Characterisation of the nanoporous structure of collagen-glycosaminoglycan hydrogels by freezing-out of bulk and bound water

Mikhalovska, Lyuba; Гунько, В.М.; Туров, В. В.; Zarko, Vlad I.; James, Stuart L.; Vadgama, Pankaj; Tomlins, P E; Mikhalovsky, Sergey V.

doi:10.1016/j.biomaterials.2006.02.010

Cited by 11 publications

(24 citation statements)

References 40 publications

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“…First, there is unbound water, UBW, or strongly associated water, SAW, located in broad micropores and macropores; it does not interact with the pore walls and behaves as pure bulk water (Table 1) SBW remains unfrozen at T < 15 o C [50][51][52][53][54][55]. In contrast to the unbound water which is comprised of only SAW, water in other two energetic states, WBW and SBW (Table 1), can include both SAW (large clusters, nanodomains [1]) and weakly associated water (WAW) with small 1D or 2D or strongly branched 3D clusters located at mosaic polar/nonpolar surfaces [50,51].…”

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confidence: 99%

“…Contributions of different forms of water depend on the porous structure and surface chemistry of the pore walls, as well as on the composition of the solution. Detailed analysis of bound water, especially with application of low-temperature 1 H NMR, cryoporometry (NMR), relaxometry (NMR, TSDC, DRS) and thermoporometry (DSC, TG) methods [1,5,[50][51][52][53][54], can…”

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confidence: 99%

“…Therefore, determination of the amounts of different types of water in cryogels [50,51,54] is of importance to understand the nature of adsorption/desorption and diffusion processes within the pore network in cryogels, as well as to estimate the biocompatibility and structural organisation of whole cryogels [2][3][4][10][11][12][13][14][15][16][17][18][19][20][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49]54]. A variety of experimental methods sensitive to the water state can be used for these purposes [50][51][52][53][54][55][56]. Low-temperature 1 H NMR spectroscopy with layer-by-layer freezing-out of bulk and bound waters gives information on the temperature dependence of the amounts of all the above mentioned ...…”

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confidence: 99%

“…The NMR cryoporometry technique was used to analyse nanopores (d < 100 nm) in collagen hydrogels, but without detailed analysis of micro/macropores [52]. More detailed structural characterisation of glycosaminoglycan-cross-linked collagen hydrogel INTEGRA TM was carried out using a combined CLSM-NMR-cryoporometry approach [106].…”

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confidence: 99%

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Cryogels: Morphological, structural and adsorption characterisation

Gun'ko

Savina

Mikhalovsky

2013

Advances in Colloid and Interface Science

286

205

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*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.

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Cryogels: Morphological, structural and adsorption characterisation

Gun'ko

Savina

Mikhalovsky

2013

Advances in Colloid and Interface Science

286

205

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“…Relative mean errors for measured TSD current were ±5%, ±2 K for temperature, and ±5% for the temperature change rate. The TSDC method has been described in detail elsewhere [18][19][20][21][22][23][24]. The distribution function of the activation energy of depolarisation f (E) linked to dipole re-orientations, which cause the TSD current (experimentally measured), was calculated using equation (1) [24]:…”

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Interaction of unmodified and partially silylated nanosilica with red blood cells

et al. 2007

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Abstract:Interaction of red blood cells (RBCs) with unmodified and partially (50%) silylated fumed silica A-300 (nanosilica) was studied by microscopic, XRD and thermally stimulated depolarisation current (TSDC) methods. Nanosilica at a low concentration C A−300 < 0.01 wt.% in buffered aqueous suspension is characterised by a weak haemolytic effect on RBCs. However, at C A−300 = 1 wt% all RBCs transform into shadow corpuscles because of 100% haemolysis. Partial (one-half) hydrophobization of nanosilica leads to reduction of the haemolytic effect in comparison with unmodified silica at the same concentrations. A certain portion of the TSDC spectra of the buffered suspensions with RBC/A-300 is independent of the amounts of silica. However, significant portions of the low-and high-temperature TSDC bands have a lower intensity at C A−300 = 1 wt% than that for RBCs alone or RBC/A-300 at C A−300 = 0.01 wt.% because of structural changes in RBCs. Results of microscopic and XRD investigations and calculations using the TSDC-and NMR-cryoporometry suggest that the intracellular structures in RBCs (both organic and aqueous components) depend on nanosilica concentration in the suspension.

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Identification of Muir–Torre syndrome among patients with sebaceous tumors and keratoacanthomas

Ponti

Losi

Gregorio³

et al. 2005

Cancer

135

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The three‐dimensional architecture of the right ventricular myocardium is a major determinant of function, but as yet no investigator‐independent methods have been used to characterize either the normal or hypertrophied state. We aimed to assess and compare, using diffusion tensor magnetic resonance imaging, the normal architecture with the arrangement induced by chronic hypertrophy. We randomized 20 female 5 kg piglets into pulmonary trunk banding (N = 16) and sham operation (N = 4). Right ventricular hypertrophy was assessed after 8 weeks. The excised and fixed hearts were subject to diffusion tensor imaging to determine myocyte helical angles, and the presence of any reproducible tracks formed by the aggregated myocytes. All banding animals developed significant right ventricular hypertrophy, albeit that no difference was observed in terms of helical angles or myocardial pathways between the banded animals and sham group animals. Helical angles varied from ∼70 degrees endocardially to −50 degrees epicardially. Very few tracks were circular, with helical angles approximating zero. Reproducible patterns of chains of aggregated myocytes were observed in all hearts, regardless of group. The architecture of the myocytes aggregated in the walls of the right ventricle is comparable to that found in the left ventricle in terms of endocardial and epicardial helical angles, however the right ventricle both in the normal and the hypertrophied state lacks the extensive zone of circular myocytes seen in the mid‐portion of the left ventricular walls. Without such beneficial architectural remodelling, the porcine right ventricle seems unsuited structurally to sustain a permanent increase in afterload. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.

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Characterisation of the nanoporous structure of collagen-glycosaminoglycan hydrogels by freezing-out of bulk and bound water

Cited by 11 publications

References 40 publications

Cryogels: Morphological, structural and adsorption characterisation

Cryogels: Morphological, structural and adsorption characterisation

Interaction of unmodified and partially silylated nanosilica with red blood cells

Identification of Muir–Torre syndrome among patients with sebaceous tumors and keratoacanthomas

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