A Bottom-Up Approach Grafts Collagen Fibrils Perpendicularly to Titanium Surfaces
mediaposted on 28.08.2020, 15:39 by Eloise P. Miller, Jonathan K. Pokorski, Leena Palomo, Steven J. Eppell
Currently, titanium dental implant apposition to bone is achieved via osseointegration leading to ankylosis. A biomimetic Sharpey’s fiber-type interface could be constructed around collagen fibrils robustly attached and projecting perpendicularly from the titanium surface. We present a proof-of-concept for a method to create upright-standing collagen nanofibrils covalently bonded to a titanium surface. The method involves activation of the titanium surface using a plasma discharge treatment followed by functionalization with an oxyamine-terminated silane coupling molecule. Using Rapoport’s salt, the N-termini of individual type I collagen monomers are converted to ketones. When presented to the functionalized titanium surface, these ketones form oxime linkages with the silanes thus immobilizing the collagen. In a two-step process, these covalently bonded monomers act as sites for the formation of fibrils. Many fibril–surface junctions were observed by scanning electron microscopy on three different surfaces. These findings set the stage for working toward a high surface density of such features which might act as a platform from which to build a synthetic ligament.