Nanotechnology Could Make a New Generation of Orthopedic Devices Available

Nanoscale oxidative patterning of biocompatible metallic surfaces could lead to superior medical implants that could allow the human body to better accept orthopedic, dental, and cardiovascular metal prostheses.

Researchers at the Université de Montréal (QC, Canada), Plasmionique (Brossard, QC, Canada), the Universidade de São Paulo (Brazil), and other institutions capitalized on recent advances in nanotechnology to change how metals modulate cell activity and development in the body. A critical aspect of the finding is that the metallic surfaces can directly stimulate cells, thereby eliminating the need for pharmaceuticals and their deleterious resulting side effects. The researchers applied chemical compounds to modify the surface of the common biomedical metals--such as titanium--by exposing them to selected etching mixtures of acids and oxidants, which resulted in surfaces with a sponge-like pattern of nano (ultrasmall) pits.

The researchers then tested the effects of the chemically produced nanoporous titanium surfaces on cell growth and development. They showed that the treated surfaces increased growth of bone cells, decreased growth of unwanted cells, and stimulated stem cells, relative to untreated smooth metal surfaces. In addition, expression of genes required for cell adhesion and growth were increased in contact with the nanoporous surfaces. The new technique was described in the January 2009 issue of Nano Letters.

"Using chemical modification, we have produced metals with intelligent surfaces that positively interact with cells and help control the biological healing response,” said senior author Antonio Nanci, Ph.D., a professor at the Université de Montréal's faculty of dentistry. "These will be the building-blocks of new and improved metal implants that are expected to significantly affect the success of orthopedic, dental and cardiovascular prostheses.”

"Our study is groundbreaking,” added Dr. Nanci. "We use simple yet very efficient chemical treatments to alter metals commonly used in the operating room. This innovative approach may ultimately hold the key to developing intelligent materials that are not only easily accepted by the human body but that can actively respond to the surrounding biological environment.”

Related Links:
Université de Montréal
Plasmionique
Universidade de São Paulo