The book offers a short introduction into the field of biomaterials, focusing on their requirements for specific applications and classification according to their nature. Next supercritical fluids are described as green alternatives to the solvents and plasticizers traditionally employed for biomaterial processing. Supercritical fluids (especially supercritical carbon dioxide) have been used successfully for particle production, microcellular foaming, impregnation, solvent extraction and material drying.