U of T researchers discover new ways to build better medical implants and improve healing time

Khosravi, Davies and DaCosta

PhD candidate Niloufar Khosravi, Princess Margaret Cancer Centre scientist Dr. Ralph DaCosta and Professor John Davies are members of a research team that have uncovered new information about medical devices that could accelerate post-surgical healing. (Photo: Luke Ng / University of Toronto).

June 18, 2018 | By Luke Ng

A University of Toronto research team has uncovered new information that could accelerate post-surgical healing for procedures involving medical devices as diverse as dental implants and skin dressings.

Their paper, published in Nature Communications Biology today, describes how different implant surface textures affect a fundamental process in the body’s ability to heal the area surrounding the implant.

“We have known for decades that creating nano-scale implant surface texture improves clinical success rates,” said John E. Davies, a professor in U of T’s Faculty of Dentistry and Institute of Biomaterials & Biomedical Engineering (IBBME)—the senior author of this study. “However, little was known of the cellular mechanisms by which the implant surface affects the healing process.”

The team, co-led by Princess Margaret Cancer Centre scientist Dr. Ralph DaCosta, looked at the effect of implant surface texture on neovascularization—the process of blood vessel formation— around implants.

“The ability for blood vessels to form around an implant is a key factor in its successful tissue integration,” said Niloufar Khosravi, a PhD candidate in Davies’ lab and the study’s first author. “Indeed, neovascularization is vital for tissue healing and regeneration around the implant.”

Implant surface with blood vessels

Blood vessels (green) forming on a nano-surfaced titanium implant (grey) as visualized by intravital microscopy using the team’s model. (Image: Niloufar Khosravi).

To study this effect, the team built a model that allowed them to observe the implant healing process in real time using intravital optical microscopic imaging systems developed in DaCosta’s lab. Their experiments monitored the formation of new blood vessels around a series of medical-grade titanium implants at the cellular level, and how the distribution and pattern of neovascularization changed in the presence of implants of differing surface texture.

“We did not initially expect blood vessels to be clearly visible in this model,” said Khosravi. “We decided to add an imaging contrast agent after a few pilot studies and the resulting resolution was remarkably higher than we expected. It allowed us to monitor not only the rate, but also the location, shape, function and pattern of new blood vessels around implants over a six week period.”

Niloufar Khosravi

Doctoral researcher Niloufar Khosravi (right) was awarded for the presentation of her research at the 2018 Canadian Biomaterials Society annual meeting in Victoria, BC earlier this year. (Photo: Niloufar Khosravi).

In addition to adding new knowledge for designing better medical implants, the team’s findings could also address other related challenges in human health.

“We can use this knowledge to build broader implantable biomaterials to improve the quality of life for people who have impaired healing conditions, such as the elderly or persons with diabetes,” said DaCosta, who is also an assistant professor in U of T’s Department of Medical Biophysics. “We now have new tools and strategies to better support the body’s natural repair process.”