A University of Toronto team from the Institute of Biomaterials and Biomedical Engineering (IBBME) discovered that nano-scale surface topology matters when it comes to vascularization of bone implants. They compared two titanium implants of the same chemical composition and varied only their surfaces at the nano scale. One was smooth and the other was rough and nano-patterned.
In their experiments of bone regrowth around a skull implant, they observed over three times more bone formation around the implant with a rough surface. To uncover the mechanism, they turned to intravital microscopy to visualize the implant at microvessel scale in real time in a live mouse. Here, the team discovered that at 42 days post implantation, the rougher implant had faster new blood vessel growth with bigger and more branched vessel networks.
As neovascularization is a prerequisite for new bone growth, it’s likely that this enhanced blood vessel growth and maturation is responsible for the integration of bone. Quicker access to better vessels can promote tissue growth by bringing in more nutrients, bringing out degradation products, and recruiting immune cells that help with remodeling. The question of why exactly the blood vessels form better on rougher nano-scale surfaces at a biomolecular scale still remains an intriguing question.
“We have known for decades that creating nano-scale implant surface texture improves clinical success rates,” said John E. Davies, senior author of the study in an interview with IBBME. “However, little was known of the cellular mechanisms by which the implant surface affects the healing process.”
This finding is directly relevant to fields including orthopedic surgery, dentistry, and plastic surgery, providing insight into why their textured implants perform better. More broadly, these findings suggest a pathway to success for other tissue engineering constructs for diseases that require high vascularization, such as islet implantation for diabetes treatment.
Open access study in Nature Communications Biology: Nanosurfaces modulate the mechanism of peri-implant endosseous healing by regulating neovascular morphogenesis…
Via: U of T…