A process for the manufacture of a collagenous material from a plurality of collagen particles is described. The collagen particles are derived from a natural tissue material, are substantially free of non-fibrous tissue proteins, cellular elements and lipids or lipid residues, and comprise fragments of collagen fibres displaying original collagen fibre architecture and molecular ultrastructure of the natural tissue material. The process comprises the step of freeze drying the collagen particles in suspension in a freeze-drying suspension medium.
