Synthetic multi-layer structures comprising biopolymer fibres

A method for the in vitro preparation of a synthetic multi-layer structure comprising biopolymer fibers, wherein the biopolymer fibers in each layer are unidirectionally and uniformly oriented, which comprises:

• a) positioning a holder comprising a layer of a biopolymer fiber forming solution in a magnetic field and inducing fiber formation, in order to obtain fibers which are unidirectionally and uniformly oriented in the layer,
• b) introducing a further layer of the biopolymer fiber forming solution in the holder, said further layer being introduced over the layer obtained in step a), and
• c) positioning the holder in the magnetic field and inducing fiber formation, in order to obtain fibers which are unidirectionally and uniformly oriented in said further layer,
• thus obtaining a synthetic multi-layer structure,
• wherein the fiber orientation in at least one layer differs from that in at least one of its superior and/or inferior layer according to an angle alpha, and wherein said differential orientation results from changing by a rotation according to the angle alpha the position of the holder of step c) relative to the position of the holder of step a).