<unk> s are used in: # Joint replacements # Bone plates # Intraocular lenses (IOLs) for eye surgery # Bone cement # Artificial ligaments and tendons # Dental implants for tooth fixation # Blood vessel prostheses # Heart valves # Skin repair devices (artificial tissue) # Cochlear replacements # Contact lenses # Breast implants # Drug delivery mechanisms # Sustainable materials # Vascular grafts # Stents # Nerve conduits # Surgical sutures, clips, and staples for wound closure # Pins and screws for fracture stabilisation # Surgical mesh<unk> s 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,<unk> s are usually subjected to the same requirements as those undergone 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. Bone grafts Calcium sulfate (its α- and β-hemihydrates) is a well known biocompatible material that is widely used as a bone graft substitute in dentistry or as its binder. Heart valves In the United States, 49% of the 250,000 valve replacement procedures performed annually involve a mechanical valve implant. The most widely used valve is a bileaflet disc heart valve or St. Jude valve. The mechanics involve two semicircular discs moving back and forth, with both allowing the flow of blood as well as the ability to form a seal against backflow. The valve is coated with pyrolytic carbon and secured to the surrounding tissue with a mesh of woven fabric called Dacron (du Pont's trade name for polyethylene terephthalate). The mesh allows for the body's tissue to grow, while incorporating the valve. Skin repair Most of the time, "Artificial’ tissue" is grown from the patient’s own cells. However, when the damage is so extreme that it is impossible to use the patient's own cells, artificial tissue cells are grown. The difficulty is in finding a scaffold that the cells can grow and organize on. The characteristics of the scaffold must be that it is biocompatible, cells can adhere to the scaffold, mechanically strong and biodegradable. One successful scaffold is a copolymer of lactic acid and glycolic acid.
Biomaterial
Biological agent
Biopharmaceutical
Cathartic
Inhalant
Chemical substance
Toxicant
Nutrient