a porous implant matrix consists mainly of a mixture of polymers which are differently rapidly degradable , wherein nominal resorption times of two of the components of the mixture , each accounting for at least 10 % of the mixture , differ by a factor of at least 5 . the porous implant matrix is manufactured from a mixture of the at least two differently rapidly degradable polymers , wherein particles of both polymers are mixed with particles of a water - soluble solid and a solvent for one of the polymers , and after evaporating the solvent is optionally compacted , and the solid is removed by watering .