Biodegradable polymers and composites in biomedical applications: from catgut to tissue engineering - Part 1 - Available systems and their properties

Biodegradable polymers form a unique class of materials that created an entirely new concept when originally proposed as biomaterials. That is, for the first time, a material performing a structural application was designed to be completely resorbed and to become weaker over time. This concept was first applied successfully with catgut sutures and later, with more arguable results, on bone fixation plates and pins. Current research on new and improved biodegradable polymers is focused on more sophisticated biomedical applications to solve patients' problems with higher efficacy and the least possible pain. One example is tissue engineering, in which a biodegradable scaffold seeded with an appropriate cell type provides a substitute for damaged human tissue while the natural process of regeneration is completed. An overview is given of the degradation properties and mechanisms of biodegradable polymers, their processability and biocompatibility, focusing on the aspects most relevant to biomedical applications. The main families of biodegradable polymeric systems are described and the systems that are commercially available or that are currently being studied and proposed for specific medical applications are reviewed.