Foreign-Body Reaction: Chronic inflammation and granuloma formation around irritating foreign bodies.Foreign Bodies: Inanimate objects that become enclosed in the body.Giant Cells, Foreign-Body: Multinucleated cells (fused macrophages), characteristic of granulomatous inflammation, which form around exogenous material in the skin. They are similar in appearance to Langhans giant cells (GIANT CELLS, LANGHANS), but foreign-body giant cells have more abundant chromatin and their nuclei are scattered in an irregular pattern in the cytoplasm.Granuloma, Foreign-Body: Histiocytic, inflammatory response to a foreign body. It consists of modified macrophages with multinucleated giant cells, in this case foreign-body giant cells (GIANT CELLS, FOREIGN-BODY), usually surrounded by lymphocytes.Biocompatible Materials: Synthetic or natural materials, other than DRUGS, that are used to replace or repair any body TISSUES or bodily function.Silicones: A broad family of synthetic organosiloxane polymers containing a repeating silicon-oxygen backbone with organic side groups attached via carbon-silicon bonds. Depending on their structure, they are classified as liquids, gels, and elastomers. (From Merck Index, 12th ed)Eye Foreign Bodies: Inanimate objects that become enclosed in the eye.Acellular Dermis: Remaining tissue from normal DERMIS tissue after the cells are removed.Prostheses and Implants: Artificial substitutes for body parts, and materials inserted into tissue for functional, cosmetic, or therapeutic purposes. Prostheses can be functional, as in the case of artificial arms and legs, or cosmetic, as in the case of an artificial eye. Implants, all surgically inserted or grafted into the body, tend to be used therapeutically. IMPLANTS, EXPERIMENTAL is available for those used experimentally.Absorbable Implants: Implants constructed of materials designed to be absorbed by the body without producing an immune response. They are usually composed of plastics and are frequently used in orthopedics and orthodontics.Implants, Experimental: Artificial substitutes for body parts and materials inserted into organisms during experimental studies.Polyethylene Terephthalates: Polyester polymers formed from terephthalic acid or its esters and ethylene glycol. They can be formed into tapes, films or pulled into fibers that are pressed into meshes or woven into fabrics.Materials Testing: The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.Tissue Engineering: Generating tissue in vitro for clinical applications, such as replacing wounded tissues or impaired organs. The use of TISSUE SCAFFOLDING enables the generation of complex multi-layered tissues and tissue structures.Wound Healing: Restoration of integrity to traumatized tissue.Eye Injuries, Penetrating: Deeply perforating or puncturing type intraocular injuries.Macrophages: The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)Foreign-Body Migration: Migration of a foreign body from its original location to some other location in the body.Wounds, Penetrating: Wounds caused by objects penetrating the skin.