Synthesis and characterization of polyvinyl alcohol/cellulose cryogels and their testing as carriers for a bioactive component

Paduraru, Oana Maria; Ciolacu, Diana; Darie, Raluca Nicoleta; Vasile, Cornelia

doi:10.1016/j.msec.2012.07.033

Cited by 71 publications

(29 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, in this paper only qualitative structural characterisation of the materials was made. Physically cross-linked cryogels containing PVA and various amounts of microcrystalline cellulose prepared by freezing/thawing technique were characterised using SEM, FTIR, XRD, rheology, TG, and swelling methods [86]. However, the textural characteristics of the cryogels were not analysed in detail.…”

Section: Types Of Cryogel Based Composite and Hybrid Materialsmentioning

confidence: 99%

Cryogels: Morphological, structural and adsorption characterisation

Gun'ko

Savina

Mikhalovsky

2013

Advances in Colloid and Interface Science

288

205

View full text Add to dashboard Cite

*Graphical Abstract (for review)Cryotripic gelation technique allows the synthesis of solid and soft macroporous gels Textural characterisation of cryogel in native superhydrated state with noninvasive methods Adsorption and diffusion characteristics of macroporous cryogels with respect to macromolecules and cells Theoretical modelling of adsorption from aqueous media *Highlights (for review) Please find the revised manuscript entitled "Cryogels: morphological, structural and adsorption characterisation" by Vladimir M. Gun'ko, Irina N. Savina, Sergey V. Mikhalovsky to re-consider for publication in the "Advances in Colloid and Interface Science"The paper was completely edited and changed according to reviewers comments.Sincerely yours, Prof. V. M. Gun'koCover Letter ABSTRACTExperimental results on polymer, protein, and composite cryogels and data treatment methods used for morphological, textural, structural, adsorption and diffusion characterisation of the materials are analysed and compared. Treatment of microscopic images with specific software gives quantitative structural information on both native cryogels and freeze-dried materials that is useful to analyse the drying effects on their structure. A combination of cryoporometry, relaxometry, thermoporometry, small angle X-ray scattering (SAXS), equilibrium and kinetic adsorption of low and high-molecular weight compounds, diffusion breakthrough of macromolecules within macroporous cryogel membranes, studying interactions of cells with cryogels provides a consistent and comprehensive picture of textural, structural and adsorption properties of a variety of cryogels. This analysis allows us to establish certain regularities in the cryogel properties related to narrow (diameter 0.4 < d < 2 nm), middle (2 < d < 50 nm) and broad (50 < d < 100 nm) nanopores, micropores (100 nm < d < 100 m) and macropores (d > 100 m) with boundary sizes within modified life science pore classification. Particular attention is paid to water bound in cryogels in native superhydrated or freeze-dried states. At least, five states of water -free unbound, weakly bound (changes in the Gibbs free energy G < 0.5-0.8 kJ/mol) and strongly bound (G > 0.8 kJ/mol), and weakly associated (chemical shift of the proton resonance  H = 1-2 ppm) and strongly associated ( H = 3-6 ppm) waters can be distinguished in hydrated cryogels using 1 H NMR, DSC, TSDC, TG and other methods. Different software for image treatment or developed to analyse the data obtained with the adsorption, diffusion, SAXS, cryoporometry and thermoporometry methods and based on regularisation algorithms is analysed and used for the quantitative morphological, structural and adsorption characterisation of individual and composite cryogels, including polymers filled with solid nano-or microparticles.

show abstract

Section: Types Of Cryogel Based Composite and Hybrid Materialsmentioning

confidence: 99%

Cryogels: Morphological, structural and adsorption characterisation

Gun'ko

Savina

Mikhalovsky

2013

Advances in Colloid and Interface Science

288

205

View full text Add to dashboard Cite

show abstract

“…The hydrogels can be obtained using different chemical or physical methods [1][2][3][4][5][6][7][8][9][10][14][15][16][17][18][19][20][21][22][23][24][25]. Chemical crosslinking provides a more controllable network structure with uniform pore sizes but requires a careful purification step to remove the free unreacted crosslinker, initiator or monomers with potential toxicity.…”

Section: Introductionmentioning

confidence: 99%

“…Physical methods allow the hydrogel formation by physical interactions between macromolecules occuring in well established conditions and, in some cases, their properties and performances are comparable or even superior to those of the chemical hydrogels, as for example reversible sol-gel transition to external stimuli, such as temperature [6] or pH [4,20]. Cryogelation method was applied to PVA containing systems in order to obtain physical hydrogels with high elasticity [1-3, 5, 18, 22-24, 26], excellent swelling and long term stability [26] and very good weight-bearing properties [23], characteristics highly explored in pharmaceutical [1], biomedical and bioengineering applications [1-3, 5, 18, 22, 23, 26]. Generally, a cryogelation cycle consists in freezing the polymer solution for a given time followed by a thawing step.…”

Section: Introductionmentioning

confidence: 99%

Rheological investigation of poly(vinyl alcohol)/poly(N-vinyl pyrrolidone) mixtures in aqueous solution and hydrogel state

2016

View full text Add to dashboard Cite

Rheological behavior of poly(vinyl alcohol) (PVA) and poly(N-vinyl pyrrolidone) (PVP) mixtures in aqueous solutions and hydrogel state was investigated. The complex dependence of the viscosity on PVA/PVP mixture composition could be attributed to cumulative effects of electrostatic interactions, hydrogen bonding or association phenomena. Physical hydrogels were prepared by freezing/thawing method and their viscoelastic properties were followed as a function of number of cryogenic cycles and aging time at 37°C. From swelling experiments, it was observed that the diffusion of water molecules into the hydrogel pores is Fickian (for low number of cryogenic cycles) and it becomes pseudo-Fickian as the sample is submitted to more than 10 freezing/thawing cycles. PVA/PVP hydrogels obtained by physical interactions present a high degree of tailorability and they are suitable candidates for biomedical applications.

show abstract

“…Poly (vinyl alcohol), PVA cryogels have been studied as controlled release carriers [12]. PVA-based cryogels are often synthesized in combination with other polymers, such as chitosan, and used as a drug delivery system because this polymer is considered non-toxic and has good physical and chemical properties, film-forming ability [13], low toxicity and high biocompatibility as a biomaterial [14].…”

Section: Introductionmentioning

confidence: 99%

Poly (vinyl alcohol)/chitosan cryogels as PH responsive ciprofloxacin carriers

2016

Self Cite

View full text Add to dashboard Cite

The pH responsiveness of swelling behavior and the release of ciprofloxacin hydrochloride from poly (vinyl alcohol)/chitosan cryogels of various compositions were investigated. All cryogels swelled and reached equilibrium within 100 min, indicating that the cryogels swell relatively fast. Increasing the chitosan content in the poly (vinyl alcohol) cryogels increased the swelling capacity of the cryogels. The poly (vinyl alcohol)/chitosan cryogels exhibited a sudden change in swelling characteristics at a certain pH value of the swelling medium as critical pH of 6.37-6.68 which depends on chitosan content. Ciprofloxacin hydrochloride was loaded into poly (vinyl alcohol)/chitosan cryogels to study its in-vitro release. Drug release behavior was found to be pHdependent. The release mechanism changes with pH of the medium and mainly at critical pH. The release rate is high in acidic medium (pH 4.5 and 5.5) as compared with basic one (pH 7.4), in the last pH medium the drug being delivered in a prolonged period and with a slow release rate. The pH responsiveness indicates that these systems are interesting drug carriers for the oral formulations or as wound dressing materials.

show abstract

Synthesis and characterization of polyvinyl alcohol/cellulose cryogels and their testing as carriers for a bioactive component

Cited by 71 publications

References 55 publications

Cryogels: Morphological, structural and adsorption characterisation

Cryogels: Morphological, structural and adsorption characterisation

Rheological investigation of poly(vinyl alcohol)/poly(N-vinyl pyrrolidone) mixtures in aqueous solution and hydrogel state

Poly (vinyl alcohol)/chitosan cryogels as PH responsive ciprofloxacin carriers

Contact Info

Product

Resources

About