More fully integrated Orthopedic implants may soon be possible thanks to research by the BYU Applied Biomechanics Engineering Lab.

Orthopedic implants are an effective way to replace or support damaged bone, but in order for these implants to function properly, they need to begin fusing with the bone. This direct structural and functional connection between living bone and the surface of the implant is called osseointegration.

The BYU Applied Biomechanics Engineering Laboratory, directed by Dr. Anton Bowden, is evaluating osseointegration on a new orthopaedic implant coating developed at BYU: carbon-infiltrated carbon nanotubes (CI-CNT). CI-CNT is a desirable material for this use case because it shares a similar porosity and mechanical stiffness with bone and also resists bacteria and biofilm formation due to its nanotexture, which is very similar to natural nanotextures found on dragonfly and cicada wings.

For this study, a CI-CNT surface modification was applied to stainless steel, a common orthopaedic implant material. In order to test the osseointegration of the carbon-infiltrated carbon nanotubes, the stainless steel was first sterilized using an autoclave and then placed in cell culture with human osteoblasts (bone creation cells). The bone cells and the bone material that they created during the testing were made more easily recognizable by applying fluorescent stains.

Below is a view of the stainless steel imaged with a fluorescent confocal microscope. The blue objects are the bone cells, while the green represents the bone material (osteoid) created by the bone cells.

Plain stainless steel:

(A) surface prior to bone cell culture
(B) surface following bone cell culture

CI-CNT surface-enhanced stainless steel:

This project, which required expertise in biomechanical engineering, biology, and chemistry, was conducted by the BYU team consisting of Jacquelyn Monroe (PhD student), Lucy Bowden (undergraduate student), Sandra Hope (Microbiology and Molecular Biology Professor), (Brian Jensen (Mechanical Engineering Professor), and Anton Bowden (Mechanical Engineering Professor). The results were recently presented at the 66th Annual Meeting of the Orthopaedic Research Society in Phoenix Arizona.