&lt;i&gt;In &lt;/i&gt;&lt;i&gt;V&lt;/i&gt;&lt;i&gt;itro&lt;/i&gt;Bioactivity of Collagen/Calcium Phosphate Silicate Composites, Cross-Linked with Chondroitin Sulfate

Radev, Lachezar; Mostafa, Noha; Michailova, Irena; Salvado, Isabel M. Miranda; Fernandes, María Helena

doi:10.5923/j.ijmc.20120201.01

Cited by 12 publications

(14 citation statements)

References 39 publications

(55 reference statements)

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“…It is interesting to note that the AIM2B spectrum exhibits additional bands, sharp and of medium intensities, between 1000 and 400 cm 1 (located at 913, 538, 468 cm 1 ). To the best of our knowledge, and based on the existing bibliography, these bands suggest the presence of phosphate groups (PO4 3 ) (Radev et al, 2012). Thus, the band at 913 cm −1 can be assigned to the stretching P-O vibrations and those at 538 and 468 cm 1 can be related to the bending O-P-O vibrations of phosphate groups (Jastrzbski et al, 2011).…”

Section: Ft-ir Spectroscopymentioning

confidence: 79%

The shell matrix and microstructure of the Ram’s Horn squid: Molecular and structural characterization

Oudot

Neige

Shir

et al. 2020

Journal of Structural Biology

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Molluscs are one of the most diversified phyla among metazoans. Most of them produce an external calcified shell, resulting from the secretory activity of a specialized epithelium of the calcifying mantle. This biomineralization process is controlled by a set of extracellular macromolecules, collectively defined as the organic matrix. In spite of several studies, these components are mainly known for bivalve and gastropod classes. In the present study, we investigated the physical and biochemical properties of the internal planispiral shell of the understudied Ram's Horn squid Spirula spirula (Cephalopoda, Decabrachia, Spirulida). Scanning Electron Microscope investigations of the shell reveal a complex microstructural organization, with septa sandwiched into the shell wall, in the form of a bevel. The saccharides constitute a quantitatively important moiety of the matrix, as shown by Fourier-transform infrared spectroscopy. Solid-state nuclear magnetic resonance spectroscopy identified β-chitin and additional polysaccharides, for a total amount of 80% of the insoluble fraction. Proteomics was applied to both soluble and insoluble matrices and in silico searches were performed, first on heterologous metazoans models, and secondly, on an unpublished transcriptome of Spirula spirula. In the first case, several peptides were identified, some of them matching with tyrosinase, chitinase 2, protease inhibitor, or immunoglobulin. In the second case, 38 hits were obtained, including transferrin, a serine protease inhibitor, matrilin, different histone-like, a 2-macroglobulin or a putative heme-binding/calcium-binding protein. The very few similarities with known molluscan shell matrix proteins suggest that Spirula spirula uses a unique set of shell matrix proteins for constructing its internal shell. The absence of similarity with closely related cephalopods such as the cuttlefish Sepia demonstrates that there is no obvious phylogenetic signal in the skeletal matrix of cephalopods.

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Section: Ft-ir Spectroscopymentioning

confidence: 79%

The shell matrix and microstructure of the Ram’s Horn squid: Molecular and structural characterization

Oudot

Neige

Shir

et al. 2020

Journal of Structural Biology

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“…This band in the glass S75C16‐4 splits into 2 distinct peaks at 1085 and 1049 cm −1 , as a result of interaction of the carbon and silica . This is accompanied by the evolution of the 880 (879) cm −1 peak, related to the CO 3 2− group, which could be attributed to the substitution of phosphate ions in B‐type hydroxyapatite (HAp), which can even result in carbonate apatite. This is probably due to carbonate residues as this sample was synthesized with the higher amount of citric acid.…”

Section: Resultsmentioning

confidence: 99%

Effects of catalysts on polymerization and microstructure of sol‐gel derived bioglasses

et al. 2018

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This work investigates the effects of the type and concentration of acid catalysts on the microstructural features of silica‐rich bioactive glasses (75Si–16Ca–5Na–4P, in mol%) synthesized from acetate and nitrate precursor salts, using an innovative rapid sol‐gel method, followed by thermal stabilization at 550°C. The results of XRD, SEM, Fourier Transform Infrared Spectrometer (FTIR) and solid state MAS NMR analysis revealed that the lower degrees of polymerization and network connectivity were found for bioglass powders obtained in the presence of high acid concentrations. A low amount of citric acid gave a polymerization degree similar to that obtained in the absence of any catalyst, but the synthesis time was as short as that found for high acid concentrations. The XRD and FTIR results demonstrated amorphous glass powders free of any nitrate by‐products. The microstructure and degree of polymerization could be modified by changing the type and concentration of acid catalyst, enabling one to tailor the bioactivity of glasses even without changing the starting composition.

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“…Bands at 1414 cm -1 (ASM1-2) can be attributed to δ(C−H) scissoring vibration while those at 1223 (ASM2), 1224 (ASM1) and 1225 cm -1 (AIM1) are assigned to amide III vibrations (CN stretching, NH bending). Moreover, the weak bands at 1124 cm -1 (ASM1-2) associated to the absorptions pointed at 537 and 576 cm -1 (shoulders), suggest the presence of phosphate groups (PO 4 3− ) [40] and can be related to P-O stretching and O-P-O bending vibrations, respectively [41]. Note that ASM1 and ASM2 spectra are almost superimposable and exhibit the same distribution of absorption bands with similar intensities, with only slight shifts.…”

Section: Ft-ir Spectroscopymentioning

confidence: 99%

A Nature’s Curiosity: The Argonaut “Shell” and Its Organic Content

et al. 2020

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Molluscs are known for their ability to produce a calcified shell resulting from a genetically controlled and matrix-mediated process, performed extracellularly. The occluded organic matrix consists of a complex mixture of proteins, glycoproteins and polysaccharides that are in most cases secreted by the mantle epithelium. To our knowledge, the model studied here—the argonaut, also called paper nautilus—represents the single mollusc example where this general scheme is not valid: the shell of this cephalopod is indeed formed by its first dorsal arms pair and it functions as an eggcase, secreted by females only; furthermore, this coiled structure is fully calcitic and the organization of its layered microstructures is unique. Thus, the argonautid shell appears as an apomorphy of this restricted family, not homologous to other cephalopod shells. In the present study, we investigated the physical and biochemical properties of the shell of Argonauta hians, the winged argonaut. We show that the shell matrix contains unusual proportions of soluble and insoluble components, and that it is mostly proteinaceous, with a low proportion of sugars that appear to be mostly sulfated glycosaminoglycans. Proteomics performed on different shell fractions generated several peptide sequences and identified a number of protein hits, not shared with other molluscan shell matrices. This may suggest the recruitment of unique molecular tools for mineralizing the argonaut’s shell, a finding that has some implications on the evolution of cephalopod shell matrices.

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<i>In </i><i>V</i><i>itro</i>Bioactivity of Collagen/Calcium Phosphate Silicate Composites, Cross-Linked with Chondroitin Sulfate

Cited by 12 publications

References 39 publications

The shell matrix and microstructure of the Ram’s Horn squid: Molecular and structural characterization

The shell matrix and microstructure of the Ram’s Horn squid: Molecular and structural characterization

Effects of catalysts on polymerization and microstructure of sol‐gel derived bioglasses

A Nature’s Curiosity: The Argonaut “Shell” and Its Organic Content

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