Biological degradation overview

This chapter overviews the literature regarding the biodegradation processes of bioactive calcium phosphate ceramics from the viewpoint of in vitro physico-chemical dissolution processes and in vivolin vitro biological degradation processes. 

When fluorescently labeled biological specimens are viewed with a conventional wide-field microscope, a haze of out-of-focus fluorescence is usually created hy the overlapping structures within the sample. As we focus through the specimen, our hrains have a remarkable ability to discern substantial structural detail. However, the resolution of the images we record on film is degraded hy the out-of-focus fluorescence. The confocal microscope can reject out-of-focus information and enhance the contrast of an image because the illumination and the detection are confined to an identical (small) region of the specimen. An overview of the basic principles of a confocal microscope is presented in Fig. 1 and outlined helow. 

Despite their favourable properties, peptide-based drugs are under-represented in the pharmaceutical market. This discrimination is usually due to their poor bioavailability, which sometimes necessitates non-oral administration or even special medical devices such as inhalers. Another related major disadvantage of peptides is their low metabolic stability due to proteolytic degradation, hi addition, costs of goods for the drug substance are sometimes tremendous. Therefore, there is considerable interest to transform the active principle of biologically active peptides into small molecules with improved pharmacokinetic properties, hi this chapter, we present an overview of... 

Black, R.M. (2008). An overview of biological markers of exposure to chemical warfare agents. J. Anal. Toxicol. 32 2-9. Black, R.M., Muir, J. (2003). Derivatisation reactions in the chromatographic analysis of chemical warfare agents and their degradation products. J. Chromatogr. A 1000 253-81. 

Because of its unique physicochemical properties and distinctive biological qualities, this polyanionic polymer is enormously versatile. The naturally occurring material is unfortunately, too soluble and is too rapidly degradable, hence certain modifications are necessary for its practical use. There are several functional groups on HA that are exploited for chemical modifications for use in the preparation of medical materials. Such modifications are too extensive to review here, but are accessible in excellent overviews (e.g. [142]). 

Laist, D., 1987, Overview of the Biological Effects of Lost and Discarded Plastic Derbis in die Marine Environment, Marine Pollution Bulletin 18(6B) 319-326 Doi, Y., Kanesawa, Y., Tanahashi, N., Kumagai, Y., 1992, Biodegradation of microbial polyesters in the marine environment. Polymer Degradation and Stability 36 173-177... 

Abstract Site-selective peptide/protein degradation through chemical cleavage methods is an important modification of biologically relevant macromolecules which complements enzymatic hydrolysis. In this review, recent progress in chemical, site-selective peptide btuid cleavage is overviewed, with an emphasis oti postulated mechanisms and their implications on reactivity, selectivity, and substrate scope. 

Interfacial phenomena play an essential role in many biomedical applications. The reaction of the body towards implants largely depends on the surface properties of the latter. The corrosion or the degradation of materials placed in contact with biological fluids is initiated at the material-fluid interface. The successful design of biosensors or of supports for cell culture relies on the tqtpropriate modification of a material surface and on the interaction of that modified surface with macromolecules in solution or with cells. An overview of key constituents and processes that are... 

We ll begin a study of biological reactions with a general overview of metabolism and then focus specifically on amino acids, the fundamental building blocks from which the estimated 500,000 or so proteins in our bodies are made. We ll see in this chapter both how amino acids are biosynthesized for incorporation into proteins and how they are ultimately degraded when proteins are broken down. 

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