The ability of a material to perform the required function in a specific application with an appropriate host response. It is evaluated including not only the material but also its shape, surface condition and location of use.
Japanese name: 生体適合性
Biocompatibility appears in 1 practice question across 1 topic, including Biomaterials.
Field: Biomaterials
Biocompatibility is defined as "the ability of a material to perform with an appropriate host response in a specific application". In the past the emphasis was on not reacting and doing no harm in the body, but as materials that exploit active responses of the body increased, such as ceramics that bond to bone and polymers that are resorbed and replaced by tissue, it came to be judged by whether the desired response occurs for the application. Even the same material faces different requirements inside bone, in contact with blood and on the skin, so biocompatibility is an evaluation of a combination of material and application.
When a material is placed in the body, proteins first adsorb on its surface, and cells respond on top of them. Around bioinert materials a thin fibrous membrane often forms, separating the material from the surrounding tissue. Bioactive materials bond chemically to bone at their surface, and bioresorbable materials gradually degrade and are replaced by tissue. For materials in contact with blood, hemocompatibility, which suppresses platelet adhesion and thrombus formation, is important. Released ions and wear debris can cause inflammation or allergy, so not only the surface but also what is produced by degradation is evaluated.
Biocompatibility is evaluated by combining cytotoxicity tests, in which cells are exposed to the material or its extract, tests for sensitizing (allergic) and irritant reactions, genotoxicity tests, implantation tests in animals and others, and the framework is set out in the international standard for the biological evaluation of medical devices (the ISO 10993 series). Which tests are needed depends on the part of the body contacted and the duration. For implants, mechanical compatibility also matters: too little strength leads to failure, and too much stiffness relative to bone thins the bone by stress shielding. Only when both chemical safety and mechanical properties are in place is biocompatibility achieved for that application.
Answer: B. The ability to perform the required function in a specific application with an appropriate host response
Biocompatibility is not an intrinsic property of a material; it is defined as "the ability of a material to perform with an appropriate host response in a specific application". Alumina and zirconia, which do not react with bone, suit the femoral heads of artificial hip joints, but materials that fill bone defects are actually expected to react, by bonding to bone or by being resorbed and replaced by bone. Because the desirable response differs by application in this way, not reacting at all is not a requirement. And even a material with no toxic elements is not compatible with an application if it is so stiff that it causes stress shielding, if its wear debris causes inflammation, or if it forms thrombi in contact with blood. The shape, surface condition and location of use are evaluated as well.
No. Biocompatibility is an evaluation for each application, so a material that works without problems in bone may form thrombi where it contacts blood. The shape, surface condition, duration of use, wear debris and ion release also affect the outcome, so it must be confirmed for each application.
Not necessarily. Some applications, such as the femoral heads of artificial joints, are best served by no reaction, but bioactive materials that bond to bone work well as bone defect fillers, and materials that are resorbed and disappear work well as sutures. Biocompatibility requires that the response needed in that application occurs.
Because the TiO₂ passive film on its surface is stable in body fluids and gives high corrosion resistance, and because osseointegration, in which bone contacts the surface directly, occurs. Its high specific strength and its lower Young's modulus than stainless steel or Co-Cr alloys are also advantages.
Biocompatibility is not an intrinsic property of a material; it is defined as "the ability of a material to perform with an appropriate host response in a specific application".
Which statement correctly describes the idea of biocompatib…Stress shielding Biodegradable polymer Bone cement Hydroxyapatite Osseointegration Superelasticity β titanium alloy