N.C. Gen. Stat. § 116-183

The Board is hereby authorized, subject to the approval of the Director of the Budget, to accept grants of money or materials or property of any kind for any project from a federal agency, private agency, corporation or individual, upon such terms and conditions as such federal agency, private agency, corporation or individual may impose. The bonds issued under this Article are exempt from all State, county, and municipal taxation or assessment, direct or indirect, general or special, whether imposed for the purpose of general revenue or otherwise, excluding income taxes on the gain from the transfer of the bonds and notes, and franchise taxes. The interest on the bonds and notes is not subject to taxation as income.