Study of the molecular mobility of collagen

Mezghani, S.; Lamure, A.; Lacabanne, C.

doi:10.1002/polb.1995.090331712

Cited by 11 publications

(7 citation statements)

References 19 publications

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“…Finally, complementary studies on lyophilized collagen from immature rat skin have allowed us to bring to the fore such a doublet of denaturation 42…”

Section: Resultsmentioning

confidence: 99%

Characterization of aneurysmal aortas by biochemical, thermal, and dielectric techniques

Samouillan¹,

Dandurand²,

Lacabanne³

et al. 2010

J Biomedical Materials Res

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Abdominal aortic aneurysms (AAA) are characterized by structural alterations of the aortic wall resulting from the degradation of elastic fibres and an increase of collagen/elastin ratio. In this study we investigated the chain dynamics of AAA tissues by two techniques generally used for the characterization of polymers, Differential scanning calorimetry (DSC) and thermally stimulated currents (TSC), and we correlated the obtained data with biochemical analyses. The thermal denaturation of collagen observed by DSC allowed us to evaluate the thermal stability of the triple helix domain: notable modifications were evidenced between collagen from control tissue and collagen from AAA, particularly concerning the thermal denaturation. The dielectric analysis of pathologic aortic walls by TSC revealed a relevant change of collagen mobility in AAA, with the occurrence of a specific mode of relaxation between -60 and -40°C. Biochemical, thermal, and dielectric results are compatible with increase of new collagen deposition and/or impairment of the collagen phase stability in the extracellular matrix of AAAs.

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“…Finally, complementary studies on lyophilized collagen from immature rat skin have allowed us to bring to the fore such a doublet of denaturation 42…”

Section: Resultsmentioning

confidence: 99%

Characterization of aneurysmal aortas by biochemical, thermal, and dielectric techniques

Samouillan¹,

Dandurand²,

Lacabanne³

et al. 2010

J Biomedical Materials Res

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“…24 In the present study, we "sampled" the complex β-relaxation process by polarizing the specimens in the cooling stage within consecutive narrow temperature windows of ∆T ) T 2 -T 1 ) 5 K (-dT/dt ) 5 K/min, t p ) 1 min). 67 At the low-temperature side of each polarizing window (T 1 ), the sample remained shortcircuited for 1 min. The nonequilibrium polarization state is maintained by cooling the sample to T 0 ≈ T 1 -50 K. In each of the subsequent heating stages, we recorded non-Debye current peaks.…”

Section: Resultsmentioning

confidence: 99%

“…A more precise examination of the TSDC spectra has been obtained by using the thermal sampling technique . In the present study, we “sampled” the complex β-relaxation process by polarizing the specimens in the cooling stage within consecutive narrow temperature windows of Δ T = T 2 − T 1 = 5 K (−d T /d t = 5 K/min, t p = 1 min) . At the low-temperature side of each polarizing window ( T 1 ), the sample remained short-circuited for 1 min.…”

Section: Resultsmentioning

confidence: 99%

Dielectric Probe of Intermolecular Interactions in Poly(methyl methacrylate) (PMMA) and PMMA + SiO₂ Matrixes Doped with Luminescent Organics

Kalogeras

Vassilikou‐Dova

2001

J. Phys. Chem. B

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Modifications in the molecular dynamics of the side-chain relaxation in poly(methyl methacrylate) (PMMA) have been recorded by monitoring the thermally stimulated depolarization currents (TSDC) β-relaxation band of PMMA in three systems: bulk PMMA, PMMA polymerized in situ in porous SiO2, and lasing matrixes with rhodamine 6G/Cl- (R6G) and a perylene derivative (PG). To study the different types of inter- and intramolecular interactions, a range of dye concentrations and different polymerization initiators have been tested. In PMMA + SiO2, the low-temperature (LT) shift of the β-band and the increase of the energy barriers (W) associated with the side-chain (re)orientation are attributed to various counterbalancing effects. A scheme of extensive hydrogen-bond interactions (surface or chemical effect) between the ester carbonyls of PMMA and the silicic acid pore surface is used to explain the overall increase in the distributed energy barriers. In contrast, the reduction of the polymer's chain entanglements and the increase in the free volume (structural or physical effect), due to the pore-directed polymerization, are considered to loosen up several steric hindrances on the rotational motion. The modification of the relaxation times spectrum prompts the shift of the β-relaxation in PMMA + SiO2. In R6G + PMMA, the drastic LT shift of the β-band indicates the partial coupling between the chromophores and the side-group rotations. The TSDC spectrum does not present a rotational relaxation of the polar rhodamine dye. In R6G + PMMA + SiO2, the presence of the chromophores on the pore surfaces and the corresponding decrease of the “effective” average pore diameters available for MMA diffusion and PMMA growth balance the physical and chemical effects, as depicted in the similarity of the energy distributions. The speedup of the β-relaxation with increasing dye content is ascribed to the reduced exposure of the side groups to chemical effects. The positive energy shift in PG + PMMA + SiO2 can be explained by considering the mixing of PG and PMMA, which permits strong hydrogen-bonding interactions and simultaneously reduces PMMA's free volume. TSDC signals around room temperature (RT) are tentatively discussed in terms of a Maxwell−Wagner−Sillars (MWS) polarization mode at the PMMA−SiO2 interface.

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“…Therefore, it seems that more water is bound within the acidic collagen films. This bound water has been shown to increase the stiffness of the collagen molecule by facilitating hydrogen bond formation between polar telopeptides in adjacent collagen molecules 36. Although neutral films were significantly less resistant with respect to ultimate strength, their decreased elastic modulus may be beneficial for vascular tissue engineering as this property, and the inherent compliance, is generally much lower for natural arteries.…”

Section: Discussionmentioning

confidence: 99%

Preparation of Ready‐to‐use, Stockable and Reconstituted Collagen

Habermehl

Skopińska

Boccafoschi

et al. 2005

Macromolecular Bioscience

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Collagen is a widely used material in biomedical applications. Although processes that prepare collagen and collagen-based materials that show suitable properties after extraction exist, a ready-to-use, easily stockable, with tailored collagen concentration has not yet been developed. Using rat tail tendons, acid soluble collagen solutions were prepared by two different methods. To improve cell viability of pure collagen films, solutions with physiological pH were also prepared by mixing with NaOH solution. Specimens in the form of thin sheets were then fabricated by solvent evaporation. Next, IR spectroscopy, tensile testing techniques as well as human fibroblast cell morphology and cytotoxicity were used to validate the significant variations in the processes. The results demonstrated that, during the synthesis of collagen stock solution, lyophilization and mechanical blending had little effect on the final properties and therefore offers a method for obtaining solutions with a more homogeneous and modifiable collagen concentration and longer storage time. Neutralizing the stock solution with aqueous NaOH prior to solvent evaporation provided films that had lower mechanical properties but significantly improved biological performance.

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Study of the molecular mobility of collagen

Cited by 11 publications

References 19 publications

Characterization of aneurysmal aortas by biochemical, thermal, and dielectric techniques

Characterization of aneurysmal aortas by biochemical, thermal, and dielectric techniques

Dielectric Probe of Intermolecular Interactions in Poly(methyl methacrylate) (PMMA) and PMMA + SiO₂ Matrixes Doped with Luminescent Organics

Preparation of Ready‐to‐use, Stockable and Reconstituted Collagen

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Study of the molecular mobility of collagen

Cited by 11 publications

References 19 publications

Characterization of aneurysmal aortas by biochemical, thermal, and dielectric techniques

Characterization of aneurysmal aortas by biochemical, thermal, and dielectric techniques

Dielectric Probe of Intermolecular Interactions in Poly(methyl methacrylate) (PMMA) and PMMA + SiO2 Matrixes Doped with Luminescent Organics

Preparation of Ready‐to‐use, Stockable and Reconstituted Collagen

Contact Info

Product

Resources

About

Dielectric Probe of Intermolecular Interactions in Poly(methyl methacrylate) (PMMA) and PMMA + SiO₂ Matrixes Doped with Luminescent Organics