S.C. Code Ann. § 11-43-320

The bank may pledge any of its revenue or funds to the payment of its bonds, subject only to any prior agreements with the holders of particular bonds which may have pledged specific money or revenue. Bonds may be secured by a pledge of any loan obligation owned by the bank, any grant, contribution, or guaranty from the United States, the State, or any corporation, association, institution, or person, any other property or assets of the bank, or a pledge of any money, income, or revenue of the bank from any source.