By polymers for biological use we understand biopolymers and living matter. Biomaterials are man-made or -modified materials which repair, reinforce or replace damaged functional parts of the (human) body. Hip joints, cardiovascular tubes or skin adhesives are just a few examples. Such materials are principally chosen for their mechanical performance (stiffness, strength, fatigue resistance). All mechanical and biological interactions between an implant and the body occur across the interface, which has to correspond as nearly as possible to its particular function.A natural surface is a complex (three-dimensional) structure, which has to fulfil many roles: recognition, adhesion (or rejection), transport or growth. We have to admit that at present biomaterials are far removed from such performance although new strategies in surface engineering have been adopted in which man tries to learn from nature.