Poly(Vinyl Alcohol) Cryo-Hydrogel Systems for Development of Biomaterials
2013
Jolanta Staško

Defending
13.03.2013. 15:00, MLĶF, Āzenes iela 14, 272. telpa

Supervisor
Mārtiņš Kalniņš

Reviewers
Galija Šuļga, Skaidrīte Reihmane, Linda Krāģe

Cryogenic synthesis process of polyvinyl alcohol gel, as well as relationship between structure parameters and characteristics of certain individual properties of obtained gels in the region of small crosslinking density values are studied in the present work. The applied idea of the study is to create polymer material with great water sorption ability and complex of strength-deformation characteristics, which meet requarements can be used for development of effective medical dressing. Information on the use of polymers in medicine field is summarized in the review of scientific literature. Characteristic parameters of structure and properties of polymer gels and in particular polymer hydrogels are discussed. Important role of gels in the sphere of development of medical materials, particularly dressing materials, is analyzed. Poly(vinyl alcohol) (PVA) as a potential polymeric material which may be used for drug containing dressings in the form of a hydrogel is described in details. The selection of cryogenic freezing-thawing crosslinking method from other potential methods of PVA hydrogel synthesis is justified. Aim and tasks of the studies are formulated. Methodological part of the thesis contains description of the gel obtaining process and time-temperature regime characteristics of the cryogenic process. Used research methods and the determinable parameters are described: sorption and extraction methods of determination of gel content and gel sorption capacity, methods of determination of swollen gel strength-deformation parameters, DSC and TG research technique of gel structure and crosslinking process, gel morphology studies by SEM, methodology of studies of gel sorption-desorption kinetic, gel stability assessment technique, microbiological, cytotoxicity and cell proliferation assessment technique. The developed technology of cryogenic synthesis of PVA hydrogel is described in experimental part of the thesis. Temperature-time regime of cryoprocess, the range of polymer molecular mass and solution concentration, that provides formation of gel with a small degree of crosslinking, is based. Morphology of synthesized cryo-hydrogel corresponding to a composite, which consists of a water-swollen PVA gel and water inclusions (pores) with complex pore hierarchy and shape is depicted. Thermal resistance and durability of PVA cryogels in water environment as well as the stability of gels in successive sorption-desorption cycles is evaluated. It is ascertained that strength-deformation characteristics of cryogels are completely determined by crosslinking density of gels. Cytotoxicity, cell proliferation in vitro, microbial colonization level and adhesion activity of gels is illustrated. Production technology of dressing prototypes and version of technological scheme for industrial production of dressings is characterized. The 130 pages of thesis include 83 pictures and 25 tables, and a list with 100 references.


Keywords
polivinilspirts, krio-hidrogēli, pārsēji

Staško, Jolanta. Poly(Vinyl Alcohol) Cryo-Hydrogel Systems for Development of Biomaterials. PhD Thesis. Rīga: [RTU], 2013. 130 p.

Publication language
Latvian (lv)
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