Processing and characterization of cellular metals from Ti-based alloys for osseo regeneration

• Grant number: 11/24108-0
• Support Opportunities: Regular Research Grants
• Duration: May 01, 2012 - April 30, 2014
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Carlos Roberto Grandini
• Grantee: Carlos Roberto Grandini
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil

Abstract

The increase in human life expectancy has resulted in an equal demand for metallic biomaterials. As one gets older, there is a natural wear and tear on the body and organs. These losses can be verified in vision, hearing, nervous, respiratory and cardiac systems; bones; joints or even in tumor growth in any part of the body; among other problems. Nor should one ignore the injury occasioned by the practice of sports (whether considered radical or not), traffic accidents, street weapons and firearms. The bone is one of the few human tissues that have the ability to regenerate alone, provided that the defect has certain limits. Healing undue bone can have large consequences, such as the loss of some motor functions. One attempt to rehabilitate the lost tissue entails the replacement of bone tissue through the use of permanent orthopedic implants, processed from metals, ceramics, polymers and composites. Various materials have been tested, with the goal of applying them as substitutes or bone regenerators; however, the vast majority of materials used for these purposes are bioceramics such as hydroxyapatite, alumina, zirconia, calcium phosphate, glass, etc. These materials are biodegradable, bioinert and bioactive, but inconvenient in that they lack mechanical properties appropriate for biomedical applications in great mechanical efforts. The alternative to this "problem" of ceramics is the use of metallic materials. Thus, many efforts are made to develop material with biological characteristics compatible with ceramics and displaying the mechanical resistance of metals. In addition to the biological aspects, researchers also consider the porous aspect of ceramics, which is one of the factors that stimulate bone growth. Pores with sizes ranging from 100 µm-200 µm enable growth of osteoblasts above and inside the pores, leading to formation of osteroides that mineralize inside or outside of bone implant. Micropores on the walls of macropores are important for effective fixation of cells and implant. Therefore, researchers today turn to the development of porous metal materials (cellular metals). Cellular metals are characterized by large amounts of empty space inside, delimited by metallic walls. This arrangement provides a combination of properties quite peculiar, such as low density, resulting in the high stiffness and high-energy absorption capacity. The use of such material is growing and is in various fields, such as the chemical industry, thermal and acoustic insulation, construction (coating of floors, walls and separator environments) and the aeronautics industry (for manufacture of structural panels). (AU)