摘要 |
<p>A procedure for the manufacture of a structured multilayer membrane, suitable for use in surgical reconstructions of ligament, bone or cartilage tissue, the membrane being made of collagen I freed from telopeptides (partly at least) and containing a minimum of one barrier-structure layer closed to cell ingrowth and one sponge-like structure layer open to cell ingrowth, the procedure consisting of steps where a collagen suspension is frozen in a flat bed into plates which are then vacuum-dried at a temperature below their thawing temperature, the sponge-like membranes are wetted by a controlled procedure in which a limited amount of water, smaller than as sufficient for hydration of the whole membrane thickness, is applied to them, the wetted membrane is conveniently allowed to rest at a reduced temperature of 0°C to 10°C for the moisture to equilibrate inside the structure, the thickness is modified as appropriate by applying mechanical pressure, one side is conveniently discriminated from the other by applying a tread pattern or dye, the membrane is re-frozen and dried at a reduced pressure, controlled heating being applied during a later stage of the drying procedure for the moisture temperature to rise to above the thawing temperature. The invention also covers the membrane so obtained and its use.</p> |