Biomaterials are used in prostheses and medical devices for different purposes. Polymers are the most diverse class of biomaterials. All biomaterials must meet certain criteria and regulatory requirements before they can be qualified for use in medical applications. Biocompatibility is one of the most important requirements. Both nondegradable polymers are designed to degrade in vivo in a controlled manner over a predetermined time. The main mechanism of in vivo degradation of polymers is ‘hydrolytic degradation’, in which enzymes may also play a role (i.e. ‘enzymatic degradation’). Both natural e.g., collagen, and synthetic e.g., poly(alpha-hydroxy) acids, biodegradable polymers are used in biomedical applications. Many of the current polymers and processing techniques need to be improved in order to produce polymers with better performance in biological media. An important trend in related research and development is the synthesis of novel polymers, which would exhibit improved biocompatibility, and be bioresponsive.