Biomedical Engineering Theory And Practice/Biomaterials

Rehabilitation Engineering Oncology Introduction The United States National Institute of Health Consensus Development Conference defined a biomaterial as ‘‘Any substance (other than a drug) or combination of substances, synthetic or natural in origin, which can be used for any period of time, as a whole or as a part of a system which treats, augments, or replaces any tissue, organ, or function of the body’’ (Boretos and Eden, 1984)Boretos, J.W., Eden, M. Contemporary Biomaterials, Material and Host Response, Clinical Applications, New Technology and Legal Aspects. Noyes Publications, Park Ridge, NJ (1984), pp. 232–233.. Biomaterials area has grown over for 50 years. Biomaterils as a field uses ideas from medicine, biology, chemistry, materials science and engineering. In addition, biomaterials researchers should consider ethics,law and the health care delivery system. Biomaterials can be divided into metals, ceramics, polymers, glasses, carbons, and composite materials. Table 1 shows a few applications for synthetic materials in the body. It contains many materials that are often classified as “biomaterials.” Metals, ceramics, polymers, glasses, carbons, and composite materials are listed in this table. Such materials are used as molded or machined parts, coatings, fibers, films, foams,fabrics, liquid and powder. Table 2 presents the size of the commercial market for biomaterials and medical devices.The global biomaterial market would reach $88.4 billion by 2017 from $44.0 billion in 2012. The biomaterial market grows continually and globally because of increased investiments, funding and grant by government, active collaboration, technology advancement, increasing application of biomaterials and growing number of elderly people. Table 1. Types of Biomaterials, characteristics and applications Biomaterials Science: An Introduction to Materials in Medicine Buddy D. Ratner, Allan S. Hoffman, Frederick J. Schoen, Jack E. November 8, 2012 Academic Press 978-0123746269 2J. B. Park, Biomaterials Science and Engineering, Plenum Press, New York,1984.K. Mattox, Biomaterials- Hard Tissue Repair and Replacement, vol. 3 (D. Muster,Editor), Elsevier, Amsterdam, 1992.J.E.Lemons Perspectives on Biomaterials, Materials Science Monographs. No 33 (O. C. Lin and E. Y. S.Alejandro Sáenz, Eric Rivera-Muñoz, Witold Brostow and Victor M. Castaño,CERAMIC BIOMATERIALS: AN INTRODUCTORY OVERVIEW, Journal of Materials Education Vol.21 (5-6): 297 - 306 (1999) Material Advantages Disadvantages Main Applications Polymers: Silastic, Teflon, Dacron, Nylon, PMMA, Polyethylene, Polypropylene, Polytetrefluorethylene Easy to produce, low density Low mechanical resistance, easily degradable Sutures, arteries, veins, cements, artificial tendons, teeth, ears, nose, heart valves, lenses, testicles and breasts. implants Metals: Steels 316, 316L, Vitallium, Silver, Tantalum Cobalt F-75 and alloys of: Ti, Cr+CO, Cr+Co+Mo Ductility, high mechanical resistance to wear and shock Low biocompatibility, corrosion in a physiological environment, mechanical properties very different from those of biological tissues Staples, plaques and wires, articulation prosthesis, tooth implants, penis implants, skull plaques and mesh for face reconstruction Ceramics: Aluminum oxides, calcium aluminates, titanium oxides, calcium phosphates, carbon, Bioglass High biocompatibility, corrosion resistance, high resistance to compression, inert, low thermal and electrical conductivity Low impact resistance, properties difficult to reproduce, difficulties in processing and fabrication Dental parts, coatings, bone fillings, endoscopy, otologic implants, medical tools and equipment Composites: Metals with ceramic coatings, materials coated with carbon High biocompatibility, corrosion resistant, inert Lack of consistency and difficult to reproduce during fabrication Heart valves, knee implants, artificial articulations, hip implants Natural Materials: Collagen, human tissues, hialuronic acid, grafts Availability in the human body, biocompatibility Possible rejection by host Increase or substitution of hard and soft tissues, cornea protectors, vascular grafts, tendons and ligaments, heart valves, phthalmologic lubricants, substitution of synovial fluid Table 2. Biomaterials and Healthcare market Total US health expenditures $2.9 trillion (2013)Centers for Disease Control and Prevention Total U.S. medical device market $110 billion(2014)SELECTUSA,The Medical Device Industry in the United States The global market for biomaterials $44.0 billion(2012)Custom Market Research Services,Biomaterials Further Reading The Biomedical Engineering Handbook, Third Edition Bronzino, Joseph D. April 2006 [CRC Press] 978-0-8493-2124-5 http://crcpress.com/product/isbn/9780849321245 Biomed: From the Student's Perspective, First Edition Villafane, Carlos, CBET. June 2009 [Techniciansfriend.com] 978-1-61539-663-4 http://www.biomedtechnicians.com Biomaterials Science: An Introduction to Materials in Medicine Buddy D. Ratner, Allan S. Hoffman, Frederick J. Schoen, Jack E. November 8, 2012 Academic Press 978-0123746269 Practise Reference A Brief review: Biomaterials and their application, Amogh Tathe et al,Int J Pharm Pharm Sci, Vol 2, Suppl 4, 19­23 Biomaterials by Joon B. Park, Roderic S. Lakes