Other Biomedical Devices

Many complex systems have been spread on liquid interfaces for a variety of reasons. We begin this chapter with a discussion of the behavior of synthetic polymers at the liquid-air interface. Most of these systems are linear macromolecules however, rigid-rod polymers and more complex structures are of interest for potential optoelectronic applications. Biological macromolecules are spread at the liquid-vapor interface to fabricate sensors and other biomedical devices. In addition, the study of proteins at the air-water interface yields important information on enzymatic recognition, and membrane protein behavior. We touch on other biological systems, namely, phospholipids and cholesterol monolayers. These systems are so widely and routinely studied these days that they were also mentioned in some detail in Chapter IV. The closely related matter of bilayers and vesicles is also briefly addressed. 

Incorporation of antimicrobials into polymers has been commercially applied in drug and pesticide delivery, surgical implants and other biomedical devices. Few food-related applications have been commercialised, but the number of articles and patents indicate that research on this subject has more than doubled in the last five years. 

Hydroxyethyl methyl Methacrylate n A monomer that polymerizes to a hydrophilic polymer that is rigid when dry but when saturated with water becomes a soft, clear material (Hydron ). Applications include masonry coatings, soft contact lens, and other biomedical devices. 

The realization of sensitive bioanalytical methods for measuring dmg and metaboUte concentrations in plasma and other biological fluids (see Automatic INSTRUMENTATION BlosENSORs) and the development of biocompatible polymers that can be tailor made with a wide range of predictable physical properties (see Prosthetic and biomedical devices) have revolutionized the development of pharmaceuticals (qv). Such bioanalytical techniques permit the characterization of pharmacokinetics, ie, the fate of a dmg in the plasma and body as a function of time. The pharmacokinetics of a dmg encompass absorption from the physiological site, distribution to the various compartments of the body, metaboHsm (if any), and excretion from the body (ADME). Clearance is the rate of removal of a dmg from the body and is the sum of all rates of clearance including metaboHsm, elimination, and excretion. 

A great number of researches have so far been carried on the incorporation of poly(IPAAm) and its copolymers in various biomedical devices, utilizing soluble/insoluble or swelling/deswelling processes in the temperature range of LCST. As overviewed by Okano et al. [44] these include drug delivery system (DDS) solute separation concentration of dilute solutions immobilization of enzymes detachment of cultured cells coupling to biomolecules, and other aspects. 

This book is intended to provide a background and training suitable for application of impedance spectroscopy to a broad range of applications, such as corrosion, biomedical devices, semiconductors and solid-state devices, sensors, batteries, fuel cells, electrochemical capacitors, dielectric measurements, coatings, elec-trochromic materials, analytical chemistry, and imaging. The emphasis is on generally applicable fundamentals rather than on detailed treatment of applications. The reader is referred to other sources for discussion of specific applications of impedance. ... 

Due to high biocompability and large surface are of cobalt oxide nanoparticles it can be used for immobilization of other biomolecules. Flavin adenine FAD is a flavoprotein coenzyme that plays an important biological role in many oxidoreductase processes and biochemical reactions. The immobilized FAD onto different electrode surfaces provides a basis for fabrication of sensors, biosensors, enzymatic reactors and biomedical devices. The electrocatalytic oxidation of NADH on the surface of graphite electrode modified with immobilization of FAD was investigated [276], Recently we used cyclic voltammetry as simple technique for cobalt-oxide nanoparticles formation and immobilization flavin adenine dinucleotide (FAD) [277], Repeated cyclic voltammograms of GC/ CoOx nanoparticles modified electrode in buffer solution containing FAD is shown in Fig.37A. 

The realistic applications of the nanotechnology itself are not very clear at present however, many research projects were related to the miniaturization for the electronics, sensors, immunodiagnos-tics, and other biomedical applications. Another approach of nanotechnology is development of metal nanostructure which can be useful as catalysts for various industrial processes, energy conversion devices, or environmental applications. 

One major problem with inserting any type of biomedical device into the body that comes into contact with blood or other body fluids is that of biofouling. Both proteins and cells can adhere strongly to many foreign surfaces. In the case of devices such as contact lenses, for example, lipids and tear proteins can adsorb onto the surface of the lens. This can cause clouding of the lens, rendering it unsuitable for use, or lead to irritation. The irreversible adsorption of proteins and cells... 

Inovio Biomedical Corporation (San Diego, CA) have developed a prototype electroporation transdermal device, which has been tested with various compounds with a view to achieving gene delivery, improving drug delivery and aiding the application of cosmetics. Other transdermal devices based on electroporation have been proposed by various groups [38 1] however, more clinical information on the safety and efficacy of the technique is required to assess the future commercial prospects. 

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