Purchase this article with an account.
J.P. McAllister, J. Li, K. Deren, P.G. Finlayson, C. Jaboro, G.A. Auner, R. Baird, A. Lagman, R. Iezzi, G.W. Abrams; Chronic in vivo biocompatibility testing of materials used for visual prostheses . Invest. Ophthalmol. Vis. Sci. 2004;45(13):4214.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose:To comprehensively evaluate the short– and long–term biocompatibility of novel and traditional biomaterials that could be used in a neural prosthesis. Methods: Circular "wafers" (2.5 x 0.250mm) of aluminum nitride, sapphire, platinum, and Corning borosilicate glass were implanted onto the cortical surface of adult rats. The bone flap was replaced and animals allowed to survive 10, 28 or 90 days. Normal, sham–operated and mechanically–lesioned animals served as controls. Tissue underlying each implant was processed for light microscopy using Nissl staining, silver staining for degenerating axons and neurons, and immunohistochemistry for reactive astrocytes and microglia. Quantitative assessments for cellular damage and glial reactivity were performed using a 3–point rating scale. Results:No animals developed neurological symptoms or infections, and wafers did not migrate from the original implantatin site. Sham operations and implants of coverslip glass and sapphire did not show marked effects. In contrast, aluminum nitride caused significant axonal degeneration in the cortical laminae and subcortical white matter, and a slight astrocytic reaction in the same regions. These changes, as well as glial reactivity to coverslip glass, were also elevated compared to intact controls, and occurred within 10 days of implantation. Conclusions: These preliminary results suggest that aluminum nitride, a possible semiconductor material for new devices, may not be compatible with neural tissue over protracted periods.
This PDF is available to Subscribers Only