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| Author(s): |
Marcio de Paula
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC/BT) |
| Defense date: | 2003-09-19 |
| Examining board members: |
Gilberto Goissis;
Eliana Aparecida de Rezende Duek;
Sonia Maria Malmonge;
Ana Maria de Guzzi Plepis;
Cecília Amélia de Carvalho Zavaglia
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| Advisor: | Gilberto Goissis |
| Abstract | |
This work describes the preparation, characterization and mechanisms of interaction anionic collagen:rhamsam composites, with the purpose of developing injectable gels for plastic corrections with similar concentrations to the commercially founded without the use of glutaraldehyde. The materials were characterized by electrophoresis, infrared spectroscopy, thermal stability, rheological properties and fluidity tests. The materials obtained independently from processing are formed by no desnaturated collagen with the preservation of secondary structure protein. The rheological studies showed a viscoelastic behavior for all the preparations independently of pH, and with storage modulus always greater than the loss modulus (G>G and d<45o), as well a higher resistence to the deformation of anionic collagen:rahamsan gels equilibrated at pH 7.4 in relation to the gels equilibrated at pH 3.5. Measure of viscosity showed that besides a non Newtonian behavior of the polysaccharide addition even at low concentrations causes significant effects on the viscosity of the gels, indicating that collagen:rhamsan interaction probably occurs due to the water disposition around the complex already formed and it does not damage the secondary structure of the collagen. On the other hand, dynamic viscosity found for different preparations indicate that the composites obtained are potential candidates to be utilized in laringology. Flow experiments indicated that the force needed for the extrusion for anionic collagen:rhamsan composites, in comparison to anionic collagen, was significantly smaller and associated with a smooth flow, suggesting that the collagen anionic:rhamsan association can substitute glutaraldehyde with advantage in the stabilization for the gels commercial preparations. (AU) | |