Bonds issued by authority under the provisions of sections 136A.15 to 136A.178 are hereby made securities in which all public officers and public bodies of the state and its political subdivisions, all insurance companies, trust companies, banking associations, investment companies, executors, administrators, trustees and other fiduciaries may properly and legally invest funds, including capital in their control or belonging to them; it being the purpose of this section to authorize the investment in such bonds of all sinking, insurance, retirement, compensation, pension and trust funds, whether owned or controlled by private or public persons or officers; provided, however, that nothing contained in this section may be construed as relieving any person, firm, or corporation from any duty of exercising due care in selecting securities for purchase or investment; and provided further, that in no event shall assets of pension funds of public employees of the state of Minnesota or any of its agencies, board or subdivisions, whether publicly or privately administered, be invested in bonds issued under the provisions of sections 136A.15 to 136A.178. Such bonds are hereby constituted “authorized securities” within the meaning and for the purposes of section 50.14. Such bonds are hereby made securities which may properly and legally be deposited with and received by any state or municipal officer or any agency or political subdivision of the state for any purpose for which the deposit of bonds or obligations of the state now or may hereafter be authorized by law.