Body implants

In the electronics industry. Pis find wide appHcations as a dielectric material for semiconductors due to thermal stabiHty (up to 400°C) and low dielectric constant. Pis are being considered for use in bearings, gears, seals, and prosthetic human joints. The intended part can be machined or molded from the PI, or a film of PI can be appHed to a metallic part. Because of their superior adhesion, dielectric integrity, processing compatibUity, and lack of biological system impact. Pis have been used in many biological appHcations with particular success as body implants. 

Silicone mbbers have been widely used for medical applications, particularly for body implants in structural cosmetic surgery. One high-profile application has been that of breast implants, but the award in early 1994 of enormous damages by a US court in respect of faulty implants may discourage development of this application. 

Materials used in body implants must meet several essential requirements such as tissue compatibility, enzymatic and hydrolytic stability. They must also be chemically resistant and have good mechanical properties. They must not be toxic, or the surrounding tissue will die. They must be resistant to the body fluids which usually have a high percentage of chloride ions. They must be biologically active if an interfacial bond is to be achieved. In some cases, they must be able to withstand continued high mechanical stresses for many years. 

This polymer is used to make body implants needed for only a short time. Eventually the polymer is converted back to lactic acid, which is metabolized to CO2 and water in the same manner as natural lactic acid. Thus, the body absorbs the polymer without leaving any permanent residue. Draw at least four repeat units of the stracture of the polymer made from lactic acid. 

Over the past several decades, there has been some concern over the potential hazards and safety of the cosmetic use of silicone body implants—breast implants, in particular. Several manufactures have been sued over the failure of the implants, and the federal government... 

Diverse applications blood transfusion tubing, antibiotic container closures, domestic refrigerators, non-adhesive rubber-covered rollers for handling different materials, potting and encapsulation, medical applications (particularly for body implants). 

Titanium alloys have also become popular in body implants, such as artificial hips and knees. These alloys are light, strong, long-lasting, and biocompatible. Biocompatible means that the alloy does not cause a reaction when placed into the body. 

Use Capacitors, chemical equipment, dental and surgical instruments, rectifiers, vacuum tubes, furnace components, high-speed tools, catalyst, getter alloys, sutures and body implants, electronic circuitry, thin-film components. 

There is no established evidence (epidemiological or experimental) for carcinogenicity caused by exposure to Cr(III) or Cr(0) compounds (113, 117). However, allergic contact dermatitis due to occupational exposure to Cr(lll) (primarily in the leather tanning industry) is relatively common (144—146). The safety of oral intake of Cr(III) in food supplements has also been questioned (Section IV.D) (5). A concern about the safety of the use of Cr(0) in stainless steel body implants (e.g., artificial joints or fracture fixation plates) was raised following at least one reported case of bone cancer caused by corrosion of the implant (147). In vitro studies have shown that the corrosion of Cr alloys in human semm leads to Cr(III) binding to serum proteins (148). Such corrosion can also release another possible carcinogen, Ni(II) (149). This problem should be overcome by the use of Ti alloys (free of Cr or Ni), which were introduced as an alternative 10-15 years ago (150). 

This section focuses on prominent medical applications where 3D textile strucmre has been applied, that is, bandages and composite dressings for wound management and supportive structures for tissue engineering and body implants. 

It is obvious that there are a number of vast challenges to overcome when using 3D artificial textile stmctures as a base for producing body implants to replace damaged or diseased body tissues such as skin, blood vessels, cartilage, ligaments, tendons or bones to recover and maintain physiological function. 

Different types of stents are common examples of body implants. A stent is a woven, knitted or braided cylindrical mesh structure made of stainless steel, nitrol or chrome-cobalt alloy that is inserted in a diseased or contracted artery or vein to restore a free blood flow by keeping the vessel open. The stent can be coated with substances to obtain specific properties or for continuous release (a drug-eluting stent) to inhibit cellular growth that may lead to repeated occlusion. 

The use of body implants for, for example, vascular grafting and tissue engineering may have even greater future potential as new methods and materials for body implants are presented. However, the rapid development in 3D printing and... 

Stmctural feamres of fibrous implantable devices have been smdied to point out parameters that enhanced biointegration. Although structural features have considerable impact on the expected biological response to foreign body implantation, it s... 

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