Any bonds issued by the authority may be used by the holders thereof as security for deposits of any funds belonging to the state or to any instrumentality, agency or political subdivision of the state in any instance where security for such deposits may be required or permitted by law. Any surplus in any state fund and any retirement or trust fund, where the investment thereof is permitted or required by law, may be invested in bonds issued by the authority. Unless otherwise directed by the court having jurisdiction thereof, or the document that is the source of authority, a trustee, executor, administrator, guardian, or one acting in any other fiduciary capacity may, in addition to any other investment powers conferred by law and with the exercise of reasonable business prudence, invest trust funds in the bonds of the authority.