Documents / Report
This Defense Intelligence Agency reference document, dated 7 January 2010 and prepared under the Acquisition Threat Support series, surveys biomaterials used in medicine. It covers biocompatibility, biosensor membranes, silicones, Teflon, biodegradable polymers, hydrogels, titanium, bioceramics, tissue constructs, cardiovascular stents, contact lenses, drug delivery and dialysis. It concludes that biomaterial performance underlies many medical devices, that the industry is slow to adopt new materials because of testing costs, and that innovation mainly involves new applications of established materials.
“metallic”13 pages
UNCLASSIFIED/,Sf8R 8ffl81slals W61i 8fJb'J composed of long-chain molecules crosslinked to one another to create many small empty spaces that can absorb water or other liquids like a sponge. Hydrogels can be extruded into nearly any shape. Figure 14 shows them as small dots. If the spaces are filled with a drug, the hydrogel can dispense the drug gradually as the structure biodegrades. Hydrogels are also used for tissue engineering and tissue repair, where the spaces in the gel might be filled with stem cefls, tissue-growth factors, or a combination of the two. Hydrogels are cross-linked polymer networks that are insoluble in body fluids but are able to swell and often have a water content of up to 90 percent. These can be formed by crosslinking one or several types of monomer units into a network, forming a homopolymer, copolymer, or multipolymer. With the incorporation of different monomers, gels with wide-ranging chemical and physical properties can be formed. The gels can be neutral or charged, soft or stiff, strong or brittle. Hydrogels are routinely used for biomedical and pharmaceutical applications such as drug release, artificial tendons, wound-healing bioadhesives, artificial kidney membranes, artificial skin, and contact lenses. TITANIUM - HIP AND KNEE JOINTS Titanium-based hip and knee implants are quite successful and are among the most common orthopedic procedures. When a hip replacement is performed, the arthritic, damaged hip joint is removed. The ball-and-socket hip joint is then replaced with an artificial implant. Hip implants often show no visible sign of their existence in either walking gait or functionality. In adults, they can last a lifetime. Knee implants are also known to be successfu I. Figure 15 shows an assortment of titanium t1ip joint assemblies. The long shaft part of the dev1ce fills a drilled hole in the long bone of the femur. BIOCERAMICS Ceramic materials are sometimes used directly or modified for use in applications in the human body and, so, become known as bioceramics. • Figure 15. Various Titanium Components Used in Hip Joint Replacement The most common applications are in bone repair, dentistry, and the use of ceramics in hip and knee joint replacements, where their exceptional hardness can be put to advantage in wear joints. Biaceramics range in biocompatibility from the ceramic oxides, which are inert in the body, to the other extreme of resorbable materials, which are eventually replaced by the materials they were used to repair. 11 UNCLASSIFil:D/J'f8N: 8ffl&ili1l1k W&lii 8tlla¥
Not linked to a story yet.
Report, from the dia collection. The PDF is mirrored here; the original link is under it. 32 pages are in the text index: search them above, or from the library's search.