State banks under the supervision of the department of financial institutions shall be authorized to purchase stock in a small business investment company in the same manner and subject to the same restrictions and limitations as national banks under the Small Business Investment Act of 1958, Public Law 85-699, 85th Congress, second session, 72 Stat. 689 (15 U.S.C. § 661 et seq.), including any amendments thereto hereafter adopted.