Surface Nanocoatings for Porous Implant Materials

By AZoNano.com Staff Writers

Topics Covered

Introduction
Coating of Porous Implant Materials
Preserved Porosity and Surface Topology
Enhanced Wettability
Retained Material Flexibility
Improved Bone Growth
Conclusion
About Promimic AB

Introduction

The advent of new implant materials has completely transformed the implant industry. These materials facilitate interpenetration and formation of blood vessels, which are vital for bone growth, and mimic the function, structure and physiology of trabecular bone. These materials can hence enhance the integration of implants.

Coating of Porous Implant Materials

The primary component of hard structures in the bone is hydroxyapatite (HA). In the implant industry, HA has long been used as a coating material. The HAnano Surface is an exclusive HA coating which measures just 20 nm. This effective and unique coating procedure can easily be used for surface coating of any type of structure. In fact, porous materials made of e.g. PEEK, tantalum and titanium can be coated with the HAnano Surface. The coating is based on a wet chemical process producing a nanometer thin layer of HA.

Figure 1. Porous titanium implant

Preserved Porosity and Surface Topology

The coating method preserves the underlying surface structure even for porous structures having a specific surface topology. When the HAnano Surface is applied, an even layer of HA crystals cover the entire surface of the structure. The coating technique enables the material to be coated over the entire surface without  affecting the porosity or  the surface topology.

Figure 2. Porosity and surface topology of the coated material

The above figures clearly demonstrate that the surface topology and porosity of the coated material is maintained, which is not possible with thicker HA coatings.

Enhanced Wettability

The wetting behavior of a material is crucial for porous structures with tiny pore sizes, because the capillary action becomes more dominant as the size of the pores reduces. In order for body fluids to absorb into small cavities and pores, it is important to have a hydrophilic surface.

The images shown below depict a wetting experiment with HAnano Surface coated material and unmodified porous material. The material’s wettability is transformed from hydrophobic to hydrophilic after the application of the HAnano Surface coating.

Figure 3. Unmodified porous material and HAnano Surface coated material.

Retained Material Flexibility

Porous materials generally exhibit low modulus of elasticity, which is similar to that of cancellous bone. As the HAnano Surface measures only 20 nm and follows the underlying structure suitably, the material’s flexibility is retained. In addition, the material can easily flex without causing any flaking or cracking of the coating.

Improved Bone Growth

When a porous implant is coated, it produces an implant that resembles human bone, both in terms of chemical structure and shape. Bone growth can be improved through the combination of the HAnano Surface and a porous structure, thus producing highly advanced porous implants.

Conclusion

The application of HAnano Surface coating on porous materials produces a material that exhibits chemistry and structure comparable to bone and produces an osteoconductive surface. Furthermore, due to the unique coating technology in combination with a 20 nm thin layer of HA, coating with the HAnano Surface preserves the porosity as well as retains the material’s flexibility. In addition, presence of the HAnano Surface creates a super-hydrophilic surface which is of importance for porous structures. .

About Promimic AB

Promimic is a biomaterial company founded in 2004 as a spin-off from research performed at Chalmers University of Technology in Gothenburg, Sweden. The company develops and markets a new generation of implant surface modifications and synthetic bone based on a patented method for production of nano sized hydroxyapatite. Promimic has an innovative and experienced organization that continuously is working on new ways to improve surface modification and coating of new materials.

  • HAnano Surface is a unique implant surface which dramatically accelerates osseointegration. The surface can be applied onto various types of materials - including metals, ceramics and polymers - regardless of its dimensions and structure. The HAnano Surface has received 510(k) approval by the FDA (American Food and Drug Administration), which applies to the area of dental implants.
  • HAnano Bone is a new generation of synthetic bone. The unique composition of HAnano Bone allows it to be mouldable over extended periods of time.

This information has been sourced, reviewed and adapted from materials provided by Promimic AB.

For more information on this source, please visit Promimic AB.

Date Added: Aug 29, 2013 | Updated: Sep 5, 2013
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