Using animal tissues as starting materials, a method is described for producing extracellular matrix particulates. The invention includes an embodiment wherein the matrix particulates are applied to collagen scaffolds, which can be seeded with living cells or the particulates may alone be seeded with living cells. Further, the invention encompasses bonding the particulates to collagen foams, or collagen threads made into fabrics or to foams combined with threads. The particulates, with or without scaffolding, can be used as tissues for grafting or as model systems for research and testing. The invention also encompasses the spinning of threads on which the matrix particulates are components and the freeze drying of foams to whose surfaces the matrix particulates are attached.