A double-structured tissue implant and a method for preparation and use thereof for implantation into tissue defects. The double-structured tissue implant comprising a primary scaffold and a secondary scaffold consisting of a soluble collagen solution in combination with a non-ionic surfactant generated and positioned within the primary scaffold. A stand alone secondary scaffold implant or unit. A process for preparation of the double-structured implant or the stand alone secondary scaffold comprising lyophilization and dehydrothermal treatment.