Biomaterial

Introduction

The development of biomaterials is not a new area of science, existing for around half a century, it’s study is named Biomaterial Science. It is an exciting field of science, experiencing steady and strong growth over its history with companies such as Smith and Nephew investing large amounts of money in new products. Biomaterials science encompasses elements of medicine, biology, chemistry and materials science.

Definition of a Biomaterial

Williams, in 1987, defined a biomaterial as:

    A biomaterial is a nonviable material used in a medical device, intended to interact with biological systems

A biomaterial is essentially a material that is used and adapted for a medical application. Biomaterials can have a benign function, such as being used for a heart valve, or may be bioactive and used for a more interactive purpose such as hydroxy-appetite coated hip implants (the Furlong Hip, by Joint Replacement Instrumentation Ltd, Sheffield is one such example – such implants are lasting upwards of twenty years). Biomaterials are also used every day in dental applications, surgery, and drug delivery (a construct with impregnated pharmaceutical products can be placed into the body which can give a prolonged release of a drug over an extended period of time).

The definition of a biomaterial does not just include man-made materials which are constructed of metals or ceramics. A biomaterial can also be an autographic, allographic or xenographic transplant material.

Biomaterial Applications

Biomaterials are used in:

• Joint replacements
• Bone plates
• Bone cement
• Artificial ligaments and tendons
• Dental implants for tooth fixation
• Blood vessel prostheses
• Heart valves
• Skin repair devices
• Cochlear replacements
• Contact lenses

Biomaterials must be compatible with the body, and there are often issues of biocompatibility which must be resolved before a product can be placed on the market and used in a clinical setting. Because of this, biomaterials are usually subjected to the same requirements of those suffered by new drug therapies. All manufacturing companies are also required to ensure traceability of all of their products so that if a defective product is discovered, others in the same batch may be traced.

Subjects integral to biomaterials science

• Toxicology

 A material should not be toxic, unless specifically engineered to be so (for example “smart” drug delivery systems that target cancer cells and destroy them).

• Biocompatibility

 Biocompatibility is difficult to measure, it is defined in terms of success at a specific task.

• Functional Tissue structure and pathobiology

 Understanding of the anatomy and physiology of the action site is essential for a biomaterial to be effective.

• Healing

 Healing is an essential consideration when using biomaterials. The body may experience what is known as a foreign-body reaction after implementation so immuno-suppression may be required.

• Dependence on Specific anatomical sites of implantation

 It is important, during design, to ensure that the implement will fit complimentary and have a beneficial effect with the specific anatomical area of action.

• Mechanical and Performance requirements

 Biomaterials that have a mechanical operation must perform to certain standards and be able to cope with pressures. It is therefore essential that all biomaterials are well designed and are tested. Biomaterials that are used with a mecanical application, such as hip implants, are usually designed using CAD (Computer Aided Design)which allows all of the directional stresses to be calculated, ensuring maximum product life.

• Industrial involvement

 Companies and researchers push the boundaries and development of science in general, and biomaterials is no exception.

• Ethics

 Ethical considerations are paramount – as are legal considerations and compliance with the law.

• Regulation

 As mentioned above, regulation and records are required to be kept by the product manufacturer for much longer than the product life.

Biomaterial may also refer to:

• Biological matter
• Biocompatible material and bioapplicable material
• Biologically derived material (or biotic material)
• Bio-based material

Biological material:

Main disambiguation page: Biological material

Biological material may refer to:

Natural materials

• Organic matter, matter that has come from a once-living organism, or is composed of organic compounds
• A chemical substance present or produced in a living organism
  • Biomolecule, a molecule present in a living organism
  • Biogenic substance, a chemical substance produced by a living organism
  • Biotic material, natural material, or natural product, a material produced by a living organism
• Biomass, living or dead biological matter, often plants grown as fuel
• Biomass (ecology), the total mass of living matter in a given environment, or of a given species
• Body fluid, any liquid originating from inside the bodies of living people
• Cellular component, material and substances of which cells (and thus living organisms) are composed
• Tissue (biology), a cellular organizational level intermediate between cells and a complete organ
• Viable material, capable of living, developing, or germinating under favorable conditions (see Viability selection)

Human-made materials

• Bio-based material, a processed biotic material
• Biocomposite, a composite material formed by a matrix (resin) and a reinforcement of natural fibers
• Biomaterial, any substance that has been engineered to interact with biological systems for a medical purpose