The present invention pertains to the development of Extracellular Matrix (ECM) scaffolds derived from the forestomach of a ruminant. Such scaffolds are useful in many clinical and therapeutic applications, including wound repair, tissue regeneration, and breast reconstruction. In addition, the present invention features methods of isolating ECM scaffolds from mammalian organs, including but not limited to the ruminant forestomach. The invention further features laminated ECM scaffolds containing a polymer positioned between individual ECM sheets. The polymer may optionally contain bioactive molecules to enhance the functionality of the scaffold.