Biological hard tissues

Lipid content In biological hard tissues, lipids have been reported to be mineral nucleators [24-26]. As is the case with proteoglycans, their content is rather easily established in Raman spectra through the integrated area of the characteristic band at 1298cm [27]. 

Currey, J. D. (1996). Biocomposites micromechanics of biological hard tissues. Current Opinion in Solid State Materials Science, 1, 440-445. 

Although about 80—90 percent of the total citric acid in humans are localized in hard tissues as enamel, dentine, cementum and bones, very little is known on the biological function of citric acid in biocalcification. HA crystals are reported to be dissolved by the action of citric acid. The acid dissolves the crystals in such a way that the destruction is a preferential attack along the c-axis. It is highly probable that the HA crystallites present in mineralized tissues also do have a dislocation in the centre of the material 165). Another assumption describes that citric acid is a constituent of the aqueous phase of enamel or that citrate is bound to the surface of apatite by adsorption166). 

Lowenstam, H. A. Biogeochemistry of hard tissues, their depth and possible pressure relationships. In Barobiology and the experimental biology of the deep sea, pp. 19. Brauer,... 

Boyce, W. H. (Disc, leader) Kidney stone. In Biology of hard tissue (ed. A. M. Budy),... 

Budy, A. M. (ed.) Biology of hard tissue. New York Acad. Sci. Interdisc. Com. Progr.,... 

Richelle, L. J., and Onkelinx, C. Recent advances in the physical biology of bone and other hard tissues. In Mineral metabolism (eds. C. Comar and F. Bronner), Vol. III., pp. 123-190. New York Academic Press 1969. 

Tissues are composites of macromolecules, water, ions, and minerals, and therefore their mechanical properties fall somewhere between those of random coil polymers and those of ceramics. Table 6.1 lists the static physical properties of cells, soft and hard tissues, metals, polymers, ceramics, and composite materials. The properties listed in Table 6.1 for biological materials are wide ranging and suggest that differences in the structure of the constituent macromolecules, which are primarily proteins, found in tissues give rise to the large variations in strength (how much stress is required to break a tissue) and modulus (how much stress is required to stretch a tissue). Because most proteins are composed of random chain structures, a... 

Budy, A. M, The Biology of Hard Tissues New York Academy of Sciences New York, 1967. 

Wuthier R. E. (1984) Calcification of Vertebrate Hard Tissues. In Calcium and its Role in Biology (ed. H. Sigel). Dekker, New York, pp. 411-472. 

Human biological materials to be investigated include (a) hard calcified tissues, e.g. bone, teeth, other calcified formations (b) semi-hard tissue, e.g. hair, nails (c) soft body tissues and (d) various biological fluids and secretions in the human body. The treatment of each of these materials varies from one material to another and, as stated earlier, is often determined by the instrumental method to be employed for measuring the analytical signal, the elements to be determined and the concentration levels at which these are present. For the purposes of this discussion, it shall be generally assumed that the analytical techniques employed include atomic absorption spectrometry both with (F-AAS) as well as with a furnace (GF-AAS), neutron activation analysis (NAA), flame emission spectrometry (FES) voltammetric methods and the three inductively coupled plasma spec-trometric methods viz. ICP-atomic emission spectrometry, ICP-mass spectrometry and ICP-atomic fluorescence spectrometry. The sample preparation of biological methods for all ICP techniques is usually similar (Guo, 1989). 

Hemostats wound dressings cartilage repair soft-tissue augmentation Drug and biologically active macromolecule delivery soft- and hard-tissue augmentation... 

MTA has been found to give good biological results when used for root-end filling in vivo. It promotes only low peri-radicular inflammation [114] and frequently causes cementum to form on its surface [115], It has also been found to induce the formation of apical hard tissue [116] and, in non-infected teeth, to support almost complete regeneration of the peri-radicular periodontum [117]. Thus, MTA is not only biocompatible, it is also bioactive and generally promotes a positive response in the tissues with which it comes into contact [106,118]. 

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