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This Defense Intelligence Reference Document, dated 7 January 2010, was prepared by the Defense Intelligence Agency's Defense Warning Office. It is one of a series of advanced technology reports produced in FY 2009 under the Advanced Aerospace Weapon System Applications program. The report reviews biomaterials used in medicine, including silicones, Teflon, biodegradable polymers, hydrogels, titanium, ceramics and tissue constructs, and applications such as stents, joints, contact lenses, drug delivery and dialysis. It concludes that most innovation lies in new ways to apply existing materials.
From the source: Release of 2026-09-18 Incident: 1/7/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD is a broad survey of biomaterials, including metals, polymers, ceramics, glasses, and composites designed to interact with living tissue, and argues that their value depends mainly on biocompatibility, reliability, and careful matching of material properties to specific medical uses. The report reviews major application areas including biosensors, implants, cardiovascular devices, contact lenses, drug delivery systems, tissue constructs, titanium devices, and dialysis membranes, emphasizing that no single biomaterial works best in every setting. Its overall conclusion is that biomaterials are already foundational to a large medical-device industry and save or improve millions of lives, but that progress tends to be slow because safety testing is stringent; as a result, most advances come from improved ways of applying established materials such as silicone, Teflon, biodegradable polymers, ceramics, and titanium in new devices and clinical settings rather than from radically new substances.
UNCLASSIFIED// FOR 8FFl@IAk Uili ON! X one free from concerns of immunogenicity . These polymers can be optically clear, exhibit good flexibility, and have strength comparable to that of many plastics. BIODEGRADATION ADVANTAGES In the human body, biodegradable polymers have good compatibility but also decompose to harmless materials and over time dissolve altogether. Biodegradable polymers undergo a chemical hydrolysis in the salty and wet environment of tissues by way of a labile chemical backbone of the polymer. The degradation starts immediately upon water exposure and occurs in two steps. In the first step, the material t horoughly hydrates, and the water attacks the polymer chains, converting long chains into shorter, water-soluble fragments. The desirable aspect of this process is a reduction in molecular weight without a loss in physical properties, since the device matrix is still held together, even with the shorter chains. In the second step, the shorter polymer chains are attacked by enzymes that are naturally present in tissues. Basically, a metabolization of the fragments by the body tissues results in a rapid loss of polymer mass, what is referred to as bulk erosion. All the commercially available synthetic devices and sutures degrade by bulk erosion. DEGRADABLE BIOMATERIALS Different biodegradable polymers have different lifetimes in tissues, ranging from a few days to years . Combining two different biopolymers-for example, short-lived (days) PLA (polylactide) and longer lived (months) PGA (polyglycolide)-reveals that polymers can be produced with intermediate decomposition times. Thus, their decay times can be custom determined through their formulation. Biodegradable polymers fulfill a physician's desire to have an implanted device that will not require a second surgical intervention for removal, which is desirable in many applications. In orthopedic applications, for example, a fractured bone that has been fixated with a rigid, nonbiodegradable stainless implant has a tendency for refracture upon removal of the implant, making removal undesirable. This refracturing results from the offloading of the stress on the bone by the stainless steel support because the bone has not carried a sufficient load during the healing process. However, a fixation system prepared from a biodegradable polymer can be engineered to degrade at a rate that will slowly transfer the load to the healing bone, thereby avoiding the risk of refracture and eliminating the need to remove the impla nt. POLYLACTIC ACID AND POLYGLYCOLIC ACID Polylactic acid (PLA), polyglycolic acid (PGA), and their copolymers are the most widely used of the biodegradable polymers. These materials, when exposed to the sun and weather, will degrade into water and carbon dioxide and essentially vanish, given sufficient time. In the human body, combinations of PLA and PGA are used to control the longevity of a material by controlling its degradation rate when exposed to tissues. The degradation products in the human body are also water and carbon dioxide. UNCLASSIFIED//EOR OSSICIAk WSE 8HL'I 8
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Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 32 pages are in the text index: search them above, or from the library's search.