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medium). The relatively narrow range of variation complexes decay can occur.
On the one hand, this negative phenomenon in the need to use an interpolymer
complex as a hydrogel. On the other hand, these hydrogels can be used as
polymeric carriers objective compounds - drugs. Adjustable hydrogel
destruction allows release the drug substance in a desired area of the living body.
If necessary, hardening interpolymer complexation hydrogels complement
the processes leading to the emergence of covalent bonds between the
macromolecules. There are several variants of such processes. The simplest - the
processing of the polymer system of high-energy radiation. Thus, the hydrogel
comprising PEO and PVA were irradiated by fast electrons, resulting in the
formation of the composition used in conjunction with a dressing material for
accelerating wound healing [18]. After healing, a hydrogel film is easily peeled
from the regenerated tissue wherein the dressing remains in the hydrogel.
Another example relates to the preparation of the PEO hydrogel and K -
Carrageenan - polysaccharide containing sulphate groups, which were exposed
to y-radiation [19]. The result is a composite hydrogel without disintegrating and
retaining good mechanical properties even after sterilization in an autoclave.
The lack of such technology - the complexity of choosing the optimal
radiation dose, obespechivayushey crosslinking polymer composition with
minimal degradation of the polymer. Better handling processes, in which the
chemical reaction between the functional groups of the polymers. Generally, the
polymers used for the structuring of a low molecular weight crosslinker, the
nature of which is determined by the type of cross-linkable groups. Examples of
a few songs, including a cross-linking agent: PVA-chitosan-glutaraldehyde [20],
the PIP-carboxymethyl-carbodiimide [21], PVA-xanthan-epichlorohydrin [22].
Hardening interpolymer hydrogels by covalent bonds gives a considerable
gain in the material properties. It is indicative of the results given in [23], where
the composite hydrogels of gelatin and a so-called bacterial cellulose reinforced
carbodiimide crosslinking. Bacterial cellulose is a product obtained by culturing
in
Acetobacter Xylinum Hestrin
environment - Schramm. The composite
hydrogel gelatin-Bacterial cellulose (50:50) at a degree of swelling in water 3.10
had an elastic modulus in compression 3.9 MPa and 21 MPa, elongation, instead
of 1.2 and 1.8 MPa, respectively for gelatin with a degree of swelling of 3.80.
Similar results were obtained for hydrogels where gelatin is used instead of the
polysaccharide. For a combination of bacterial cellulose-sodium alginate set
parameters: the degree of swelling in water 20.0 compressive modulus of 0.61
MPa and a tensile 6.7 MPa. The corresponding figures for the hydrogel based on
sodium alginate with a close value of the degree of swelling (22.0) 0.14 and 0.
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