Cryotropic structuring of aqueous dispersions of fibrous collagen: influence of the initial pH values

Podorozhko, E. A.; Kurskaya, E. A.; Kulakova, V. K.; Lozinsky, V. I.

doi:10.1016/s0268-005x(99)00054-5

Cited by 20 publications

(16 citation statements)

References 18 publications

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“…Over the past decades, the freeze-thawing process has been investigated extensively to treat solutions of different polymer materials, including both natural biopolymers and synthetic polymers, by freezing below 0 • C and thawing back to room temperature [7][8][9][10]. Such biomaterials generally exhibit a fibril network structure possessing good viscoelastic behavior and high mechanical strength [11,12].…”

Section: Introductionmentioning

confidence: 99%

Effect of cyclic freeze–thawing process on the structure and properties of collagen

Ding

Zhang

2015

International Journal of Biological Macromolecules

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Section: Introductionmentioning

confidence: 99%

Effect of cyclic freeze–thawing process on the structure and properties of collagen

Ding

Zhang

2015

International Journal of Biological Macromolecules

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“…The polymer gel phase is formed during one of the stages of the cryogenic treatment: during freezing of the initial system, during storage of the samples in the frozen state or during thawing of the frozen specimens. (1, [3][4][5][6] Recently, the structuring of different polymers by applying a cryogenic treatment has attracted a lot of attention, as indicated by the following examples. For a thiol-containing poly(acryl amide) derivative, the conditions were optimized in order to obtain an insoluble gel after freezing-thawing.…”

Section: Introductionmentioning

confidence: 99%

Effect of Cryogenic Treatment on the Rheological Properties of Gelatin Hydrogels

Vlierberghe

Dubruel

Schacht

2010

Journal of Bioactive and Compatible Polymers

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Above the critical gelation concentration, gelatin has the ability to form a gel when cooled below the sol-gel temperature. In the present work, freeze-thaw cycles were implemented on gelatin solutions possessing varying concentrations. The rheological properties of the cryogels developed were compared with hydrogels formed at room temperature. The results indicated that the rheological properties of cryogels were superior to those of the corresponding hydrogels formed at room temperature. In addition, the critical gelation concentration decreased after (repeated) cryo-treatment(s). The effect of applying various (cryo)parameters, including the number of freeze-thaw cycles, the cooling rate, the thawing rate and the gelatin concentration, on the final material properties was examined. The rheological properties of the cryogels improved with an increasing number of cryo-cycles and a decreasing cooling and thawing rate. In a second part of the work, methacrylamide-modified gelatin was treated cryogenically, followed by in situ UV-irradiation to enable radical crosslinking. It was shown that the crosslinking efficiency improved upon freeze-thawing. The latter was however limited by the gelatin concentration, which affects the chain mobility required to induce phase separation. The present work demonstrates that cryogelation offers possibilities to finetune the mechanical properties of hydrogels. The observed findings are of relevance for the field of tissue engineering, since this concept was previously applied for the development of porous gelatin hydrogels as biomaterials. In addition, a cryogenic treatment can be applied to a wide range of synthetic and natural polymers.-3 -

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“…Whereas the latter type of composite PVA cryogels, e.g., those prepared from mixed solutions of PVA and oligoethyleneglycols,28, 29 was obtained and explored, the former type was not, to the best of our knowledge, so far reported in scientific literature. It is thought that similar filled PVACGs containing liquid hydrophobic discrete phase can be of both fundamental and applied interest, for instance, as potential wound healing or cosmetic dressings carrying medicinal or cosmetic oils, respectively 30. Therefore, this study was aimed at preparing PVA‐cryogel‐based composites filled with small dispersed droplets of Vaseline oil emulsion (as model liquid hydrophobic dispersed particles) and studying the influence of such filler on the properties and morphological features of the resulting Vaseline oil‐filled PVA cryogels (vof‐PVACGs).…”

Section: Introductionmentioning

confidence: 99%

Cryostructuring of polymer systems. XXX. Poly(vinyl alcohol)‐based composite cryogels filled with small disperse oil droplets: A gel system capable of mechanically induced releasing of the lipophilic constituents

Podorozhko

Korlyukov

Lozinsky

2010

J of Applied Polymer Sci

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Composite heterophase poly(vinyl alcohol) (PVA) cryogels containing entrapped small droplets of Vaseline oil have been prepared and studied. Such oilfilled cryogels were formed via freeze-thaw treatment of freshly prepared oil-in-water emulsions containing varied volume fraction of lipophilic phase, and the influence of the amount of this phase, as well as the effects of freezing conditions on the physicomechanical (shear moduli) and thermal (gel fusion temperature and fusion enthalpy) characteristics of resulting composites have been explored. It was shown that over certain range of PVA concentrations in aqueous phase and a range of volume fraction of the hydrophobic phase its microdroplets performed as ''active'' fillers causing an increase in both the gel strength and the heat endurance of composites. The light microscopy data on the morphological features of such filled PVA cryogels revealed the effect of diminution in size of oil droplets entrapped in the gel matrix as compared with the initial emulsions. This effect can be explained by the disintegrating action of crushing and shear stresses arising upon the system freezing and growth of ice crystals. The oil-filled PVA cryogels were found to be capable of gradually releasing the lipophilic constituents (the Rose hips oil, in this case) in response to the cyclic mechanical compression.

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Cryotropic structuring of aqueous dispersions of fibrous collagen: influence of the initial pH values

Cited by 20 publications

References 18 publications

Effect of cyclic freeze–thawing process on the structure and properties of collagen

Effect of cyclic freeze–thawing process on the structure and properties of collagen

Effect of Cryogenic Treatment on the Rheological Properties of Gelatin Hydrogels

Cryostructuring of polymer systems. XXX. Poly(vinyl alcohol)‐based composite cryogels filled with small disperse oil droplets: A gel system capable of mechanically induced releasing of the lipophilic constituents

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