Influence of Metal Ions on the Melting Temperature, Modulus, and Gelation Time of Gelatin Gels: Specific Ion Effects on Hydrogel Properties.

The impact of ions on hydrogel strength is not well understood, in particular with regards to specific ion effects for cations. Herein, we find that divalent and monovalent cations in most cases reduce the modulus and melting temperature while increasing the gelation time of gelatin hydrogels. This behavior is in contrast to the well-known stiffening effect of trivalent metals.

Modification of bone-like apatite nanoparticle size and growth kinetics by alizarin red S.

The formation of nanocrystals in biomineralization such as in bone occurs under the influence of organic molecules. Prompted by this fact, the effect of alizarin red S, a dye used in in vivo bone labeling methods, on bone-like carbonated apatite nanocrystal formation was investigated as a function of alizarin red S additive concentration. The obtained nanoparticles were investigated by powder X-ray diffraction (XRD), FTIR as well thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) while the kinetics of nanoparticle formation was investigated by in situ pH and synchrotron XRD measurements.