coatings can be applied to alter the haptic properties of surfaces of, for example, prostheses and to mechanically protect medical products (from scratching, abrasion, etc.).

 

Functional surfaces in medicine:

  • Biocompatible, hydrophilic coatings based on Ti, TiO2, and SiO2 that allow excellent growth of cell tissue
  • Biocompatible, hydrophobic coatings based on PDMS that reduce cell adhesion
  • Antimicrobial, non-cytotoxic coatings based on SiO2 and TiO2/Ag
  • Colored, decorative coatings for (local) product labeling and recognition
  • Coatings containing antibiotics for controlled release
  • Protein-repelling, hydrophobic coatings based on polyethylene glycol (PEG)
  • Abrasion-resistant, hydrophilic coating based on SiOxCyHz for polymers, metals, and ceramics
  • Silicon surfaces with modified haptic properties