The bonds shall bear the manual or facsimile signatures of such authority commissioner or officer as may be designated in the resolution authorizing the bonds and such signatures shall be the valid and binding signatures of such commissioner or officer, notwithstanding that before the delivery thereof and payment therefor any or all of the persons whose signatures appear thereon have ceased to be commissioner or officer of the authority. The validity of the bonds shall not be dependent on, nor affected by, the validity or regularity of any proceedings relating to any mortgage loans or housing projects for which the bonds are issued. The resolution authorizing the bonds may provide that the bonds shall contain a recital that they are issued pursuant to this chapter and the recital shall be conclusive evidence of their validity and of the regularity of their issuance. Bonds issued pursuant to this chapter are fully negotiable.