Biopolymers collagen

Optical measurements often have a greater sensitivity compared with mechanical measurements. Semidilute polymers, for example, may not be sufficiently viscous to permit reliable transient stress measurements or steady state normal stress measurements. Chow and coworkers [113] used two-color flow birefringence to study semidilute solutions of the semirigid biopolymer, collagen, and used the results to test the Doi and Edwards model discussed in section 7.1.6.4. That work concluded that the model could successfully account for the observed birefringence and orientation angles if modifications to the model proposed by Marrucci and Grizzuti [114] that account for polydispersity, were used. 

Chitosan has been associated with other biopolymers and with synthetic polymer dispersions to produce wound dressings. Biosynthetic wound dressings composed of a spongy sheet of chitosan and collagen, laminated with a gentamicyn sulphate-impregnated polyurethane membrane, have been produced and clinically tested with good results. 

Polymers are substances whose molecules are very large, formed by the combination of many small and simpler molecules usually referred to as monomers. The chemical reaction by which single and relatively small monomers react with each other to form polymers is known as polymerization (Young and Lovell 1991). Polymers may be of natural origin or, since the twentieth century, synthesized by humans. Natural polymers, usually referred to as biopolymers, are made by living organisms. Common examples of biopolymers are cellulose, a carbohydrate made only by plants (see Textbox 53) collagen, a protein made solely by animals (see Textbox 61), and the nucleic acid DNA, which is made by both plants and animals (see Textbox 64). 

Proteins, the main constituents of the animals body, are polypeptides, biopolymers consisting of many amino acid molecules (the monomers) combined together (see Chapter 11) collagen, for example, the main component of animal skin, is a complex protein consisting of many molecules of amino acids combined together into polypeptide chains (see Fig. 71). Polysaccharides, the essential constituents of plants, also consist of many monosaccharide molecules combined together. Cellulose, the most abundant biological material on earth, which makes up most of the structural... 

Abstract Synthetic polymers and biopolymers are extensively used within the field of tissue engineering. Some common examples of these materials include polylactic acid, polyglycolic acid, collagen, elastin, and various forms of polysaccharides. In terms of application, these materials are primarily used in the construction of scaffolds that aid in the local delivery of cells and growth factors, and in many cases fulfill a mechanical role in supporting physiologic loads that would otherwise be supported by a healthy tissue. In this review we will examine the development of scaffolds derived from biopolymers and their use with various cell types in the context of tissue engineering the nucleus pulposus of the intervertebral disc. 

Ti values may occur with such native biopolymers as ribonuclease A, deoxyribonucleic acid, and collagen, whose molecular motions are restricted, but, as yet, high values have not been observed for polysaccharides in solution, or for gels, in which these motional-restriction effects may be equivalent, or less marked. However, an extensive relaxation-study by Levy and coworkers68 on poly(n-alkyl methacrylates) may serve as a model for future experiments on polysaccharides, as this type of molecule has a main chain and side chains, albeit more mobile than those in polysaccharides. 

Gelatin is a biopolymer it is denaturated collagen. Due to its natural origin, differences exist between the molecular composition... 

Berisio, R., Vitagliano, L., Mazzarella, L., and Zagari, A. (2001). Crystal structure of a collagen-like polypeptide with repeating sequence Pro-Hyp-Gly at 1.4A resolution Implications for collagen hydration. Biopolymers 56, 8-13. 

Burjanadze, T. V. (2000). New analysis of the phylogenetic change of collagen thermostability. Biopolymers 53, 523-528. 

Fields, G. B., and Prockop, D. J. (1996). Perspectives on the synthesis and application of triple-helical, collagen-model peptides. Biopolymers 40, 345-357. 

Klein, T. E., and Huang, C. C. (1999). Computational investigations of structural changes resulting from point mutations in a collagen-like peptide. Biopolymers 49, 167-183. 

Ramachandran, G. N., and Chandrasekharan, R. (1968). Interchain hydrogen bonds via bound water molecules in the collagen triple-helix. Biopolymers 6, 1649-1658. 

Chapman, J. A. (1989). The regulation of size and form in the assembly of collagen fibrils in vivo. Biopolymers 28, 1367—1382. 

Helseth, D. L., Jr., Lechner, J. H., and Veis, A. (1979). Role of the amino-terminal extrahelical region of type I collagen in directing the 4D overlap in fibrillogenesis. Biopolymers 18, 3005-3014. 

Jones, E. Y., and Miller, A. (1987). Models for the N-terminal and C-terminal telopep-tide regions of interstitial collagens. Biopolymers 26, 463-480. 

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