| Abstract
| - Double-stranded (ds) DNA from salmon testes has been incorporated into PVA hydrogels obtained by a techniqueof repeated freezing and thawing. The cryogels obtained are free of potential toxic species like chemical cross-linkers,and consequently, they can be used in pharmaceutical or medical applications. These cryogels show a good mechanicalresistance and a white and opaque appearance caused by a heterogeneous porous structure. Encapsulated DNA moleculescan be in a compacted or an extended conformation in the PVA matrix and can be controlled by tailoring the degreeof crystallinity of the PVA network; this is supported by fluorescence microscopy and UV and FTIR spectroscopicstudies. The two forms of encapsulated DNA were observed for different types of matrixes: an extended one in amore crystalline network and a globular one in a more amorphous one. Different associations of base pairs have alsobeen observed. PVA cryogel crystallinity could be tailored by the cryogel contact with different salt solutions. Cryogelsurface (scanning electron microscopy) and bulk morphology (porosimetry), swelling, DNA retention, and deliverykinetics have also been studied. All these investigations clearly show strong interactions between PVA and DNA.
|
