Applications of Polymers in Medicine

An abbreviated list of medical applications for commodity polymers (Table 13.6) is an indication of the wide scope of both materials and their uses. Since many of these uses require small volumes of premium materials, it is often feasible to supplement commodity plastics by developing specialty polymers that would not otherwise be justified on an economic basis. In the examples that follow, one encounters both commodity polymers such as ultrahigh-molecular-weight polyethylene (UHMWPE) and poly(tetrafluoroethylene) (PTFE), and specialty polymers such as the polyanhydrides and poly(glycolic acid). 

Tubing and bags for blood, urine, and infusion solutions Contact lenses 

Hip joint prostheses Vascular grafts (blood vessel) 

polystyrene, polycarbonate, polyester Polypropylene, polystyrene PVC, LDPE, polyurethanes 

PMMA (hard), poly(hydroxyethyl acrylate) (soft) 

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An important application of polymers in medicine is in advanced drug-delivery systems. These materials control the drug concentration and delivery rate in the body. Hyperbranched polyesters have been suggested for such systems [111]. However, most applications within this field, described in the literature, deal with dendrimers and not with hyperbranched polymers. 

The long quest for blood-compatible materials to some extent overshadows the vast number of other applications of polymers in medicine. Development and testing of biocompatible materials have in fact been pursued by a significant number of chemical engineers in collaboration with physicians, with incremental but no revolutionary results to date. Progress is certainly evident, however the Jarvik-7 artificial heart is largely built from polymers [34]. Much attention has been focused on new classes of materials, such... 

In this chapter, several classes of biopolymers are discussed. First, biobased and biodegradable polymers are considered, together with wood plastic composites (WPCs) (Section 8.2). A field of increasing importance is the application of polymers in medicine, particularly their use in the human body (Section 8.3). 

There are other applications of polymers in medicine, such as membranes for blood purification or separation of blood components, medical disposal (syringes, catheters, blood bags, sanitary products), dental fillings, resorbable bone nails, drug delivery systems, hydrogels, and different products for clinical diagnostics. 

An idea of the range of materials and applications for polymers in medicine can be gained from the information in Table 10.1. As can be seen from this table a number of polymers are used in medical applications. One particular such polymer is poly (methyl methacrylate), PMMA. Early on it was used as the material for fabricating dentures later other biomedical applications developed. For example, PMMA is now used as the cement in the majority of hip replacement operations worldwide. 

The application of nanosilver in medicine is particularly an important issue. The method of production of nanosilver-coated polymers, which are used as plastic catheters, has been developed. A coating with silver nanoparticies acts as an antibacterial and disinfectant. The in vitro tests confirmed growth inhibition in the bacterial layer which was sustained for 72 h (Roe et al., 2008). In patent... 

The use of polymers in medicine is steadily growing. The synthetic and processing flexibility of polymers continue to permit polymers to be applied in a broad range of medical, biological, and implant applications. Creative polymer synthesis continues to expand the functionality and tunability of polymers for medical applications. There are now excellent biomedical polymers available to address general needs in medidne (the subject of this chapter). Opportunities that present themselves for enhanced or improved biomedical polymers are in the following areas ... 

In conclusion we note that there are a wide variety of current applications of pol3rmers in medicine and that much research is in progress. While essentially all of these applications still need improvement, these biomedical applications of polymers are helping to alleviate human suffering and future advances will aid in achieving this goal more fully. 

The most prominent aliphatic polyamides are polyamide 6 and polyamide 6.6. Polyamides are used in a broad range of applications as performance polymers in medicine, textile, and car manufacturing industries. In 2003, the European production ofpolyamides was approximately 3 million tons for technical applications. Of the total polyamide consumption, 94% was polyamide 6 and polyamide 6.6. 

Medicine. There are many applications of PEI in the medical sector. Analytical methods, such as the quantitative determination of the surface charge of serum lipoproteins (442), are aided by use of PEI, and it is also used as a carrier in the development of polymer drugs (443,444). 

FIGURE 7.31 Release of hydroxyethyltheophylline in water from a PEO slab (Mw = 0.6 x 106). [Graph reconstructed from data by Apicella et al. in Polymers in Medicine Biomedical and Pharmaceutical Applications, R. M. Ottenbrite and E.M.O. Chiellin (Eds.), Technomic Publishing Co., Lancaster, PA, 1992, p. 23.]... 

Johnson et al. (15) reported the first attempt to synthesize PEEK by polycondensation of bisphenolate with activated dihalides using DMSO as a solvent and NaOH as a base. High molecular weight polymers were difficult to obtain due to the crystallinity and the resulting insolubility of polymers in DMSO. To circumvent the solubility problem, Attwood and Rose (16) used diphenyl sulfone as a solvent, and the polymerization was carried out close to the melting point. Victrex PEEK was commercialized by the British company ICI in 1982 using this method. Since its commercialization, this thermoplastic polymer has been used in a wide range of applications, from medicine to the electronic, telecommunications and transport industries (automobile, aeronautic and aerospace) (17,18). 

The interest in polyelectrolyte investigations has increased in the last few years as evidenced by the first two International Symposiums on Polyelectrolytes, held in 1995 and 1998. The number of papers dealing with polyelectrolytes has also increased substantially. This is not surprising considering the wide application of natural and synthetic polymers in medicine,... 

Duncan, R., Kopecek, J. and Lloyd, J.B. (1983) Development of N-(2-hydroxypropyl)-methaciylamide copolymers as carriers of therapeutic agents. In Chiellini, E. and Guisti, P. (eds). Polymers in Medicine Biomedical and Pharmacological Applications, pp. 97-114. Plenum Press, New York. 

A review is presented of the applications of synthetic polymers in medicine. The major uses of these biomaterials are in devices and implants for diagnosis or therapy. The composition and properties, characterization, and biologic interactions of a wide variety of synthetic polymers are reviewed. Biologic testing and clearance of biomaterials for clinical use are also covered. 

The word latex has become a generic term that applies to all kinds of polymer colloidal dispersions, including those found in nature and those obtained by emulsion polymerization. Latex obtained from the sap of certain trees was used around 1600 BC by the Mayas in the ancient Mesoamerica for medicines, paints, manufacturing of rubber balls, waterproof cloths, and other mbber artifacts [1]. At present, there are a vast number of applications of polymer latexes, some of which are mentioned below. The growing variety of applications and environmental concerns has constituted the driving force for the development of this fleld. 

The review by Barrows is brief with an emphasis on their applications with an extensive Hsts of patents. The book and chapter by Chu et al. focuses on the most successful use of biodegradable polymers in medicine, namely wound closure biomaterials like sutures. It is so far the most comprehensive review of aU aspects of biodegradable wound closure biomaterials with very detailed chemical, physical, mechanical, biodegradable, and biological information. The chapter by Kimura is an overview of the subject with... 

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