AFM Force Mapping of Proteins to Improve Bioceramic Implant Fixation

Shutterstock | Denis Simonov

The city of Limoges, located in the heart of west central France, is known for its high quality porcelain factories which employed up to 10,000 workers at the height of their golden age during the second half of the 19th century.

Coming back to the present day, a team of researchers at the University of Limoges are exploring other, more modern and innovative kinds of ceramic material, called bioceramics.

The group is part of the "Science of ceramic processing and surface treatments" laboratory* which examines materials and applications relative to the health, energy, and information technology sectors.

Bioceramics are an important subset of biomaterials. They are particularly useful in the repair and reconstruction of bone.

Dr Chantal Damia, Member of the Research Group

bioceramics research

The team’s main focus is on the development of devices based on calcium phosphate bioceramics for applications in bone tissue engineering. The composition of these materials is close to the mineral part of bones and therefore they exhibit osteoconductive properties (i.e. they allow bone in growth into porous implants).

The development of advanced bioceramics for bone remodeling requires better knowledge of their interactions with the biological environment (i.e. the bone cells and proteins involved in cell adhesion). The team have recently been working on setting up characterization tools to monitor the interactions.

This research is particularly useful for improving the efficiency of medical devices like bone substitutes. It also opens up possibilities for extending their use to large bone defects (>20 cm2) for which natural bone regeneration only occurs at the peripheral region between the bone and the substitute.

AFM Force Mapping of Protein on Calcium Phosphate Bioceramics

One current focus is the impact of bioceramic surface topography and composition on protein adhesion forces. The team investigated this using a technique known as atomic force spectroscopy coupled with PicoImage data analysis software (based on Mountains® technology).

They chose to concentrate on one protein in particular, fibronectin (Fn), which promotes cell adhesion allowing the differentiation and survival of osteoblasts (cells involved in the process of bone formation).

To measure the adhesive force between fibronectin and bioceramic material, the protein was grafted onto the cantilever tip of our Keysight atomic force microscope (AFM). This tip was put into contact with a calcium phosphate bioceramic substrate made from silicated hydroxyapatite powder synthesized by an aqueous precipitation method.

Once contact between the functionalized tip and the substrate was obtained, the cantilever was removed and the adhesive force of fibronectin measured. Force mapping was performed with spectroscopy mode in air. Results of the study are soon to be published.

Download Digital Surf's Magazine for More Stories

Force Curve Analysis Tools Used in this Study

Interactive Parameter Maps

The force value is measured for each surface point at the adhesion event cursor (a histogram of values can be displayed). Force values are shown in a parameter map.

Two cursors were generated on the parameter map (right) in order to show and compare individual force curves in neighboring zones.

This is an interactive feature: the displayed force curve is updated when the cursor is moved.

Interactive Parameter Maps

Multilayer 3D View

Force value was applied as texture to the sample topography. In the resulting 3D model, the granular structure of the surface can be clearly observed (the bioceramic material is acquired from a powder).

Multilayer 3D View

* Research unit operated by the University of Limoges in association with the French National Center for Scientific Research (UMR CNRS 7315).

Digital Surf.

This information has been sourced, reviewed and adapted from materials provided by Digital Surf.

For more information on this source, please visit Digital Surf.

Ask A Question

Do you have a question you'd like to ask regarding this article?

Leave your feedback
Submit