Bio-Materials:

“Bio-materials are defined as synthetic materials that can be implanted in the body to provide special prosthetic functions or used in diagnostic, surgical and therapeutic applications without causing adverse effect on blood and other tissues”

    Bio-materials have been developed from among metals, ceramics and polymers.

Metallic Bio-materials:

    Metals are used as bio-materials due to their excellent electrical and thermal conductivity and mechanical properties. Since some electrons are independent in metal, they can quickly transfer an electric charge and thermal energy. The mobile free electrons act as the binding force to hold the positive metal ions together, this attraction is strong, as evidenced by the closely packed atomic arrangement resulting in high specify gravity and high melting points of most metals.

    Since the metallic bond is essentially non-directional, the positions of the metal ions can be altered without destroying the crystal structure resulting in a plastically deformable solid.

Uses:

    Some metals are used as passive substitutes for hard tissue replacement such as total hip and knee joints, for fracture healing aids as bone plates and screws, spinal fixations devices, and dental implants because of their excellent mechanical properties and corrosion resistance. Some metallic alloys are used for more active roles in devices such as vascular stents, catheter guide wires, orthodontic arch wires and cochlea implants.

Ceramic Bio-materials:

    Ceramic which are used as bio-materials are classified as bioceramics, the relative inertness to the body fluids, high compressive strength, and aesthetically pleasing appearance led to the use of ceramics in density as dental crown. Some carbons have found use as implants especially for blood interfacing applications such as heart valves.

    Due to high specific strength as fibers and their biocompatibility, ceramics are also being uses as reinforcing components of composite implant materials and for tensile loading applications such as artificial tendon and ligaments.

Medical applications of polymeric biomaterials:

Polyvinyl chloride:

    Blood and solution bag, surgical packaging, IV sets, dialysis devices, catheter bottles, connectors, and cannulae.

Polyethylene:

    Pharmaceutical bottle, nonwoven fabric, catheter, pouch, flexible container, and orthopaedic implants.

Poly propylene:

    Disposable syringes and reservoirs, membrane for blood dialyzer, implantable ocular lens and bone cement.

Polysterene:

    Tissue culture flasks, roller bottles, and filter waves.

Polyethylenter phthalate:

        Implantable suture, mesh, artificial vascular grafts and heat valve.

Polytetra fluoroethylene:

    Catheter and artificial vascular grafts.

Polyurethane:

    Packaging film, catheters, sutures and mould parts.