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Ionic solutes impact collagen scaffold bioactivity.

Pawelec KM, Husmann A, Wardale RJ, Best SM, Cameron RE - J Mater Sci Mater Med (2015)

Bottom Line: The structure of ice-templated collagen scaffolds is sensitive to many factors.By adding 0.5 wt% of sodium chloride or sucrose to collagen slurries, scaffold structure could be tuned through changes in ice growth kinetics and interactions of the solute and collagen.This highlights the large changes in structure and biological function stimulated by solutes in ice-templating systems.

View Article: PubMed Central - PubMed

Affiliation: Materials Science and Metallurgy Department, Cambridge Centre for Medical Materials, University of Cambridge, Cambridge, CB3 0FS, UK, pawelec.km@gmail.com.

ABSTRACT
The structure of ice-templated collagen scaffolds is sensitive to many factors. By adding 0.5 wt% of sodium chloride or sucrose to collagen slurries, scaffold structure could be tuned through changes in ice growth kinetics and interactions of the solute and collagen. With ionic solutes (sodium chloride) the entanglements of the collagen molecule decreased, leading to fibrous scaffolds with increased pore size and decreased attachment of chondrocytes. With non-ionic solutes (sucrose) ice growth was slowed, leading to significantly reduced pore size and up-regulated cell attachment. This highlights the large changes in structure and biological function stimulated by solutes in ice-templating systems.

Show MeSH
Collagen scaffold structure and the rheological properties of the slurry were affected by solute additions. Addition of 0.5 wt% NaCl changed the conformation of the collagen, altering a the viscosity of the slurry, and b the storage (G′) and elastic moduli (G″). Collagen scaffold structure with c no solute addition, d 0.5 wt% sucrose, and e 5 wt% sucrose and f 0.5 wt% NaCl; scale bar is 100 μm. The fibrillar structure of scaffolds with 0.5 wt% NaCl is clearly visible at higher magnification g ×400 and h ×3,300
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Fig1: Collagen scaffold structure and the rheological properties of the slurry were affected by solute additions. Addition of 0.5 wt% NaCl changed the conformation of the collagen, altering a the viscosity of the slurry, and b the storage (G′) and elastic moduli (G″). Collagen scaffold structure with c no solute addition, d 0.5 wt% sucrose, and e 5 wt% sucrose and f 0.5 wt% NaCl; scale bar is 100 μm. The fibrillar structure of scaffolds with 0.5 wt% NaCl is clearly visible at higher magnification g ×400 and h ×3,300

Mentions: The collagen reacted strongly to the addition of an ionic solute, and after 0.5 wt% NaCl, the insoluble flakes came out of suspension. Thus 0.5 wt% was the limit of NaCl addition. Electrostatic interactions play a large role in the fibrillogenesis of collagen, with ionic additions retarding the rate of fibrillogenesis and altering the charge of collagen molecules within solutions [9, 13]. While the insoluble collagen used in the current study should not undergo fibrillogenesis, the charge on the molecules would still be sensitive to the addition of NaCl. In the case of sucrose addition, while the collagen remained in suspension after 5 wt% sucrose, excess sucrose crystallized onto the scaffold pore walls, Fig. 1. After washing the scaffold to remove the sucrose, the collagen structure remained brittle and inelastic, and thus, experiments were only carried out using 0.5 wt% sucrose.Fig. 1


Ionic solutes impact collagen scaffold bioactivity.

Pawelec KM, Husmann A, Wardale RJ, Best SM, Cameron RE - J Mater Sci Mater Med (2015)

Collagen scaffold structure and the rheological properties of the slurry were affected by solute additions. Addition of 0.5 wt% NaCl changed the conformation of the collagen, altering a the viscosity of the slurry, and b the storage (G′) and elastic moduli (G″). Collagen scaffold structure with c no solute addition, d 0.5 wt% sucrose, and e 5 wt% sucrose and f 0.5 wt% NaCl; scale bar is 100 μm. The fibrillar structure of scaffolds with 0.5 wt% NaCl is clearly visible at higher magnification g ×400 and h ×3,300
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4381095&req=5

Fig1: Collagen scaffold structure and the rheological properties of the slurry were affected by solute additions. Addition of 0.5 wt% NaCl changed the conformation of the collagen, altering a the viscosity of the slurry, and b the storage (G′) and elastic moduli (G″). Collagen scaffold structure with c no solute addition, d 0.5 wt% sucrose, and e 5 wt% sucrose and f 0.5 wt% NaCl; scale bar is 100 μm. The fibrillar structure of scaffolds with 0.5 wt% NaCl is clearly visible at higher magnification g ×400 and h ×3,300
Mentions: The collagen reacted strongly to the addition of an ionic solute, and after 0.5 wt% NaCl, the insoluble flakes came out of suspension. Thus 0.5 wt% was the limit of NaCl addition. Electrostatic interactions play a large role in the fibrillogenesis of collagen, with ionic additions retarding the rate of fibrillogenesis and altering the charge of collagen molecules within solutions [9, 13]. While the insoluble collagen used in the current study should not undergo fibrillogenesis, the charge on the molecules would still be sensitive to the addition of NaCl. In the case of sucrose addition, while the collagen remained in suspension after 5 wt% sucrose, excess sucrose crystallized onto the scaffold pore walls, Fig. 1. After washing the scaffold to remove the sucrose, the collagen structure remained brittle and inelastic, and thus, experiments were only carried out using 0.5 wt% sucrose.Fig. 1

Bottom Line: The structure of ice-templated collagen scaffolds is sensitive to many factors.By adding 0.5 wt% of sodium chloride or sucrose to collagen slurries, scaffold structure could be tuned through changes in ice growth kinetics and interactions of the solute and collagen.This highlights the large changes in structure and biological function stimulated by solutes in ice-templating systems.

View Article: PubMed Central - PubMed

Affiliation: Materials Science and Metallurgy Department, Cambridge Centre for Medical Materials, University of Cambridge, Cambridge, CB3 0FS, UK, pawelec.km@gmail.com.

ABSTRACT
The structure of ice-templated collagen scaffolds is sensitive to many factors. By adding 0.5 wt% of sodium chloride or sucrose to collagen slurries, scaffold structure could be tuned through changes in ice growth kinetics and interactions of the solute and collagen. With ionic solutes (sodium chloride) the entanglements of the collagen molecule decreased, leading to fibrous scaffolds with increased pore size and decreased attachment of chondrocytes. With non-ionic solutes (sucrose) ice growth was slowed, leading to significantly reduced pore size and up-regulated cell attachment. This highlights the large changes in structure and biological function stimulated by solutes in ice-templating systems.

Show MeSH