Effect of Gelatin Gelation Kinetics on Probe Diffusion Determined by FRAP and Rheology
Journal article, 2010

The time-dependent diffusion and mechanical properties of gelatin in solution, in the gel state, and during the sol/gel transition were determined using fluorescence recovery after photobleaching (FRAP) and rheology. The parameters in the experimental design were 2% w/w and 5% w/w gelatin concentration; 15, 20, and 25 degrees C end quench temperatures; and Na-2-fluorescein, 10 kDa FITC-dextran, and 500 kDa FITC-dextran as diffusion probes. The samples were monitored in solution at 60 degrees C, during quenching, for 75 min at end quench temperatures and after 1, 7, and 14 days of storage at the end quench temperature. The effect of temperature on the probe diffusion was normalized by determining the free diffusion of the probes in pure water for the different temperatures. The results gained by comparing FRAP and rheology showed that FRAP is able to capture structural changes in the gelatin before gelation occurs, which was interpreted as a formation of transient networks. This was clearly seen for 2% w/w gelatin and 20 and 25 degrees C end quench temperatures. The structural changes during sol/gel transition are detected only by the larger probes, giving information about the typical length scales in the gelatin structure. The normalized diffusion rate increased after 7 and 14 days of storage. This increase was most pronounced for fluorescein but was also seen for the larger probes.

diffusion

microscopy

proteins

nmr

kappa-carrageenan

collagen gels

solute

transition

fluorescence photobleaching recovery

Author

Joel H Hagman

SuMo Biomaterials

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Niklas Lorén

SuMo Biomaterials

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Anne-Marie Hermansson

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

SuMo Biomaterials

Biomacromolecules

1525-7797 (ISSN) 1526-4602 (eISSN)

Vol. 11 12 3359-3366

Subject Categories

Chemical Engineering

DOI

10.1021/bm1008487

More information

Latest update

8/18/2020