No member of the board or employee of a land bank shall acquire any interest, direct or indirect, in real property of the land bank, in any real property to be acquired by the land bank, or in any real property to be acquired from the land bank. No member of the board or employee of a land bank shall have any interest, direct or indirect, in any contract or proposed contract for materials or services to be furnished or used by a land bank. The board may adopt supplemental rules and regulations addressing potential conflicts of interest and ethical guidelines for members of the board and land bank employees.