Periodate-induced viscosity decreases in aqueous solutions of acetal- and ether-linked polymers

Scott, J. E.; Tigwell, M J

doi:10.1016/s0008-6215(00)82856-6

Cited by 28 publications

(10 citation statements)

References 10 publications

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“…Thus some caution should be exercised in assuming that the results faithfully reflect the exact properties of intact RSM. It has been shown by Scott et al (1972) and Scott & Tigwell (1973) that certain proteoglycans and glycosaminoglycuronans lose viscosity after treatment with 0.1 M-periodate, an effect that has been attributed to the rupture of glycosidic links by the generation of free hydroxy radicals from periodate. In principle, any polysaccharide polymers might be susceptible to the same glycosidic bond breakage although no study of mucin oligosaccharide chains has been performed to confirm it.…”

Section: Discussionmentioning

confidence: 99%

Purification and immunofluorescent localization of rat submandibular mucin

Fleming

Brent

Arellano

et al. 1982

Biochemical Journal

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Rat submandibular mucin (RSM) was purified by acid precipitation, then alcohol precipitation of the 30000g supernatant of gland homogenate, followed by column chromatography on Sephadex G-200. The mucin, which was eluted in the void volume, had an amino acid profile typical of a salivary mucus glycoprotein with high proportions of threonine, serine and proline (48.8% of total amino acids), and low proportions of aromatic and basic amino acids. It consisted of 63% (w/w) carbohydrate, which was shown by g.l.c. analysis to contain N-acetylglucosamine, N-acetylgalactosamine, galactose, sialic acid and fucose in the proportions 1.0:3.4:2.6:3.1:1.2. After staining of the mucin with periodic acid/Schiff reagent, analytical equilibrium ultracentrifugation in a CsCl density gradient produced a symmetrical peak of buoyant density 1.449g/ml, without evidence of protein contaminants. Sedimentation velocity centrifugation revealed a major periodate/Schiff-positive component (S(0) (20,w) 5.06) with an associated shoulder of slower sedimenting material, suggesting polydispersity in the size of the mucin. Our findings suggest that the RSM purified in these studies has a molecular weight between 200000 and 1x10(6). Antibody to RSM was prepared in a rabbit and produced a single precipitin line on immunoelectro-osmophoresis with the mucin. Immunofluorescence studies showed that the antibody localized only to submandibular acinar cells and confirmed that these cells were the source of RSM. The antibody was not directed towards the blood-group-A determinant (terminal N-acetylgalactosamine) present in the mucin.

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Section: Discussionmentioning

confidence: 99%

Purification and immunofluorescent localization of rat submandibular mucin

Fleming

Brent

Arellano

et al. 1982

Biochemical Journal

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“…The higher activity of periodate may be attributed to the formation of a number of highly reactive radicals and non-radical intermediates according to the following scheme [11,14,17,24]: …”

Section: Resultsmentioning

confidence: 99%

UV-induced decolourization of acid alizarine violet N by homogeneous advanced oxidation processes

Sadik¹,

Nashed²

2008

Chemical Engineering Journal

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“…While the oxidation of alg has been studied since the 1970s [67][68][69][70][71], the real scope of this process emerged with the development of alg derivatives for tissue engineering applications, requiring finely tuned degradability. The most common reagent used for alg oxidation is sodium periodate (NaIO 4 ), under aqueous, dark conditions.…”

Section: Oxidation Without Further Modificationmentioning

confidence: 99%

Strategies to Functionalize the Anionic Biopolymer Na-Alginate without Restricting Its Polyelectrolyte Properties

2020

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The natural anionic polyelectrolyte alginate and its derivatives are of particular interest for pharmaceutical and biomedical applications. Most interesting for such applications are alginate hydrogels, which can be processed into various shapes, self-standing or at surfaces. Increasing efforts are underway to functionalize the alginate macromolecules prior to hydrogel formation in order to overcome the shortcomings of purely ionically cross-linked alginate hydrogels that are hindering the progress of several sophisticated biomedical applications. Particularly promising are derivatives of alginate, which allow simultaneous ionic and covalent cross-linking to improve the physical properties and add biological activity to the hydrogel. This review will report recent progress in alginate modification and functionalization with special focus on synthesis procedures, which completely conserve the ionic functionality of the carboxyl groups along the backbone. Recent advances in analytical techniques and instrumentation supported the goal-directed modification and functionalization.Polymers 2020, 12, 919 2 of 23 Physicochemical and Polyelectrolyte Characteristics of AlginateThe composition, internal structure, and molar mass of the alg backbone govern the functional properties [9]. The solubility of alg in water depends on the pH value and the type of the counterions of the carboxyl groups. At pH < 3, both the M-and G-structures will precipitate as alginic acid. However, alternating M-and G-structures precipitate at lower pH values compared to the alg containing Polymers 2020, 12, 919 3 of 23 more homogeneous block structures. Neutralization of the alginic acid occurs at pH > 4, where it is converted into its corresponding salt [10]. Na-alg is an example of a water-soluble alg.Na-alg behaves in aqueous solution as a typical linear homogeneously charged polyelectrolyte. The chain conformation and consequently the solution viscosity strongly depend on the ionic strength, i.e., on both the alg concentration and the simultaneous presence of low molar mass salt. The intramolecular electrostatic repulsion between the neighboring negatively charged carboxyl groups of each monomer unit forces alg molecules into an extended random coil conformation in aqueous solution [11]. This results in highly viscous solutions even at relatively low alg concentration. The dynamic viscosity increases exponentially with the molar mass, while the intrinsic flexibility of the alg chains in solution increases in the order GG < MM < MG [12]. On the other hand, the selectivity for cation-binding and gel-forming properties strongly depends on the composition and sequence. Divalent cations preferably bind to the G-blocks. The ability to form ionotropic gels is based on this selective binding of cations. Mixing solutions of Na-alg with solutions of cationic polyelectrolytes yields precipitates of polyelectrolyte complexes.The rheological behavior of Na-alg solutions is important for a number of technologies and depends on both the concentration and th...

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Periodate-induced viscosity decreases in aqueous solutions of acetal- and ether-linked polymers

Cited by 28 publications

References 10 publications

Purification and immunofluorescent localization of rat submandibular mucin

Purification and immunofluorescent localization of rat submandibular mucin

UV-induced decolourization of acid alizarine violet N by homogeneous advanced oxidation processes

Strategies to Functionalize the Anionic Biopolymer Na-Alginate without Restricting Its Polyelectrolyte Properties

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