Reconstituted collagen

Kqrwords Extracellular matrix Fibronectin Collagen Reconstitution... 

Rodiere, E., Bocherens, H. Angilbault, J-M. and Mariotti, A. 1996 Particularites isotopiques de I azote chez le chevreuil (Capreolus capreolus L) Implications pour les reconstitutions paleoenvironnementales. Comptes Rendu de I Academie des Sciences de Paris 323 179-185. Schoeninger, M.J. 1985 Trophic level effects on N/ N and ratios in bone collagen and... 

The effect of various chemical modifications on the mechanical properties of reconstituted collagen and the diffusion rates of the steroid medroxyprogesterone was investigated (38). Formaldehyde-treated films, which are heavily crosslinked, have high moduli and low rates of drug release. Films treated with chrome quickly become hydrated in solution and have low moduli and very rapid drug release characteristics. 

M El-Samaligy, P Rohdewald. Reconstituted collagen nanoparticles, a novel drug carrier delivery system. J Pharm Pharmacol 35 537-539, 1983. 

Collagen sponges with microporous structures from tilapia were fabricated reconstituted collagen fibrils using freeze-drying and cross-linked by DHT treatment or additional treatment with WSC treatment. The pellet implantation tests into the paravertebral muscle of rabbits demonstrated that tilapia collagen caused rare inflammatory responses at 1- and... 

Reconstituted acid-soluble collagen from various mineralized and unmineralized tissues have been examined for their potential to pick up calcium and phosphate from buffered solutions, and for their capacity to induce nucleation of a mineral phase426-434. Some collagens were good, others poor catalysts428,429 and apatite deposition proceeded in the presence of soft as well as of hard tissue collagens. The uptake of calcium ions requires the presence of phosphate ions and vice versa the Ca/P ratio is close to that of apatite (1.5—1.8)431. Study of exchange reactions by isotope tracers between solvent und substrate revealed that in absence of either... 

Ortolani, F., Giordano, M., and Marchini, M. (2000). A model for type II collagen fibrils Distinctive D-band patterns in native and reconstituted fibrils compared with sequence data for helix and telopeptide domains. Biopolymers 54, 448-463. 

Ronziere, M-C., Berthet-Colominas, C., and Herbage, D. (1987). Comparative structural studies of reconstituted and native type I and type II collagen fibrils by low angle X-ray diffraction. Biochim. Biophys. Acta 916, 381-387. 

Bornstein MB (1958) Reconstituted rattail collagen used as substrate for tissue cultures on coverslips in Maximow slides and roller tubes. Lab Invest 7 134-137 Bowman PD, Ennis SR, Rarey KE et al. (1983) Brain microvessel endothelial cells in tissue culture a model for study of blood-brain barrier permeability. Ann Neurol 14 396-402 Eisenblatter T, Galla HJ (2002) A new multidrug resistance protein at the blood-brain barrier. Biochem Biophys Res Com-mun 293 1273-1278... 

Fig. 13. Schematic view of the periodic fine structure (phosphotungstic acid-stained) of the repeating elements of various reconstituted collagens native pattern, fibrous long spacing (FLS) collagen and segment long spacing (SLS) collagen. (From Schmitt et al., 1955.)...

Schmitt and his collaborators found that by judicious manipulation of the solvent environment they could roprecipitate soluble collagen in at least five different fibrous modifications. Briefly, they found that by adding increasing quantities of salt to a dilute acetic acid solution of soluble collagen, they could produce reconstituted collagens which showed (1) the normal 640 A polarized banding at 1 % NaCl, (2) an abnonnal, 210 A periodicity at 2% NaCl, and (3) no periodicity at 5% NaCl (see Fig. 15). 

A proportion of the denatured material has been shown to have undergone true reconstitution by the fact that its denaturation temperature (Flory and Garrett, 1958), electron microscope forms (Rice, 1960 Veis and Cohen, 1960), and resistance to enzymes (Kiihn, 1963) are the same as those of the original collagen. The steps involved in the reversion process have been discussed by von Hippel and Harrington (1959) and Flory and Weaver (1960). 

Veis and Cohen (1960) found that reconstitution to collagen, as shown by electron micrographs, only occurred for multichain gelatins. They suggested that the chains must be held in the collagen form for a small region near the cross-links. These regions form the nuclei for subsequent reversion. 

The structure and physical properties of collagen are well known. Several recent reviews are available to interested readers (3, 4, 5, 6, 7,8). Some of the work pertinent to the problems of using collagen as a biomaterial along with some of our recent work on reconstituting collagen surfaces are reviewed here. 

Figure 23 Mammalian bone at different levels of resolution (a) Collagen fibril with associated mineral, (b) Woven bone (random collagen distribution), (c) Lamellar bone showing separate lamellae with collagen organized in domains with preferred orientation alternating in adjacent lamellae, (d) Woven bone with blood channels shown as dark spots, woven bone stippled, (e) Primary lamellar bone orientation indicated by dashes, (f) Haversian bone, a collection of haversian systems are shown as a longitudinal structure. Each system has concentric lamellae around a central blood channel. Darkened area represents an empty (eroded) portion of the section which will be reconstituted with new bone, (g) Alternation of woven and lamellar bone, (h) Various orientations of heavily mineralized (cortical, or compact) bone, (i) Trabecular, or cancellous, bone (Wainwright et aL, 1976) (reproduced by permission of Hodder Arnold from Mechanical Design in Organisms, 1976).

Bornstein MB (1958) Reconstituted rat tail collagen used as substrate for time tissue cultures on coverslips in Maximow slides and roller tubes. Lab Invest 7 134-139... 

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