Transparent nanocrystalline yttria-stabilized-zirconia calvarium prosthesis

Laser-based diagnostics and therapeutics show promise for many neurological disorders. However, the poor transparency of cranial bone (calvaria) limits the spatial resolution and interaction depth that can be achieved, thus constraining opportunity in this regard. Herein, we report preliminary results from efforts seeking to address this limitation through use of novel transparent cranial implants made from nanocrystalline yttria-stabilized zirconia (nc-YSZ). Using optical coherence tomography (OCT) imaging of underlying brain in an acute murine model, we show that signal strength is improved when imaging through nc-YSZ implants relative to native cranium. As such, this provides initial evidence supporting the feasibility of nc-YSZ as a transparent cranial implant material. Furthermore, it represents a crucial first step towards realization of an innovative new concept we are developing, which seeks to eventually provide a clinically-viable means for optically accessing the brain, on-demand, over large areas, and on a chronically-recurring basis, without need for repeated craniectomies.From the Clinical EditorIn this study, transparent nanocrystalline yttria-stabilized-zirconia is used as an experimental “cranium prosthesis” material, enabling the replacement of segments of cranial bone with a material that allows for optical access to the brain on a recurrent basis using optical imaging methods such as OCT.

Graphical AbstractTransparent cranial implants could serve as a critical enabler for laser-based diagnosis and treatment of many neurological disorders. However, the intrinsic brittleness of transparent implants reported thus far predisposes them to catastrophic fracture-based failure, thus limiting opportunity for clinical translation. Novel nanocrystalline transparent implants are reported herein that seek to address this limitation through use of zirconia, a tough ceramic with well-proven biocompatibility in other chronic implantation applications.Figure optionsDownload high-quality image (89 K)Download as PowerPoint slide