This Act being designed to effect a public use and purpose, the corporate authorities of the municipal corporation or corporations creating the Public Building Commission and the corporate authorities of any other municipal corporations which may be desirous of renting space in any building or buildings to be acquired or constructed by such Public Building Commission, may make donations of property, real or personal, or cash grants to the Public Building Commission in such amount or amounts as they may deem proper and appropriate in aiding the Public Building Commission to effectuate the purpose for its creation.